postgresql/src/backend/commands/explain.c

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/*-------------------------------------------------------------------------
*
* explain.c
* Explain query execution plans
*
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* Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
* Portions Copyright (c) 1994-5, Regents of the University of California
*
* IDENTIFICATION
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* src/backend/commands/explain.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
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#include "access/xact.h"
#include "catalog/pg_collation.h"
#include "catalog/pg_type.h"
#include "commands/createas.h"
#include "commands/defrem.h"
#include "commands/prepare.h"
#include "executor/hashjoin.h"
#include "foreign/fdwapi.h"
#include "nodes/extensible.h"
#include "nodes/nodeFuncs.h"
#include "optimizer/clauses.h"
#include "optimizer/planmain.h"
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#include "parser/parsetree.h"
#include "rewrite/rewriteHandler.h"
#include "storage/bufmgr.h"
#include "tcop/tcopprot.h"
#include "utils/builtins.h"
#include "utils/json.h"
#include "utils/lsyscache.h"
#include "utils/rel.h"
#include "utils/ruleutils.h"
#include "utils/snapmgr.h"
#include "utils/tuplesort.h"
#include "utils/typcache.h"
#include "utils/xml.h"
/* Hook for plugins to get control in ExplainOneQuery() */
ExplainOneQuery_hook_type ExplainOneQuery_hook = NULL;
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/* Hook for plugins to get control in explain_get_index_name() */
explain_get_index_name_hook_type explain_get_index_name_hook = NULL;
/* OR-able flags for ExplainXMLTag() */
#define X_OPENING 0
#define X_CLOSING 1
#define X_CLOSE_IMMEDIATE 2
#define X_NOWHITESPACE 4
Change representation of statement lists, and add statement location info. This patch makes several changes that improve the consistency of representation of lists of statements. It's always been the case that the output of parse analysis is a list of Query nodes, whatever the types of the individual statements in the list. This patch brings similar consistency to the outputs of raw parsing and planning steps: * The output of raw parsing is now always a list of RawStmt nodes; the statement-type-dependent nodes are one level down from that. * The output of pg_plan_queries() is now always a list of PlannedStmt nodes, even for utility statements. In the case of a utility statement, "planning" just consists of wrapping a CMD_UTILITY PlannedStmt around the utility node. This list representation is now used in Portal and CachedPlan plan lists, replacing the former convention of intermixing PlannedStmts with bare utility-statement nodes. Now, every list of statements has a consistent head-node type depending on how far along it is in processing. This allows changing many places that formerly used generic "Node *" pointers to use a more specific pointer type, thus reducing the number of IsA() tests and casts needed, as well as improving code clarity. Also, the post-parse-analysis representation of DECLARE CURSOR is changed so that it looks more like EXPLAIN, PREPARE, etc. That is, the contained SELECT remains a child of the DeclareCursorStmt rather than getting flipped around to be the other way. It's now true for both Query and PlannedStmt that utilityStmt is non-null if and only if commandType is CMD_UTILITY. That allows simplifying a lot of places that were testing both fields. (I think some of those were just defensive programming, but in many places, it was actually necessary to avoid confusing DECLARE CURSOR with SELECT.) Because PlannedStmt carries a canSetTag field, we're also able to get rid of some ad-hoc rules about how to reconstruct canSetTag for a bare utility statement; specifically, the assumption that a utility is canSetTag if and only if it's the only one in its list. While I see no near-term need for relaxing that restriction, it's nice to get rid of the ad-hocery. The API of ProcessUtility() is changed so that what it's passed is the wrapper PlannedStmt not just the bare utility statement. This will affect all users of ProcessUtility_hook, but the changes are pretty trivial; see the affected contrib modules for examples of the minimum change needed. (Most compilers should give pointer-type-mismatch warnings for uncorrected code.) There's also a change in the API of ExplainOneQuery_hook, to pass through cursorOptions instead of expecting hook functions to know what to pick. This is needed because of the DECLARE CURSOR changes, but really should have been done in 9.6; it's unlikely that any extant hook functions know about using CURSOR_OPT_PARALLEL_OK. Finally, teach gram.y to save statement boundary locations in RawStmt nodes, and pass those through to Query and PlannedStmt nodes. This allows more intelligent handling of cases where a source query string contains multiple statements. This patch doesn't actually do anything with the information, but a follow-on patch will. (Passing this information through cleanly is the true motivation for these changes; while I think this is all good cleanup, it's unlikely we'd have bothered without this end goal.) catversion bump because addition of location fields to struct Query affects stored rules. This patch is by me, but it owes a good deal to Fabien Coelho who did a lot of preliminary work on the problem, and also reviewed the patch. Discussion: https://postgr.es/m/alpine.DEB.2.20.1612200926310.29821@lancre
2017-01-14 22:02:35 +01:00
static void ExplainOneQuery(Query *query, int cursorOptions,
IntoClause *into, ExplainState *es,
const char *queryString, ParamListInfo params,
QueryEnvironment *queryEnv);
static void report_triggers(ResultRelInfo *rInfo, bool show_relname,
ExplainState *es);
static double elapsed_time(instr_time *starttime);
static bool ExplainPreScanNode(PlanState *planstate, Bitmapset **rels_used);
static void ExplainNode(PlanState *planstate, List *ancestors,
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const char *relationship, const char *plan_name,
ExplainState *es);
static void show_plan_tlist(PlanState *planstate, List *ancestors,
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ExplainState *es);
static void show_expression(Node *node, const char *qlabel,
PlanState *planstate, List *ancestors,
bool useprefix, ExplainState *es);
static void show_qual(List *qual, const char *qlabel,
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PlanState *planstate, List *ancestors,
bool useprefix, ExplainState *es);
static void show_scan_qual(List *qual, const char *qlabel,
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PlanState *planstate, List *ancestors,
ExplainState *es);
static void show_upper_qual(List *qual, const char *qlabel,
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PlanState *planstate, List *ancestors,
ExplainState *es);
static void show_sort_keys(SortState *sortstate, List *ancestors,
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ExplainState *es);
static void show_merge_append_keys(MergeAppendState *mstate, List *ancestors,
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ExplainState *es);
static void show_agg_keys(AggState *astate, List *ancestors,
ExplainState *es);
Support GROUPING SETS, CUBE and ROLLUP. This SQL standard functionality allows to aggregate data by different GROUP BY clauses at once. Each grouping set returns rows with columns grouped by in other sets set to NULL. This could previously be achieved by doing each grouping as a separate query, conjoined by UNION ALLs. Besides being considerably more concise, grouping sets will in many cases be faster, requiring only one scan over the underlying data. The current implementation of grouping sets only supports using sorting for input. Individual sets that share a sort order are computed in one pass. If there are sets that don't share a sort order, additional sort & aggregation steps are performed. These additional passes are sourced by the previous sort step; thus avoiding repeated scans of the source data. The code is structured in a way that adding support for purely using hash aggregation or a mix of hashing and sorting is possible. Sorting was chosen to be supported first, as it is the most generic method of implementation. Instead of, as in an earlier versions of the patch, representing the chain of sort and aggregation steps as full blown planner and executor nodes, all but the first sort are performed inside the aggregation node itself. This avoids the need to do some unusual gymnastics to handle having to return aggregated and non-aggregated tuples from underlying nodes, as well as having to shut down underlying nodes early to limit memory usage. The optimizer still builds Sort/Agg node to describe each phase, but they're not part of the plan tree, but instead additional data for the aggregation node. They're a convenient and preexisting way to describe aggregation and sorting. The first (and possibly only) sort step is still performed as a separate execution step. That retains similarity with existing group by plans, makes rescans fairly simple, avoids very deep plans (leading to slow explains) and easily allows to avoid the sorting step if the underlying data is sorted by other means. A somewhat ugly side of this patch is having to deal with a grammar ambiguity between the new CUBE keyword and the cube extension/functions named cube (and rollup). To avoid breaking existing deployments of the cube extension it has not been renamed, neither has cube been made a reserved keyword. Instead precedence hacking is used to make GROUP BY cube(..) refer to the CUBE grouping sets feature, and not the function cube(). To actually group by a function cube(), unlikely as that might be, the function name has to be quoted. Needs a catversion bump because stored rules may change. Author: Andrew Gierth and Atri Sharma, with contributions from Andres Freund Reviewed-By: Andres Freund, Noah Misch, Tom Lane, Svenne Krap, Tomas Vondra, Erik Rijkers, Marti Raudsepp, Pavel Stehule Discussion: CAOeZVidmVRe2jU6aMk_5qkxnB7dfmPROzM7Ur8JPW5j8Y5X-Lw@mail.gmail.com
2015-05-16 03:40:59 +02:00
static void show_grouping_sets(PlanState *planstate, Agg *agg,
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List *ancestors, ExplainState *es);
Support GROUPING SETS, CUBE and ROLLUP. This SQL standard functionality allows to aggregate data by different GROUP BY clauses at once. Each grouping set returns rows with columns grouped by in other sets set to NULL. This could previously be achieved by doing each grouping as a separate query, conjoined by UNION ALLs. Besides being considerably more concise, grouping sets will in many cases be faster, requiring only one scan over the underlying data. The current implementation of grouping sets only supports using sorting for input. Individual sets that share a sort order are computed in one pass. If there are sets that don't share a sort order, additional sort & aggregation steps are performed. These additional passes are sourced by the previous sort step; thus avoiding repeated scans of the source data. The code is structured in a way that adding support for purely using hash aggregation or a mix of hashing and sorting is possible. Sorting was chosen to be supported first, as it is the most generic method of implementation. Instead of, as in an earlier versions of the patch, representing the chain of sort and aggregation steps as full blown planner and executor nodes, all but the first sort are performed inside the aggregation node itself. This avoids the need to do some unusual gymnastics to handle having to return aggregated and non-aggregated tuples from underlying nodes, as well as having to shut down underlying nodes early to limit memory usage. The optimizer still builds Sort/Agg node to describe each phase, but they're not part of the plan tree, but instead additional data for the aggregation node. They're a convenient and preexisting way to describe aggregation and sorting. The first (and possibly only) sort step is still performed as a separate execution step. That retains similarity with existing group by plans, makes rescans fairly simple, avoids very deep plans (leading to slow explains) and easily allows to avoid the sorting step if the underlying data is sorted by other means. A somewhat ugly side of this patch is having to deal with a grammar ambiguity between the new CUBE keyword and the cube extension/functions named cube (and rollup). To avoid breaking existing deployments of the cube extension it has not been renamed, neither has cube been made a reserved keyword. Instead precedence hacking is used to make GROUP BY cube(..) refer to the CUBE grouping sets feature, and not the function cube(). To actually group by a function cube(), unlikely as that might be, the function name has to be quoted. Needs a catversion bump because stored rules may change. Author: Andrew Gierth and Atri Sharma, with contributions from Andres Freund Reviewed-By: Andres Freund, Noah Misch, Tom Lane, Svenne Krap, Tomas Vondra, Erik Rijkers, Marti Raudsepp, Pavel Stehule Discussion: CAOeZVidmVRe2jU6aMk_5qkxnB7dfmPROzM7Ur8JPW5j8Y5X-Lw@mail.gmail.com
2015-05-16 03:40:59 +02:00
static void show_grouping_set_keys(PlanState *planstate,
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Agg *aggnode, Sort *sortnode,
List *context, bool useprefix,
List *ancestors, ExplainState *es);
static void show_group_keys(GroupState *gstate, List *ancestors,
ExplainState *es);
static void show_sort_group_keys(PlanState *planstate, const char *qlabel,
int nkeys, AttrNumber *keycols,
Oid *sortOperators, Oid *collations, bool *nullsFirst,
List *ancestors, ExplainState *es);
static void show_sortorder_options(StringInfo buf, Node *sortexpr,
Oid sortOperator, Oid collation, bool nullsFirst);
Redesign tablesample method API, and do extensive code review. The original implementation of TABLESAMPLE modeled the tablesample method API on index access methods, which wasn't a good choice because, without specialized DDL commands, there's no way to build an extension that can implement a TSM. (Raw inserts into system catalogs are not an acceptable thing to do, because we can't undo them during DROP EXTENSION, nor will pg_upgrade behave sanely.) Instead adopt an API more like procedural language handlers or foreign data wrappers, wherein the only SQL-level support object needed is a single handler function identified by having a special return type. This lets us get rid of the supporting catalog altogether, so that no custom DDL support is needed for the feature. Adjust the API so that it can support non-constant tablesample arguments (the original coding assumed we could evaluate the argument expressions at ExecInitSampleScan time, which is undesirable even if it weren't outright unsafe), and discourage sampling methods from looking at invisible tuples. Make sure that the BERNOULLI and SYSTEM methods are genuinely repeatable within and across queries, as required by the SQL standard, and deal more honestly with methods that can't support that requirement. Make a full code-review pass over the tablesample additions, and fix assorted bugs, omissions, infelicities, and cosmetic issues (such as failure to put the added code stanzas in a consistent ordering). Improve EXPLAIN's output of tablesample plans, too. Back-patch to 9.5 so that we don't have to support the original API in production.
2015-07-25 20:39:00 +02:00
static void show_tablesample(TableSampleClause *tsc, PlanState *planstate,
List *ancestors, ExplainState *es);
static void show_sort_info(SortState *sortstate, ExplainState *es);
static void show_hash_info(HashState *hashstate, ExplainState *es);
static void show_tidbitmap_info(BitmapHeapScanState *planstate,
ExplainState *es);
static void show_instrumentation_count(const char *qlabel, int which,
PlanState *planstate, ExplainState *es);
static void show_foreignscan_info(ForeignScanState *fsstate, ExplainState *es);
static const char *explain_get_index_name(Oid indexId);
static void show_buffer_usage(ExplainState *es, const BufferUsage *usage);
static void ExplainIndexScanDetails(Oid indexid, ScanDirection indexorderdir,
ExplainState *es);
static void ExplainScanTarget(Scan *plan, ExplainState *es);
static void ExplainModifyTarget(ModifyTable *plan, ExplainState *es);
static void ExplainTargetRel(Plan *plan, Index rti, ExplainState *es);
Add support for INSERT ... ON CONFLICT DO NOTHING/UPDATE. The newly added ON CONFLICT clause allows to specify an alternative to raising a unique or exclusion constraint violation error when inserting. ON CONFLICT refers to constraints that can either be specified using a inference clause (by specifying the columns of a unique constraint) or by naming a unique or exclusion constraint. DO NOTHING avoids the constraint violation, without touching the pre-existing row. DO UPDATE SET ... [WHERE ...] updates the pre-existing tuple, and has access to both the tuple proposed for insertion and the existing tuple; the optional WHERE clause can be used to prevent an update from being executed. The UPDATE SET and WHERE clauses have access to the tuple proposed for insertion using the "magic" EXCLUDED alias, and to the pre-existing tuple using the table name or its alias. This feature is often referred to as upsert. This is implemented using a new infrastructure called "speculative insertion". It is an optimistic variant of regular insertion that first does a pre-check for existing tuples and then attempts an insert. If a violating tuple was inserted concurrently, the speculatively inserted tuple is deleted and a new attempt is made. If the pre-check finds a matching tuple the alternative DO NOTHING or DO UPDATE action is taken. If the insertion succeeds without detecting a conflict, the tuple is deemed inserted. To handle the possible ambiguity between the excluded alias and a table named excluded, and for convenience with long relation names, INSERT INTO now can alias its target table. Bumps catversion as stored rules change. Author: Peter Geoghegan, with significant contributions from Heikki Linnakangas and Andres Freund. Testing infrastructure by Jeff Janes. Reviewed-By: Heikki Linnakangas, Andres Freund, Robert Haas, Simon Riggs, Dean Rasheed, Stephen Frost and many others.
2015-05-08 05:31:36 +02:00
static void show_modifytable_info(ModifyTableState *mtstate, List *ancestors,
ExplainState *es);
static void ExplainMemberNodes(List *plans, PlanState **planstates,
List *ancestors, ExplainState *es);
static void ExplainSubPlans(List *plans, List *ancestors,
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const char *relationship, ExplainState *es);
static void ExplainCustomChildren(CustomScanState *css,
Redesign tablesample method API, and do extensive code review. The original implementation of TABLESAMPLE modeled the tablesample method API on index access methods, which wasn't a good choice because, without specialized DDL commands, there's no way to build an extension that can implement a TSM. (Raw inserts into system catalogs are not an acceptable thing to do, because we can't undo them during DROP EXTENSION, nor will pg_upgrade behave sanely.) Instead adopt an API more like procedural language handlers or foreign data wrappers, wherein the only SQL-level support object needed is a single handler function identified by having a special return type. This lets us get rid of the supporting catalog altogether, so that no custom DDL support is needed for the feature. Adjust the API so that it can support non-constant tablesample arguments (the original coding assumed we could evaluate the argument expressions at ExecInitSampleScan time, which is undesirable even if it weren't outright unsafe), and discourage sampling methods from looking at invisible tuples. Make sure that the BERNOULLI and SYSTEM methods are genuinely repeatable within and across queries, as required by the SQL standard, and deal more honestly with methods that can't support that requirement. Make a full code-review pass over the tablesample additions, and fix assorted bugs, omissions, infelicities, and cosmetic issues (such as failure to put the added code stanzas in a consistent ordering). Improve EXPLAIN's output of tablesample plans, too. Back-patch to 9.5 so that we don't have to support the original API in production.
2015-07-25 20:39:00 +02:00
List *ancestors, ExplainState *es);
static void ExplainProperty(const char *qlabel, const char *value,
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bool numeric, ExplainState *es);
static void ExplainOpenGroup(const char *objtype, const char *labelname,
bool labeled, ExplainState *es);
static void ExplainCloseGroup(const char *objtype, const char *labelname,
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bool labeled, ExplainState *es);
static void ExplainDummyGroup(const char *objtype, const char *labelname,
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ExplainState *es);
static void ExplainXMLTag(const char *tagname, int flags, ExplainState *es);
static void ExplainJSONLineEnding(ExplainState *es);
static void ExplainYAMLLineStarting(ExplainState *es);
static void escape_yaml(StringInfo buf, const char *str);
/*
* ExplainQuery -
* execute an EXPLAIN command
*/
void
ExplainQuery(ParseState *pstate, ExplainStmt *stmt, const char *queryString,
ParamListInfo params, QueryEnvironment *queryEnv,
DestReceiver *dest)
{
ExplainState *es = NewExplainState();
TupOutputState *tstate;
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List *rewritten;
ListCell *lc;
bool timing_set = false;
bool summary_set = false;
/* Parse options list. */
foreach(lc, stmt->options)
{
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DefElem *opt = (DefElem *) lfirst(lc);
if (strcmp(opt->defname, "analyze") == 0)
es->analyze = defGetBoolean(opt);
else if (strcmp(opt->defname, "verbose") == 0)
es->verbose = defGetBoolean(opt);
else if (strcmp(opt->defname, "costs") == 0)
es->costs = defGetBoolean(opt);
else if (strcmp(opt->defname, "buffers") == 0)
es->buffers = defGetBoolean(opt);
else if (strcmp(opt->defname, "timing") == 0)
{
timing_set = true;
es->timing = defGetBoolean(opt);
}
else if (strcmp(opt->defname, "summary") == 0)
{
summary_set = true;
es->summary = defGetBoolean(opt);
}
else if (strcmp(opt->defname, "format") == 0)
{
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char *p = defGetString(opt);
if (strcmp(p, "text") == 0)
es->format = EXPLAIN_FORMAT_TEXT;
else if (strcmp(p, "xml") == 0)
es->format = EXPLAIN_FORMAT_XML;
else if (strcmp(p, "json") == 0)
es->format = EXPLAIN_FORMAT_JSON;
else if (strcmp(p, "yaml") == 0)
es->format = EXPLAIN_FORMAT_YAML;
else
ereport(ERROR,
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(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("unrecognized value for EXPLAIN option \"%s\": \"%s\"",
opt->defname, p),
parser_errposition(pstate, opt->location)));
}
else
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("unrecognized EXPLAIN option \"%s\"",
opt->defname),
parser_errposition(pstate, opt->location)));
}
if (es->buffers && !es->analyze)
ereport(ERROR,
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(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("EXPLAIN option BUFFERS requires ANALYZE")));
/* if the timing was not set explicitly, set default value */
es->timing = (timing_set) ? es->timing : es->analyze;
/* check that timing is used with EXPLAIN ANALYZE */
if (es->timing && !es->analyze)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("EXPLAIN option TIMING requires ANALYZE")));
/* if the summary was not set explicitly, set default value */
es->summary = (summary_set) ? es->summary : es->analyze;
/*
* Parse analysis was done already, but we still have to run the rule
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* rewriter. We do not do AcquireRewriteLocks: we assume the query either
* came straight from the parser, or suitable locks were acquired by
* plancache.c.
*
* Because the rewriter and planner tend to scribble on the input, we make
* a preliminary copy of the source querytree. This prevents problems in
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* the case that the EXPLAIN is in a portal or plpgsql function and is
* executed repeatedly. (See also the same hack in DECLARE CURSOR and
* PREPARE.) XXX FIXME someday.
*/
rewritten = QueryRewrite(castNode(Query, copyObject(stmt->query)));
/* emit opening boilerplate */
ExplainBeginOutput(es);
if (rewritten == NIL)
{
/*
* In the case of an INSTEAD NOTHING, tell at least that. But in
* non-text format, the output is delimited, so this isn't necessary.
*/
if (es->format == EXPLAIN_FORMAT_TEXT)
appendStringInfoString(es->str, "Query rewrites to nothing\n");
}
else
{
ListCell *l;
/* Explain every plan */
foreach(l, rewritten)
{
ExplainOneQuery(lfirst_node(Query, l),
Change representation of statement lists, and add statement location info. This patch makes several changes that improve the consistency of representation of lists of statements. It's always been the case that the output of parse analysis is a list of Query nodes, whatever the types of the individual statements in the list. This patch brings similar consistency to the outputs of raw parsing and planning steps: * The output of raw parsing is now always a list of RawStmt nodes; the statement-type-dependent nodes are one level down from that. * The output of pg_plan_queries() is now always a list of PlannedStmt nodes, even for utility statements. In the case of a utility statement, "planning" just consists of wrapping a CMD_UTILITY PlannedStmt around the utility node. This list representation is now used in Portal and CachedPlan plan lists, replacing the former convention of intermixing PlannedStmts with bare utility-statement nodes. Now, every list of statements has a consistent head-node type depending on how far along it is in processing. This allows changing many places that formerly used generic "Node *" pointers to use a more specific pointer type, thus reducing the number of IsA() tests and casts needed, as well as improving code clarity. Also, the post-parse-analysis representation of DECLARE CURSOR is changed so that it looks more like EXPLAIN, PREPARE, etc. That is, the contained SELECT remains a child of the DeclareCursorStmt rather than getting flipped around to be the other way. It's now true for both Query and PlannedStmt that utilityStmt is non-null if and only if commandType is CMD_UTILITY. That allows simplifying a lot of places that were testing both fields. (I think some of those were just defensive programming, but in many places, it was actually necessary to avoid confusing DECLARE CURSOR with SELECT.) Because PlannedStmt carries a canSetTag field, we're also able to get rid of some ad-hoc rules about how to reconstruct canSetTag for a bare utility statement; specifically, the assumption that a utility is canSetTag if and only if it's the only one in its list. While I see no near-term need for relaxing that restriction, it's nice to get rid of the ad-hocery. The API of ProcessUtility() is changed so that what it's passed is the wrapper PlannedStmt not just the bare utility statement. This will affect all users of ProcessUtility_hook, but the changes are pretty trivial; see the affected contrib modules for examples of the minimum change needed. (Most compilers should give pointer-type-mismatch warnings for uncorrected code.) There's also a change in the API of ExplainOneQuery_hook, to pass through cursorOptions instead of expecting hook functions to know what to pick. This is needed because of the DECLARE CURSOR changes, but really should have been done in 9.6; it's unlikely that any extant hook functions know about using CURSOR_OPT_PARALLEL_OK. Finally, teach gram.y to save statement boundary locations in RawStmt nodes, and pass those through to Query and PlannedStmt nodes. This allows more intelligent handling of cases where a source query string contains multiple statements. This patch doesn't actually do anything with the information, but a follow-on patch will. (Passing this information through cleanly is the true motivation for these changes; while I think this is all good cleanup, it's unlikely we'd have bothered without this end goal.) catversion bump because addition of location fields to struct Query affects stored rules. This patch is by me, but it owes a good deal to Fabien Coelho who did a lot of preliminary work on the problem, and also reviewed the patch. Discussion: https://postgr.es/m/alpine.DEB.2.20.1612200926310.29821@lancre
2017-01-14 22:02:35 +01:00
CURSOR_OPT_PARALLEL_OK, NULL, es,
queryString, params, queryEnv);
/* Separate plans with an appropriate separator */
if (lnext(l) != NULL)
ExplainSeparatePlans(es);
}
}
/* emit closing boilerplate */
ExplainEndOutput(es);
Assert(es->indent == 0);
/* output tuples */
tstate = begin_tup_output_tupdesc(dest, ExplainResultDesc(stmt));
if (es->format == EXPLAIN_FORMAT_TEXT)
do_text_output_multiline(tstate, es->str->data);
else
do_text_output_oneline(tstate, es->str->data);
end_tup_output(tstate);
pfree(es->str->data);
}
/*
* Create a new ExplainState struct initialized with default options.
*/
ExplainState *
NewExplainState(void)
{
ExplainState *es = (ExplainState *) palloc0(sizeof(ExplainState));
/* Set default options (most fields can be left as zeroes). */
es->costs = true;
/* Prepare output buffer. */
es->str = makeStringInfo();
return es;
}
/*
* ExplainResultDesc -
* construct the result tupledesc for an EXPLAIN
*/
TupleDesc
ExplainResultDesc(ExplainStmt *stmt)
{
TupleDesc tupdesc;
ListCell *lc;
Oid result_type = TEXTOID;
/* Check for XML format option */
foreach(lc, stmt->options)
{
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DefElem *opt = (DefElem *) lfirst(lc);
if (strcmp(opt->defname, "format") == 0)
{
2010-02-26 03:01:40 +01:00
char *p = defGetString(opt);
if (strcmp(p, "xml") == 0)
result_type = XMLOID;
else if (strcmp(p, "json") == 0)
result_type = JSONOID;
else
result_type = TEXTOID;
/* don't "break", as ExplainQuery will use the last value */
}
}
/* Need a tuple descriptor representing a single TEXT or XML column */
tupdesc = CreateTemplateTupleDesc(1, false);
TupleDescInitEntry(tupdesc, (AttrNumber) 1, "QUERY PLAN",
result_type, -1, 0);
return tupdesc;
}
/*
* ExplainOneQuery -
* print out the execution plan for one Query
*
* "into" is NULL unless we are explaining the contents of a CreateTableAsStmt.
*/
static void
Change representation of statement lists, and add statement location info. This patch makes several changes that improve the consistency of representation of lists of statements. It's always been the case that the output of parse analysis is a list of Query nodes, whatever the types of the individual statements in the list. This patch brings similar consistency to the outputs of raw parsing and planning steps: * The output of raw parsing is now always a list of RawStmt nodes; the statement-type-dependent nodes are one level down from that. * The output of pg_plan_queries() is now always a list of PlannedStmt nodes, even for utility statements. In the case of a utility statement, "planning" just consists of wrapping a CMD_UTILITY PlannedStmt around the utility node. This list representation is now used in Portal and CachedPlan plan lists, replacing the former convention of intermixing PlannedStmts with bare utility-statement nodes. Now, every list of statements has a consistent head-node type depending on how far along it is in processing. This allows changing many places that formerly used generic "Node *" pointers to use a more specific pointer type, thus reducing the number of IsA() tests and casts needed, as well as improving code clarity. Also, the post-parse-analysis representation of DECLARE CURSOR is changed so that it looks more like EXPLAIN, PREPARE, etc. That is, the contained SELECT remains a child of the DeclareCursorStmt rather than getting flipped around to be the other way. It's now true for both Query and PlannedStmt that utilityStmt is non-null if and only if commandType is CMD_UTILITY. That allows simplifying a lot of places that were testing both fields. (I think some of those were just defensive programming, but in many places, it was actually necessary to avoid confusing DECLARE CURSOR with SELECT.) Because PlannedStmt carries a canSetTag field, we're also able to get rid of some ad-hoc rules about how to reconstruct canSetTag for a bare utility statement; specifically, the assumption that a utility is canSetTag if and only if it's the only one in its list. While I see no near-term need for relaxing that restriction, it's nice to get rid of the ad-hocery. The API of ProcessUtility() is changed so that what it's passed is the wrapper PlannedStmt not just the bare utility statement. This will affect all users of ProcessUtility_hook, but the changes are pretty trivial; see the affected contrib modules for examples of the minimum change needed. (Most compilers should give pointer-type-mismatch warnings for uncorrected code.) There's also a change in the API of ExplainOneQuery_hook, to pass through cursorOptions instead of expecting hook functions to know what to pick. This is needed because of the DECLARE CURSOR changes, but really should have been done in 9.6; it's unlikely that any extant hook functions know about using CURSOR_OPT_PARALLEL_OK. Finally, teach gram.y to save statement boundary locations in RawStmt nodes, and pass those through to Query and PlannedStmt nodes. This allows more intelligent handling of cases where a source query string contains multiple statements. This patch doesn't actually do anything with the information, but a follow-on patch will. (Passing this information through cleanly is the true motivation for these changes; while I think this is all good cleanup, it's unlikely we'd have bothered without this end goal.) catversion bump because addition of location fields to struct Query affects stored rules. This patch is by me, but it owes a good deal to Fabien Coelho who did a lot of preliminary work on the problem, and also reviewed the patch. Discussion: https://postgr.es/m/alpine.DEB.2.20.1612200926310.29821@lancre
2017-01-14 22:02:35 +01:00
ExplainOneQuery(Query *query, int cursorOptions,
IntoClause *into, ExplainState *es,
const char *queryString, ParamListInfo params,
QueryEnvironment *queryEnv)
{
/* planner will not cope with utility statements */
if (query->commandType == CMD_UTILITY)
{
ExplainOneUtility(query->utilityStmt, into, es, queryString, params,
queryEnv);
return;
}
/* if an advisor plugin is present, let it manage things */
if (ExplainOneQuery_hook)
Change representation of statement lists, and add statement location info. This patch makes several changes that improve the consistency of representation of lists of statements. It's always been the case that the output of parse analysis is a list of Query nodes, whatever the types of the individual statements in the list. This patch brings similar consistency to the outputs of raw parsing and planning steps: * The output of raw parsing is now always a list of RawStmt nodes; the statement-type-dependent nodes are one level down from that. * The output of pg_plan_queries() is now always a list of PlannedStmt nodes, even for utility statements. In the case of a utility statement, "planning" just consists of wrapping a CMD_UTILITY PlannedStmt around the utility node. This list representation is now used in Portal and CachedPlan plan lists, replacing the former convention of intermixing PlannedStmts with bare utility-statement nodes. Now, every list of statements has a consistent head-node type depending on how far along it is in processing. This allows changing many places that formerly used generic "Node *" pointers to use a more specific pointer type, thus reducing the number of IsA() tests and casts needed, as well as improving code clarity. Also, the post-parse-analysis representation of DECLARE CURSOR is changed so that it looks more like EXPLAIN, PREPARE, etc. That is, the contained SELECT remains a child of the DeclareCursorStmt rather than getting flipped around to be the other way. It's now true for both Query and PlannedStmt that utilityStmt is non-null if and only if commandType is CMD_UTILITY. That allows simplifying a lot of places that were testing both fields. (I think some of those were just defensive programming, but in many places, it was actually necessary to avoid confusing DECLARE CURSOR with SELECT.) Because PlannedStmt carries a canSetTag field, we're also able to get rid of some ad-hoc rules about how to reconstruct canSetTag for a bare utility statement; specifically, the assumption that a utility is canSetTag if and only if it's the only one in its list. While I see no near-term need for relaxing that restriction, it's nice to get rid of the ad-hocery. The API of ProcessUtility() is changed so that what it's passed is the wrapper PlannedStmt not just the bare utility statement. This will affect all users of ProcessUtility_hook, but the changes are pretty trivial; see the affected contrib modules for examples of the minimum change needed. (Most compilers should give pointer-type-mismatch warnings for uncorrected code.) There's also a change in the API of ExplainOneQuery_hook, to pass through cursorOptions instead of expecting hook functions to know what to pick. This is needed because of the DECLARE CURSOR changes, but really should have been done in 9.6; it's unlikely that any extant hook functions know about using CURSOR_OPT_PARALLEL_OK. Finally, teach gram.y to save statement boundary locations in RawStmt nodes, and pass those through to Query and PlannedStmt nodes. This allows more intelligent handling of cases where a source query string contains multiple statements. This patch doesn't actually do anything with the information, but a follow-on patch will. (Passing this information through cleanly is the true motivation for these changes; while I think this is all good cleanup, it's unlikely we'd have bothered without this end goal.) catversion bump because addition of location fields to struct Query affects stored rules. This patch is by me, but it owes a good deal to Fabien Coelho who did a lot of preliminary work on the problem, and also reviewed the patch. Discussion: https://postgr.es/m/alpine.DEB.2.20.1612200926310.29821@lancre
2017-01-14 22:02:35 +01:00
(*ExplainOneQuery_hook) (query, cursorOptions, into, es,
queryString, params);
else
{
PlannedStmt *plan;
instr_time planstart,
planduration;
INSTR_TIME_SET_CURRENT(planstart);
/* plan the query */
Change representation of statement lists, and add statement location info. This patch makes several changes that improve the consistency of representation of lists of statements. It's always been the case that the output of parse analysis is a list of Query nodes, whatever the types of the individual statements in the list. This patch brings similar consistency to the outputs of raw parsing and planning steps: * The output of raw parsing is now always a list of RawStmt nodes; the statement-type-dependent nodes are one level down from that. * The output of pg_plan_queries() is now always a list of PlannedStmt nodes, even for utility statements. In the case of a utility statement, "planning" just consists of wrapping a CMD_UTILITY PlannedStmt around the utility node. This list representation is now used in Portal and CachedPlan plan lists, replacing the former convention of intermixing PlannedStmts with bare utility-statement nodes. Now, every list of statements has a consistent head-node type depending on how far along it is in processing. This allows changing many places that formerly used generic "Node *" pointers to use a more specific pointer type, thus reducing the number of IsA() tests and casts needed, as well as improving code clarity. Also, the post-parse-analysis representation of DECLARE CURSOR is changed so that it looks more like EXPLAIN, PREPARE, etc. That is, the contained SELECT remains a child of the DeclareCursorStmt rather than getting flipped around to be the other way. It's now true for both Query and PlannedStmt that utilityStmt is non-null if and only if commandType is CMD_UTILITY. That allows simplifying a lot of places that were testing both fields. (I think some of those were just defensive programming, but in many places, it was actually necessary to avoid confusing DECLARE CURSOR with SELECT.) Because PlannedStmt carries a canSetTag field, we're also able to get rid of some ad-hoc rules about how to reconstruct canSetTag for a bare utility statement; specifically, the assumption that a utility is canSetTag if and only if it's the only one in its list. While I see no near-term need for relaxing that restriction, it's nice to get rid of the ad-hocery. The API of ProcessUtility() is changed so that what it's passed is the wrapper PlannedStmt not just the bare utility statement. This will affect all users of ProcessUtility_hook, but the changes are pretty trivial; see the affected contrib modules for examples of the minimum change needed. (Most compilers should give pointer-type-mismatch warnings for uncorrected code.) There's also a change in the API of ExplainOneQuery_hook, to pass through cursorOptions instead of expecting hook functions to know what to pick. This is needed because of the DECLARE CURSOR changes, but really should have been done in 9.6; it's unlikely that any extant hook functions know about using CURSOR_OPT_PARALLEL_OK. Finally, teach gram.y to save statement boundary locations in RawStmt nodes, and pass those through to Query and PlannedStmt nodes. This allows more intelligent handling of cases where a source query string contains multiple statements. This patch doesn't actually do anything with the information, but a follow-on patch will. (Passing this information through cleanly is the true motivation for these changes; while I think this is all good cleanup, it's unlikely we'd have bothered without this end goal.) catversion bump because addition of location fields to struct Query affects stored rules. This patch is by me, but it owes a good deal to Fabien Coelho who did a lot of preliminary work on the problem, and also reviewed the patch. Discussion: https://postgr.es/m/alpine.DEB.2.20.1612200926310.29821@lancre
2017-01-14 22:02:35 +01:00
plan = pg_plan_query(query, cursorOptions, params);
INSTR_TIME_SET_CURRENT(planduration);
INSTR_TIME_SUBTRACT(planduration, planstart);
/* run it (if needed) and produce output */
ExplainOnePlan(plan, into, es, queryString, params, queryEnv,
&planduration);
}
}
/*
* ExplainOneUtility -
* print out the execution plan for one utility statement
* (In general, utility statements don't have plans, but there are some
* we treat as special cases)
*
* "into" is NULL unless we are explaining the contents of a CreateTableAsStmt.
*
* This is exported because it's called back from prepare.c in the
* EXPLAIN EXECUTE case.
*/
void
ExplainOneUtility(Node *utilityStmt, IntoClause *into, ExplainState *es,
const char *queryString, ParamListInfo params,
QueryEnvironment *queryEnv)
{
if (utilityStmt == NULL)
return;
if (IsA(utilityStmt, CreateTableAsStmt))
{
/*
* We have to rewrite the contained SELECT and then pass it back to
* ExplainOneQuery. It's probably not really necessary to copy the
* contained parsetree another time, but let's be safe.
Change representation of statement lists, and add statement location info. This patch makes several changes that improve the consistency of representation of lists of statements. It's always been the case that the output of parse analysis is a list of Query nodes, whatever the types of the individual statements in the list. This patch brings similar consistency to the outputs of raw parsing and planning steps: * The output of raw parsing is now always a list of RawStmt nodes; the statement-type-dependent nodes are one level down from that. * The output of pg_plan_queries() is now always a list of PlannedStmt nodes, even for utility statements. In the case of a utility statement, "planning" just consists of wrapping a CMD_UTILITY PlannedStmt around the utility node. This list representation is now used in Portal and CachedPlan plan lists, replacing the former convention of intermixing PlannedStmts with bare utility-statement nodes. Now, every list of statements has a consistent head-node type depending on how far along it is in processing. This allows changing many places that formerly used generic "Node *" pointers to use a more specific pointer type, thus reducing the number of IsA() tests and casts needed, as well as improving code clarity. Also, the post-parse-analysis representation of DECLARE CURSOR is changed so that it looks more like EXPLAIN, PREPARE, etc. That is, the contained SELECT remains a child of the DeclareCursorStmt rather than getting flipped around to be the other way. It's now true for both Query and PlannedStmt that utilityStmt is non-null if and only if commandType is CMD_UTILITY. That allows simplifying a lot of places that were testing both fields. (I think some of those were just defensive programming, but in many places, it was actually necessary to avoid confusing DECLARE CURSOR with SELECT.) Because PlannedStmt carries a canSetTag field, we're also able to get rid of some ad-hoc rules about how to reconstruct canSetTag for a bare utility statement; specifically, the assumption that a utility is canSetTag if and only if it's the only one in its list. While I see no near-term need for relaxing that restriction, it's nice to get rid of the ad-hocery. The API of ProcessUtility() is changed so that what it's passed is the wrapper PlannedStmt not just the bare utility statement. This will affect all users of ProcessUtility_hook, but the changes are pretty trivial; see the affected contrib modules for examples of the minimum change needed. (Most compilers should give pointer-type-mismatch warnings for uncorrected code.) There's also a change in the API of ExplainOneQuery_hook, to pass through cursorOptions instead of expecting hook functions to know what to pick. This is needed because of the DECLARE CURSOR changes, but really should have been done in 9.6; it's unlikely that any extant hook functions know about using CURSOR_OPT_PARALLEL_OK. Finally, teach gram.y to save statement boundary locations in RawStmt nodes, and pass those through to Query and PlannedStmt nodes. This allows more intelligent handling of cases where a source query string contains multiple statements. This patch doesn't actually do anything with the information, but a follow-on patch will. (Passing this information through cleanly is the true motivation for these changes; while I think this is all good cleanup, it's unlikely we'd have bothered without this end goal.) catversion bump because addition of location fields to struct Query affects stored rules. This patch is by me, but it owes a good deal to Fabien Coelho who did a lot of preliminary work on the problem, and also reviewed the patch. Discussion: https://postgr.es/m/alpine.DEB.2.20.1612200926310.29821@lancre
2017-01-14 22:02:35 +01:00
*
* Like ExecCreateTableAs, disallow parallelism in the plan.
*/
CreateTableAsStmt *ctas = (CreateTableAsStmt *) utilityStmt;
List *rewritten;
rewritten = QueryRewrite(castNode(Query, copyObject(ctas->query)));
Assert(list_length(rewritten) == 1);
ExplainOneQuery(linitial_node(Query, rewritten),
Change representation of statement lists, and add statement location info. This patch makes several changes that improve the consistency of representation of lists of statements. It's always been the case that the output of parse analysis is a list of Query nodes, whatever the types of the individual statements in the list. This patch brings similar consistency to the outputs of raw parsing and planning steps: * The output of raw parsing is now always a list of RawStmt nodes; the statement-type-dependent nodes are one level down from that. * The output of pg_plan_queries() is now always a list of PlannedStmt nodes, even for utility statements. In the case of a utility statement, "planning" just consists of wrapping a CMD_UTILITY PlannedStmt around the utility node. This list representation is now used in Portal and CachedPlan plan lists, replacing the former convention of intermixing PlannedStmts with bare utility-statement nodes. Now, every list of statements has a consistent head-node type depending on how far along it is in processing. This allows changing many places that formerly used generic "Node *" pointers to use a more specific pointer type, thus reducing the number of IsA() tests and casts needed, as well as improving code clarity. Also, the post-parse-analysis representation of DECLARE CURSOR is changed so that it looks more like EXPLAIN, PREPARE, etc. That is, the contained SELECT remains a child of the DeclareCursorStmt rather than getting flipped around to be the other way. It's now true for both Query and PlannedStmt that utilityStmt is non-null if and only if commandType is CMD_UTILITY. That allows simplifying a lot of places that were testing both fields. (I think some of those were just defensive programming, but in many places, it was actually necessary to avoid confusing DECLARE CURSOR with SELECT.) Because PlannedStmt carries a canSetTag field, we're also able to get rid of some ad-hoc rules about how to reconstruct canSetTag for a bare utility statement; specifically, the assumption that a utility is canSetTag if and only if it's the only one in its list. While I see no near-term need for relaxing that restriction, it's nice to get rid of the ad-hocery. The API of ProcessUtility() is changed so that what it's passed is the wrapper PlannedStmt not just the bare utility statement. This will affect all users of ProcessUtility_hook, but the changes are pretty trivial; see the affected contrib modules for examples of the minimum change needed. (Most compilers should give pointer-type-mismatch warnings for uncorrected code.) There's also a change in the API of ExplainOneQuery_hook, to pass through cursorOptions instead of expecting hook functions to know what to pick. This is needed because of the DECLARE CURSOR changes, but really should have been done in 9.6; it's unlikely that any extant hook functions know about using CURSOR_OPT_PARALLEL_OK. Finally, teach gram.y to save statement boundary locations in RawStmt nodes, and pass those through to Query and PlannedStmt nodes. This allows more intelligent handling of cases where a source query string contains multiple statements. This patch doesn't actually do anything with the information, but a follow-on patch will. (Passing this information through cleanly is the true motivation for these changes; while I think this is all good cleanup, it's unlikely we'd have bothered without this end goal.) catversion bump because addition of location fields to struct Query affects stored rules. This patch is by me, but it owes a good deal to Fabien Coelho who did a lot of preliminary work on the problem, and also reviewed the patch. Discussion: https://postgr.es/m/alpine.DEB.2.20.1612200926310.29821@lancre
2017-01-14 22:02:35 +01:00
0, ctas->into, es,
queryString, params, queryEnv);
Change representation of statement lists, and add statement location info. This patch makes several changes that improve the consistency of representation of lists of statements. It's always been the case that the output of parse analysis is a list of Query nodes, whatever the types of the individual statements in the list. This patch brings similar consistency to the outputs of raw parsing and planning steps: * The output of raw parsing is now always a list of RawStmt nodes; the statement-type-dependent nodes are one level down from that. * The output of pg_plan_queries() is now always a list of PlannedStmt nodes, even for utility statements. In the case of a utility statement, "planning" just consists of wrapping a CMD_UTILITY PlannedStmt around the utility node. This list representation is now used in Portal and CachedPlan plan lists, replacing the former convention of intermixing PlannedStmts with bare utility-statement nodes. Now, every list of statements has a consistent head-node type depending on how far along it is in processing. This allows changing many places that formerly used generic "Node *" pointers to use a more specific pointer type, thus reducing the number of IsA() tests and casts needed, as well as improving code clarity. Also, the post-parse-analysis representation of DECLARE CURSOR is changed so that it looks more like EXPLAIN, PREPARE, etc. That is, the contained SELECT remains a child of the DeclareCursorStmt rather than getting flipped around to be the other way. It's now true for both Query and PlannedStmt that utilityStmt is non-null if and only if commandType is CMD_UTILITY. That allows simplifying a lot of places that were testing both fields. (I think some of those were just defensive programming, but in many places, it was actually necessary to avoid confusing DECLARE CURSOR with SELECT.) Because PlannedStmt carries a canSetTag field, we're also able to get rid of some ad-hoc rules about how to reconstruct canSetTag for a bare utility statement; specifically, the assumption that a utility is canSetTag if and only if it's the only one in its list. While I see no near-term need for relaxing that restriction, it's nice to get rid of the ad-hocery. The API of ProcessUtility() is changed so that what it's passed is the wrapper PlannedStmt not just the bare utility statement. This will affect all users of ProcessUtility_hook, but the changes are pretty trivial; see the affected contrib modules for examples of the minimum change needed. (Most compilers should give pointer-type-mismatch warnings for uncorrected code.) There's also a change in the API of ExplainOneQuery_hook, to pass through cursorOptions instead of expecting hook functions to know what to pick. This is needed because of the DECLARE CURSOR changes, but really should have been done in 9.6; it's unlikely that any extant hook functions know about using CURSOR_OPT_PARALLEL_OK. Finally, teach gram.y to save statement boundary locations in RawStmt nodes, and pass those through to Query and PlannedStmt nodes. This allows more intelligent handling of cases where a source query string contains multiple statements. This patch doesn't actually do anything with the information, but a follow-on patch will. (Passing this information through cleanly is the true motivation for these changes; while I think this is all good cleanup, it's unlikely we'd have bothered without this end goal.) catversion bump because addition of location fields to struct Query affects stored rules. This patch is by me, but it owes a good deal to Fabien Coelho who did a lot of preliminary work on the problem, and also reviewed the patch. Discussion: https://postgr.es/m/alpine.DEB.2.20.1612200926310.29821@lancre
2017-01-14 22:02:35 +01:00
}
else if (IsA(utilityStmt, DeclareCursorStmt))
{
/*
* Likewise for DECLARE CURSOR.
*
* Notice that if you say EXPLAIN ANALYZE DECLARE CURSOR then we'll
* actually run the query. This is different from pre-8.3 behavior
* but seems more useful than not running the query. No cursor will
* be created, however.
*/
DeclareCursorStmt *dcs = (DeclareCursorStmt *) utilityStmt;
List *rewritten;
rewritten = QueryRewrite(castNode(Query, copyObject(dcs->query)));
Change representation of statement lists, and add statement location info. This patch makes several changes that improve the consistency of representation of lists of statements. It's always been the case that the output of parse analysis is a list of Query nodes, whatever the types of the individual statements in the list. This patch brings similar consistency to the outputs of raw parsing and planning steps: * The output of raw parsing is now always a list of RawStmt nodes; the statement-type-dependent nodes are one level down from that. * The output of pg_plan_queries() is now always a list of PlannedStmt nodes, even for utility statements. In the case of a utility statement, "planning" just consists of wrapping a CMD_UTILITY PlannedStmt around the utility node. This list representation is now used in Portal and CachedPlan plan lists, replacing the former convention of intermixing PlannedStmts with bare utility-statement nodes. Now, every list of statements has a consistent head-node type depending on how far along it is in processing. This allows changing many places that formerly used generic "Node *" pointers to use a more specific pointer type, thus reducing the number of IsA() tests and casts needed, as well as improving code clarity. Also, the post-parse-analysis representation of DECLARE CURSOR is changed so that it looks more like EXPLAIN, PREPARE, etc. That is, the contained SELECT remains a child of the DeclareCursorStmt rather than getting flipped around to be the other way. It's now true for both Query and PlannedStmt that utilityStmt is non-null if and only if commandType is CMD_UTILITY. That allows simplifying a lot of places that were testing both fields. (I think some of those were just defensive programming, but in many places, it was actually necessary to avoid confusing DECLARE CURSOR with SELECT.) Because PlannedStmt carries a canSetTag field, we're also able to get rid of some ad-hoc rules about how to reconstruct canSetTag for a bare utility statement; specifically, the assumption that a utility is canSetTag if and only if it's the only one in its list. While I see no near-term need for relaxing that restriction, it's nice to get rid of the ad-hocery. The API of ProcessUtility() is changed so that what it's passed is the wrapper PlannedStmt not just the bare utility statement. This will affect all users of ProcessUtility_hook, but the changes are pretty trivial; see the affected contrib modules for examples of the minimum change needed. (Most compilers should give pointer-type-mismatch warnings for uncorrected code.) There's also a change in the API of ExplainOneQuery_hook, to pass through cursorOptions instead of expecting hook functions to know what to pick. This is needed because of the DECLARE CURSOR changes, but really should have been done in 9.6; it's unlikely that any extant hook functions know about using CURSOR_OPT_PARALLEL_OK. Finally, teach gram.y to save statement boundary locations in RawStmt nodes, and pass those through to Query and PlannedStmt nodes. This allows more intelligent handling of cases where a source query string contains multiple statements. This patch doesn't actually do anything with the information, but a follow-on patch will. (Passing this information through cleanly is the true motivation for these changes; while I think this is all good cleanup, it's unlikely we'd have bothered without this end goal.) catversion bump because addition of location fields to struct Query affects stored rules. This patch is by me, but it owes a good deal to Fabien Coelho who did a lot of preliminary work on the problem, and also reviewed the patch. Discussion: https://postgr.es/m/alpine.DEB.2.20.1612200926310.29821@lancre
2017-01-14 22:02:35 +01:00
Assert(list_length(rewritten) == 1);
ExplainOneQuery(linitial_node(Query, rewritten),
Change representation of statement lists, and add statement location info. This patch makes several changes that improve the consistency of representation of lists of statements. It's always been the case that the output of parse analysis is a list of Query nodes, whatever the types of the individual statements in the list. This patch brings similar consistency to the outputs of raw parsing and planning steps: * The output of raw parsing is now always a list of RawStmt nodes; the statement-type-dependent nodes are one level down from that. * The output of pg_plan_queries() is now always a list of PlannedStmt nodes, even for utility statements. In the case of a utility statement, "planning" just consists of wrapping a CMD_UTILITY PlannedStmt around the utility node. This list representation is now used in Portal and CachedPlan plan lists, replacing the former convention of intermixing PlannedStmts with bare utility-statement nodes. Now, every list of statements has a consistent head-node type depending on how far along it is in processing. This allows changing many places that formerly used generic "Node *" pointers to use a more specific pointer type, thus reducing the number of IsA() tests and casts needed, as well as improving code clarity. Also, the post-parse-analysis representation of DECLARE CURSOR is changed so that it looks more like EXPLAIN, PREPARE, etc. That is, the contained SELECT remains a child of the DeclareCursorStmt rather than getting flipped around to be the other way. It's now true for both Query and PlannedStmt that utilityStmt is non-null if and only if commandType is CMD_UTILITY. That allows simplifying a lot of places that were testing both fields. (I think some of those were just defensive programming, but in many places, it was actually necessary to avoid confusing DECLARE CURSOR with SELECT.) Because PlannedStmt carries a canSetTag field, we're also able to get rid of some ad-hoc rules about how to reconstruct canSetTag for a bare utility statement; specifically, the assumption that a utility is canSetTag if and only if it's the only one in its list. While I see no near-term need for relaxing that restriction, it's nice to get rid of the ad-hocery. The API of ProcessUtility() is changed so that what it's passed is the wrapper PlannedStmt not just the bare utility statement. This will affect all users of ProcessUtility_hook, but the changes are pretty trivial; see the affected contrib modules for examples of the minimum change needed. (Most compilers should give pointer-type-mismatch warnings for uncorrected code.) There's also a change in the API of ExplainOneQuery_hook, to pass through cursorOptions instead of expecting hook functions to know what to pick. This is needed because of the DECLARE CURSOR changes, but really should have been done in 9.6; it's unlikely that any extant hook functions know about using CURSOR_OPT_PARALLEL_OK. Finally, teach gram.y to save statement boundary locations in RawStmt nodes, and pass those through to Query and PlannedStmt nodes. This allows more intelligent handling of cases where a source query string contains multiple statements. This patch doesn't actually do anything with the information, but a follow-on patch will. (Passing this information through cleanly is the true motivation for these changes; while I think this is all good cleanup, it's unlikely we'd have bothered without this end goal.) catversion bump because addition of location fields to struct Query affects stored rules. This patch is by me, but it owes a good deal to Fabien Coelho who did a lot of preliminary work on the problem, and also reviewed the patch. Discussion: https://postgr.es/m/alpine.DEB.2.20.1612200926310.29821@lancre
2017-01-14 22:02:35 +01:00
dcs->options, NULL, es,
queryString, params, queryEnv);
}
else if (IsA(utilityStmt, ExecuteStmt))
ExplainExecuteQuery((ExecuteStmt *) utilityStmt, into, es,
queryString, params, queryEnv);
else if (IsA(utilityStmt, NotifyStmt))
{
if (es->format == EXPLAIN_FORMAT_TEXT)
appendStringInfoString(es->str, "NOTIFY\n");
else
ExplainDummyGroup("Notify", NULL, es);
}
else
{
if (es->format == EXPLAIN_FORMAT_TEXT)
appendStringInfoString(es->str,
"Utility statements have no plan structure\n");
else
ExplainDummyGroup("Utility Statement", NULL, es);
}
}
/*
* ExplainOnePlan -
* given a planned query, execute it if needed, and then print
* EXPLAIN output
*
* "into" is NULL unless we are explaining the contents of a CreateTableAsStmt,
* in which case executing the query should result in creating that table.
*
* This is exported because it's called back from prepare.c in the
* EXPLAIN EXECUTE case, and because an index advisor plugin would need
* to call it.
*/
void
ExplainOnePlan(PlannedStmt *plannedstmt, IntoClause *into, ExplainState *es,
const char *queryString, ParamListInfo params,
QueryEnvironment *queryEnv, const instr_time *planduration)
{
DestReceiver *dest;
QueryDesc *queryDesc;
2005-10-15 04:49:52 +02:00
instr_time starttime;
double totaltime = 0;
int eflags;
int instrument_option = 0;
Change representation of statement lists, and add statement location info. This patch makes several changes that improve the consistency of representation of lists of statements. It's always been the case that the output of parse analysis is a list of Query nodes, whatever the types of the individual statements in the list. This patch brings similar consistency to the outputs of raw parsing and planning steps: * The output of raw parsing is now always a list of RawStmt nodes; the statement-type-dependent nodes are one level down from that. * The output of pg_plan_queries() is now always a list of PlannedStmt nodes, even for utility statements. In the case of a utility statement, "planning" just consists of wrapping a CMD_UTILITY PlannedStmt around the utility node. This list representation is now used in Portal and CachedPlan plan lists, replacing the former convention of intermixing PlannedStmts with bare utility-statement nodes. Now, every list of statements has a consistent head-node type depending on how far along it is in processing. This allows changing many places that formerly used generic "Node *" pointers to use a more specific pointer type, thus reducing the number of IsA() tests and casts needed, as well as improving code clarity. Also, the post-parse-analysis representation of DECLARE CURSOR is changed so that it looks more like EXPLAIN, PREPARE, etc. That is, the contained SELECT remains a child of the DeclareCursorStmt rather than getting flipped around to be the other way. It's now true for both Query and PlannedStmt that utilityStmt is non-null if and only if commandType is CMD_UTILITY. That allows simplifying a lot of places that were testing both fields. (I think some of those were just defensive programming, but in many places, it was actually necessary to avoid confusing DECLARE CURSOR with SELECT.) Because PlannedStmt carries a canSetTag field, we're also able to get rid of some ad-hoc rules about how to reconstruct canSetTag for a bare utility statement; specifically, the assumption that a utility is canSetTag if and only if it's the only one in its list. While I see no near-term need for relaxing that restriction, it's nice to get rid of the ad-hocery. The API of ProcessUtility() is changed so that what it's passed is the wrapper PlannedStmt not just the bare utility statement. This will affect all users of ProcessUtility_hook, but the changes are pretty trivial; see the affected contrib modules for examples of the minimum change needed. (Most compilers should give pointer-type-mismatch warnings for uncorrected code.) There's also a change in the API of ExplainOneQuery_hook, to pass through cursorOptions instead of expecting hook functions to know what to pick. This is needed because of the DECLARE CURSOR changes, but really should have been done in 9.6; it's unlikely that any extant hook functions know about using CURSOR_OPT_PARALLEL_OK. Finally, teach gram.y to save statement boundary locations in RawStmt nodes, and pass those through to Query and PlannedStmt nodes. This allows more intelligent handling of cases where a source query string contains multiple statements. This patch doesn't actually do anything with the information, but a follow-on patch will. (Passing this information through cleanly is the true motivation for these changes; while I think this is all good cleanup, it's unlikely we'd have bothered without this end goal.) catversion bump because addition of location fields to struct Query affects stored rules. This patch is by me, but it owes a good deal to Fabien Coelho who did a lot of preliminary work on the problem, and also reviewed the patch. Discussion: https://postgr.es/m/alpine.DEB.2.20.1612200926310.29821@lancre
2017-01-14 22:02:35 +01:00
Assert(plannedstmt->commandType != CMD_UTILITY);
if (es->analyze && es->timing)
instrument_option |= INSTRUMENT_TIMER;
else if (es->analyze)
instrument_option |= INSTRUMENT_ROWS;
if (es->buffers)
instrument_option |= INSTRUMENT_BUFFERS;
/*
* We always collect timing for the entire statement, even when node-level
* timing is off, so we don't look at es->timing here. (We could skip
* this if !es->summary, but it's hardly worth the complication.)
*/
INSTR_TIME_SET_CURRENT(starttime);
/*
* Use a snapshot with an updated command ID to ensure this query sees
* results of any previously executed queries.
*/
PushCopiedSnapshot(GetActiveSnapshot());
UpdateActiveSnapshotCommandId();
/*
* Normally we discard the query's output, but if explaining CREATE TABLE
* AS, we'd better use the appropriate tuple receiver.
*/
if (into)
dest = CreateIntoRelDestReceiver(into);
else
dest = None_Receiver;
/* Create a QueryDesc for the query */
queryDesc = CreateQueryDesc(plannedstmt, queryString,
GetActiveSnapshot(), InvalidSnapshot,
dest, params, queryEnv, instrument_option);
/* Select execution options */
if (es->analyze)
eflags = 0; /* default run-to-completion flags */
else
eflags = EXEC_FLAG_EXPLAIN_ONLY;
if (into)
eflags |= GetIntoRelEFlags(into);
/* call ExecutorStart to prepare the plan for execution */
ExecutorStart(queryDesc, eflags);
/* Execute the plan for statistics if asked for */
if (es->analyze)
{
ScanDirection dir;
/* EXPLAIN ANALYZE CREATE TABLE AS WITH NO DATA is weird */
if (into && into->skipData)
dir = NoMovementScanDirection;
else
dir = ForwardScanDirection;
/* run the plan */
2017-03-23 18:05:48 +01:00
ExecutorRun(queryDesc, dir, 0L, true);
/* run cleanup too */
ExecutorFinish(queryDesc);
/* We can't run ExecutorEnd 'till we're done printing the stats... */
totaltime += elapsed_time(&starttime);
}
ExplainOpenGroup("Query", NULL, true, es);
/* Create textual dump of plan tree */
ExplainPrintPlan(es, queryDesc);
if (es->summary && planduration)
{
double plantime = INSTR_TIME_GET_DOUBLE(*planduration);
if (es->format == EXPLAIN_FORMAT_TEXT)
appendStringInfo(es->str, "Planning time: %.3f ms\n",
1000.0 * plantime);
else
ExplainPropertyFloat("Planning Time", 1000.0 * plantime, 3, es);
}
/* Print info about runtime of triggers */
if (es->analyze)
ExplainPrintTriggers(es, queryDesc);
/*
2005-10-15 04:49:52 +02:00
* Close down the query and free resources. Include time for this in the
* total execution time (although it should be pretty minimal).
*/
INSTR_TIME_SET_CURRENT(starttime);
ExecutorEnd(queryDesc);
FreeQueryDesc(queryDesc);
PopActiveSnapshot();
/* We need a CCI just in case query expanded to multiple plans */
if (es->analyze)
CommandCounterIncrement();
totaltime += elapsed_time(&starttime);
/*
* We only report execution time if we actually ran the query (that is,
* the user specified ANALYZE), and if summary reporting is enabled (the
* user can set SUMMARY OFF to not have the timing information included in
* the output). By default, ANALYZE sets SUMMARY to true.
*/
if (es->summary && es->analyze)
{
if (es->format == EXPLAIN_FORMAT_TEXT)
appendStringInfo(es->str, "Execution time: %.3f ms\n",
1000.0 * totaltime);
else
ExplainPropertyFloat("Execution Time", 1000.0 * totaltime,
3, es);
}
ExplainCloseGroup("Query", NULL, true, es);
}
/*
* ExplainPrintPlan -
* convert a QueryDesc's plan tree to text and append it to es->str
*
* The caller should have set up the options fields of *es, as well as
Print a given subplan only once in EXPLAIN. We have, for a very long time, allowed the same subplan (same member of the PlannedStmt.subplans list) to be referenced by more than one SubPlan node; this avoids problems for cases such as subplans within an IndexScan's indxqual and indxqualorig fields. However, EXPLAIN had not gotten the memo and would print each reference as though it were an independent identical subplan. To fix, track plan_ids of subplans we've printed and don't print the same plan_id twice. Per report from Pavel Stehule. BTW: the particular case of IndexScan didn't cause visible duplication in a plain EXPLAIN, only EXPLAIN ANALYZE, because in the former case we short-circuit executor startup before the indxqual field is processed by ExecInitExpr. That seems like it could easily lead to other EXPLAIN problems in future, but it's not clear how to avoid it without breaking the "EXPLAIN a plan using hypothetical indexes" use-case. For now I've left that issue alone. Although this is a longstanding bug, it's purely cosmetic (no great harm is done by the repeat printout) and we haven't had field complaints before. So I'm hesitant to back-patch it, especially since there is some small risk of ABI problems due to the need to add a new field to ExplainState. In passing, rearrange order of fields in ExplainState to be less random, and update some obsolete comments about when/where to initialize them. Report: <CAFj8pRAimq+NK-menjt+3J4-LFoodDD8Or6=Lc_stcFD+eD4DA@mail.gmail.com>
2016-07-12 00:14:29 +02:00
* initializing the output buffer es->str. Also, output formatting state
* such as the indent level is assumed valid. Plan-tree-specific fields
* in *es are initialized here.
*
* NB: will not work on utility statements
*/
void
ExplainPrintPlan(ExplainState *es, QueryDesc *queryDesc)
{
Improve ruleutils.c's heuristics for dealing with rangetable aliases. The previous scheme had bugs in some corner cases involving tables that had been renamed since a view was made. This could result in dumped views that failed to reload or reloaded incorrectly, as seen in bug #7553 from Lloyd Albin, as well as in some pgsql-hackers discussion back in January. Also, its behavior for printing EXPLAIN plans was sometimes confusing because of willingness to use the same alias for multiple RTEs (it was Ashutosh Bapat's complaint about that aspect that started the January thread). To fix, ensure that each RTE in the query has a unique unqualified alias, by modifying the alias if necessary (we add "_" and digits as needed to create a non-conflicting name). Then we can just print its variables with that alias, avoiding the confusing and bug-prone scheme of sometimes schema-qualifying variable names. In EXPLAIN, it proves to be expedient to take the further step of only assigning such aliases to RTEs that are actually referenced in the query, since the planner has a habit of generating extra RTEs with the same alias in situations such as inheritance-tree expansion. Although this fixes a bug of very long standing, I'm hesitant to back-patch such a noticeable behavioral change. My experiments while creating a regression test convinced me that actually incorrect output (as opposed to confusing output) occurs only in very narrow cases, which is backed up by the lack of previous complaints from the field. So we may be better off living with it in released branches; and in any case it'd be smart to let this ripen awhile in HEAD before we consider back-patching it.
2012-09-22 01:03:10 +02:00
Bitmapset *rels_used = NULL;
PlanState *ps;
Improve ruleutils.c's heuristics for dealing with rangetable aliases. The previous scheme had bugs in some corner cases involving tables that had been renamed since a view was made. This could result in dumped views that failed to reload or reloaded incorrectly, as seen in bug #7553 from Lloyd Albin, as well as in some pgsql-hackers discussion back in January. Also, its behavior for printing EXPLAIN plans was sometimes confusing because of willingness to use the same alias for multiple RTEs (it was Ashutosh Bapat's complaint about that aspect that started the January thread). To fix, ensure that each RTE in the query has a unique unqualified alias, by modifying the alias if necessary (we add "_" and digits as needed to create a non-conflicting name). Then we can just print its variables with that alias, avoiding the confusing and bug-prone scheme of sometimes schema-qualifying variable names. In EXPLAIN, it proves to be expedient to take the further step of only assigning such aliases to RTEs that are actually referenced in the query, since the planner has a habit of generating extra RTEs with the same alias in situations such as inheritance-tree expansion. Although this fixes a bug of very long standing, I'm hesitant to back-patch such a noticeable behavioral change. My experiments while creating a regression test convinced me that actually incorrect output (as opposed to confusing output) occurs only in very narrow cases, which is backed up by the lack of previous complaints from the field. So we may be better off living with it in released branches; and in any case it'd be smart to let this ripen awhile in HEAD before we consider back-patching it.
2012-09-22 01:03:10 +02:00
Print a given subplan only once in EXPLAIN. We have, for a very long time, allowed the same subplan (same member of the PlannedStmt.subplans list) to be referenced by more than one SubPlan node; this avoids problems for cases such as subplans within an IndexScan's indxqual and indxqualorig fields. However, EXPLAIN had not gotten the memo and would print each reference as though it were an independent identical subplan. To fix, track plan_ids of subplans we've printed and don't print the same plan_id twice. Per report from Pavel Stehule. BTW: the particular case of IndexScan didn't cause visible duplication in a plain EXPLAIN, only EXPLAIN ANALYZE, because in the former case we short-circuit executor startup before the indxqual field is processed by ExecInitExpr. That seems like it could easily lead to other EXPLAIN problems in future, but it's not clear how to avoid it without breaking the "EXPLAIN a plan using hypothetical indexes" use-case. For now I've left that issue alone. Although this is a longstanding bug, it's purely cosmetic (no great harm is done by the repeat printout) and we haven't had field complaints before. So I'm hesitant to back-patch it, especially since there is some small risk of ABI problems due to the need to add a new field to ExplainState. In passing, rearrange order of fields in ExplainState to be less random, and update some obsolete comments about when/where to initialize them. Report: <CAFj8pRAimq+NK-menjt+3J4-LFoodDD8Or6=Lc_stcFD+eD4DA@mail.gmail.com>
2016-07-12 00:14:29 +02:00
/* Set up ExplainState fields associated with this plan tree */
Assert(queryDesc->plannedstmt != NULL);
es->pstmt = queryDesc->plannedstmt;
es->rtable = queryDesc->plannedstmt->rtable;
Improve ruleutils.c's heuristics for dealing with rangetable aliases. The previous scheme had bugs in some corner cases involving tables that had been renamed since a view was made. This could result in dumped views that failed to reload or reloaded incorrectly, as seen in bug #7553 from Lloyd Albin, as well as in some pgsql-hackers discussion back in January. Also, its behavior for printing EXPLAIN plans was sometimes confusing because of willingness to use the same alias for multiple RTEs (it was Ashutosh Bapat's complaint about that aspect that started the January thread). To fix, ensure that each RTE in the query has a unique unqualified alias, by modifying the alias if necessary (we add "_" and digits as needed to create a non-conflicting name). Then we can just print its variables with that alias, avoiding the confusing and bug-prone scheme of sometimes schema-qualifying variable names. In EXPLAIN, it proves to be expedient to take the further step of only assigning such aliases to RTEs that are actually referenced in the query, since the planner has a habit of generating extra RTEs with the same alias in situations such as inheritance-tree expansion. Although this fixes a bug of very long standing, I'm hesitant to back-patch such a noticeable behavioral change. My experiments while creating a regression test convinced me that actually incorrect output (as opposed to confusing output) occurs only in very narrow cases, which is backed up by the lack of previous complaints from the field. So we may be better off living with it in released branches; and in any case it'd be smart to let this ripen awhile in HEAD before we consider back-patching it.
2012-09-22 01:03:10 +02:00
ExplainPreScanNode(queryDesc->planstate, &rels_used);
es->rtable_names = select_rtable_names_for_explain(es->rtable, rels_used);
es->deparse_cxt = deparse_context_for_plan_rtable(es->rtable,
es->rtable_names);
Print a given subplan only once in EXPLAIN. We have, for a very long time, allowed the same subplan (same member of the PlannedStmt.subplans list) to be referenced by more than one SubPlan node; this avoids problems for cases such as subplans within an IndexScan's indxqual and indxqualorig fields. However, EXPLAIN had not gotten the memo and would print each reference as though it were an independent identical subplan. To fix, track plan_ids of subplans we've printed and don't print the same plan_id twice. Per report from Pavel Stehule. BTW: the particular case of IndexScan didn't cause visible duplication in a plain EXPLAIN, only EXPLAIN ANALYZE, because in the former case we short-circuit executor startup before the indxqual field is processed by ExecInitExpr. That seems like it could easily lead to other EXPLAIN problems in future, but it's not clear how to avoid it without breaking the "EXPLAIN a plan using hypothetical indexes" use-case. For now I've left that issue alone. Although this is a longstanding bug, it's purely cosmetic (no great harm is done by the repeat printout) and we haven't had field complaints before. So I'm hesitant to back-patch it, especially since there is some small risk of ABI problems due to the need to add a new field to ExplainState. In passing, rearrange order of fields in ExplainState to be less random, and update some obsolete comments about when/where to initialize them. Report: <CAFj8pRAimq+NK-menjt+3J4-LFoodDD8Or6=Lc_stcFD+eD4DA@mail.gmail.com>
2016-07-12 00:14:29 +02:00
es->printed_subplans = NULL;
/*
* Sometimes we mark a Gather node as "invisible", which means that it's
* not displayed in EXPLAIN output. The purpose of this is to allow
* running regression tests with force_parallel_mode=regress to get the
* same results as running the same tests with force_parallel_mode=off.
*/
ps = queryDesc->planstate;
if (IsA(ps, GatherState) &&((Gather *) ps->plan)->invisible)
ps = outerPlanState(ps);
ExplainNode(ps, NIL, NULL, NULL, es);
}
/*
* ExplainPrintTriggers -
* convert a QueryDesc's trigger statistics to text and append it to
* es->str
*
* The caller should have set up the options fields of *es, as well as
* initializing the output buffer es->str. Other fields in *es are
* initialized here.
*/
void
ExplainPrintTriggers(ExplainState *es, QueryDesc *queryDesc)
{
ResultRelInfo *rInfo;
bool show_relname;
int numrels = queryDesc->estate->es_num_result_relations;
int numrootrels = queryDesc->estate->es_num_root_result_relations;
List *leafrels = queryDesc->estate->es_leaf_result_relations;
List *targrels = queryDesc->estate->es_trig_target_relations;
int nr;
ListCell *l;
ExplainOpenGroup("Triggers", "Triggers", false, es);
show_relname = (numrels > 1 || numrootrels > 0 ||
leafrels != NIL || targrels != NIL);
rInfo = queryDesc->estate->es_result_relations;
for (nr = 0; nr < numrels; rInfo++, nr++)
report_triggers(rInfo, show_relname, es);
rInfo = queryDesc->estate->es_root_result_relations;
for (nr = 0; nr < numrootrels; rInfo++, nr++)
report_triggers(rInfo, show_relname, es);
foreach(l, leafrels)
{
rInfo = (ResultRelInfo *) lfirst(l);
report_triggers(rInfo, show_relname, es);
}
foreach(l, targrels)
{
rInfo = (ResultRelInfo *) lfirst(l);
report_triggers(rInfo, show_relname, es);
}
ExplainCloseGroup("Triggers", "Triggers", false, es);
}
/*
* ExplainQueryText -
2010-02-26 03:01:40 +01:00
* add a "Query Text" node that contains the actual text of the query
*
* The caller should have set up the options fields of *es, as well as
2010-02-26 03:01:40 +01:00
* initializing the output buffer es->str.
*
*/
void
ExplainQueryText(ExplainState *es, QueryDesc *queryDesc)
{
if (queryDesc->sourceText)
ExplainPropertyText("Query Text", queryDesc->sourceText, es);
}
/*
* report_triggers -
* report execution stats for a single relation's triggers
*/
static void
report_triggers(ResultRelInfo *rInfo, bool show_relname, ExplainState *es)
{
int nt;
if (!rInfo->ri_TrigDesc || !rInfo->ri_TrigInstrument)
return;
for (nt = 0; nt < rInfo->ri_TrigDesc->numtriggers; nt++)
{
Trigger *trig = rInfo->ri_TrigDesc->triggers + nt;
Instrumentation *instr = rInfo->ri_TrigInstrument + nt;
char *relname;
char *conname = NULL;
/* Must clean up instrumentation state */
InstrEndLoop(instr);
/*
2007-11-15 22:14:46 +01:00
* We ignore triggers that were never invoked; they likely aren't
* relevant to the current query type.
*/
if (instr->ntuples == 0)
continue;
ExplainOpenGroup("Trigger", NULL, true, es);
relname = RelationGetRelationName(rInfo->ri_RelationDesc);
if (OidIsValid(trig->tgconstraint))
conname = get_constraint_name(trig->tgconstraint);
/*
* In text format, we avoid printing both the trigger name and the
2010-02-26 03:01:40 +01:00
* constraint name unless VERBOSE is specified. In non-text formats
* we just print everything.
*/
if (es->format == EXPLAIN_FORMAT_TEXT)
{
if (es->verbose || conname == NULL)
appendStringInfo(es->str, "Trigger %s", trig->tgname);
else
appendStringInfoString(es->str, "Trigger");
if (conname)
appendStringInfo(es->str, " for constraint %s", conname);
if (show_relname)
appendStringInfo(es->str, " on %s", relname);
if (es->timing)
appendStringInfo(es->str, ": time=%.3f calls=%.0f\n",
1000.0 * instr->total, instr->ntuples);
else
appendStringInfo(es->str, ": calls=%.0f\n", instr->ntuples);
}
else
{
ExplainPropertyText("Trigger Name", trig->tgname, es);
if (conname)
ExplainPropertyText("Constraint Name", conname, es);
ExplainPropertyText("Relation", relname, es);
if (es->timing)
ExplainPropertyFloat("Time", 1000.0 * instr->total, 3, es);
ExplainPropertyFloat("Calls", instr->ntuples, 0, es);
}
if (conname)
pfree(conname);
ExplainCloseGroup("Trigger", NULL, true, es);
}
}
/* Compute elapsed time in seconds since given timestamp */
static double
elapsed_time(instr_time *starttime)
{
2005-10-15 04:49:52 +02:00
instr_time endtime;
INSTR_TIME_SET_CURRENT(endtime);
INSTR_TIME_SUBTRACT(endtime, *starttime);
return INSTR_TIME_GET_DOUBLE(endtime);
}
Improve ruleutils.c's heuristics for dealing with rangetable aliases. The previous scheme had bugs in some corner cases involving tables that had been renamed since a view was made. This could result in dumped views that failed to reload or reloaded incorrectly, as seen in bug #7553 from Lloyd Albin, as well as in some pgsql-hackers discussion back in January. Also, its behavior for printing EXPLAIN plans was sometimes confusing because of willingness to use the same alias for multiple RTEs (it was Ashutosh Bapat's complaint about that aspect that started the January thread). To fix, ensure that each RTE in the query has a unique unqualified alias, by modifying the alias if necessary (we add "_" and digits as needed to create a non-conflicting name). Then we can just print its variables with that alias, avoiding the confusing and bug-prone scheme of sometimes schema-qualifying variable names. In EXPLAIN, it proves to be expedient to take the further step of only assigning such aliases to RTEs that are actually referenced in the query, since the planner has a habit of generating extra RTEs with the same alias in situations such as inheritance-tree expansion. Although this fixes a bug of very long standing, I'm hesitant to back-patch such a noticeable behavioral change. My experiments while creating a regression test convinced me that actually incorrect output (as opposed to confusing output) occurs only in very narrow cases, which is backed up by the lack of previous complaints from the field. So we may be better off living with it in released branches; and in any case it'd be smart to let this ripen awhile in HEAD before we consider back-patching it.
2012-09-22 01:03:10 +02:00
/*
* ExplainPreScanNode -
* Prescan the planstate tree to identify which RTEs are referenced
*
* Adds the relid of each referenced RTE to *rels_used. The result controls
* which RTEs are assigned aliases by select_rtable_names_for_explain.
* This ensures that we don't confusingly assign un-suffixed aliases to RTEs
* that never appear in the EXPLAIN output (such as inheritance parents).
Improve ruleutils.c's heuristics for dealing with rangetable aliases. The previous scheme had bugs in some corner cases involving tables that had been renamed since a view was made. This could result in dumped views that failed to reload or reloaded incorrectly, as seen in bug #7553 from Lloyd Albin, as well as in some pgsql-hackers discussion back in January. Also, its behavior for printing EXPLAIN plans was sometimes confusing because of willingness to use the same alias for multiple RTEs (it was Ashutosh Bapat's complaint about that aspect that started the January thread). To fix, ensure that each RTE in the query has a unique unqualified alias, by modifying the alias if necessary (we add "_" and digits as needed to create a non-conflicting name). Then we can just print its variables with that alias, avoiding the confusing and bug-prone scheme of sometimes schema-qualifying variable names. In EXPLAIN, it proves to be expedient to take the further step of only assigning such aliases to RTEs that are actually referenced in the query, since the planner has a habit of generating extra RTEs with the same alias in situations such as inheritance-tree expansion. Although this fixes a bug of very long standing, I'm hesitant to back-patch such a noticeable behavioral change. My experiments while creating a regression test convinced me that actually incorrect output (as opposed to confusing output) occurs only in very narrow cases, which is backed up by the lack of previous complaints from the field. So we may be better off living with it in released branches; and in any case it'd be smart to let this ripen awhile in HEAD before we consider back-patching it.
2012-09-22 01:03:10 +02:00
*/
static bool
Improve ruleutils.c's heuristics for dealing with rangetable aliases. The previous scheme had bugs in some corner cases involving tables that had been renamed since a view was made. This could result in dumped views that failed to reload or reloaded incorrectly, as seen in bug #7553 from Lloyd Albin, as well as in some pgsql-hackers discussion back in January. Also, its behavior for printing EXPLAIN plans was sometimes confusing because of willingness to use the same alias for multiple RTEs (it was Ashutosh Bapat's complaint about that aspect that started the January thread). To fix, ensure that each RTE in the query has a unique unqualified alias, by modifying the alias if necessary (we add "_" and digits as needed to create a non-conflicting name). Then we can just print its variables with that alias, avoiding the confusing and bug-prone scheme of sometimes schema-qualifying variable names. In EXPLAIN, it proves to be expedient to take the further step of only assigning such aliases to RTEs that are actually referenced in the query, since the planner has a habit of generating extra RTEs with the same alias in situations such as inheritance-tree expansion. Although this fixes a bug of very long standing, I'm hesitant to back-patch such a noticeable behavioral change. My experiments while creating a regression test convinced me that actually incorrect output (as opposed to confusing output) occurs only in very narrow cases, which is backed up by the lack of previous complaints from the field. So we may be better off living with it in released branches; and in any case it'd be smart to let this ripen awhile in HEAD before we consider back-patching it.
2012-09-22 01:03:10 +02:00
ExplainPreScanNode(PlanState *planstate, Bitmapset **rels_used)
{
Plan *plan = planstate->plan;
switch (nodeTag(plan))
{
case T_SeqScan:
Redesign tablesample method API, and do extensive code review. The original implementation of TABLESAMPLE modeled the tablesample method API on index access methods, which wasn't a good choice because, without specialized DDL commands, there's no way to build an extension that can implement a TSM. (Raw inserts into system catalogs are not an acceptable thing to do, because we can't undo them during DROP EXTENSION, nor will pg_upgrade behave sanely.) Instead adopt an API more like procedural language handlers or foreign data wrappers, wherein the only SQL-level support object needed is a single handler function identified by having a special return type. This lets us get rid of the supporting catalog altogether, so that no custom DDL support is needed for the feature. Adjust the API so that it can support non-constant tablesample arguments (the original coding assumed we could evaluate the argument expressions at ExecInitSampleScan time, which is undesirable even if it weren't outright unsafe), and discourage sampling methods from looking at invisible tuples. Make sure that the BERNOULLI and SYSTEM methods are genuinely repeatable within and across queries, as required by the SQL standard, and deal more honestly with methods that can't support that requirement. Make a full code-review pass over the tablesample additions, and fix assorted bugs, omissions, infelicities, and cosmetic issues (such as failure to put the added code stanzas in a consistent ordering). Improve EXPLAIN's output of tablesample plans, too. Back-patch to 9.5 so that we don't have to support the original API in production.
2015-07-25 20:39:00 +02:00
case T_SampleScan:
Improve ruleutils.c's heuristics for dealing with rangetable aliases. The previous scheme had bugs in some corner cases involving tables that had been renamed since a view was made. This could result in dumped views that failed to reload or reloaded incorrectly, as seen in bug #7553 from Lloyd Albin, as well as in some pgsql-hackers discussion back in January. Also, its behavior for printing EXPLAIN plans was sometimes confusing because of willingness to use the same alias for multiple RTEs (it was Ashutosh Bapat's complaint about that aspect that started the January thread). To fix, ensure that each RTE in the query has a unique unqualified alias, by modifying the alias if necessary (we add "_" and digits as needed to create a non-conflicting name). Then we can just print its variables with that alias, avoiding the confusing and bug-prone scheme of sometimes schema-qualifying variable names. In EXPLAIN, it proves to be expedient to take the further step of only assigning such aliases to RTEs that are actually referenced in the query, since the planner has a habit of generating extra RTEs with the same alias in situations such as inheritance-tree expansion. Although this fixes a bug of very long standing, I'm hesitant to back-patch such a noticeable behavioral change. My experiments while creating a regression test convinced me that actually incorrect output (as opposed to confusing output) occurs only in very narrow cases, which is backed up by the lack of previous complaints from the field. So we may be better off living with it in released branches; and in any case it'd be smart to let this ripen awhile in HEAD before we consider back-patching it.
2012-09-22 01:03:10 +02:00
case T_IndexScan:
case T_IndexOnlyScan:
case T_BitmapHeapScan:
case T_TidScan:
case T_SubqueryScan:
case T_FunctionScan:
case T_TableFuncScan:
Improve ruleutils.c's heuristics for dealing with rangetable aliases. The previous scheme had bugs in some corner cases involving tables that had been renamed since a view was made. This could result in dumped views that failed to reload or reloaded incorrectly, as seen in bug #7553 from Lloyd Albin, as well as in some pgsql-hackers discussion back in January. Also, its behavior for printing EXPLAIN plans was sometimes confusing because of willingness to use the same alias for multiple RTEs (it was Ashutosh Bapat's complaint about that aspect that started the January thread). To fix, ensure that each RTE in the query has a unique unqualified alias, by modifying the alias if necessary (we add "_" and digits as needed to create a non-conflicting name). Then we can just print its variables with that alias, avoiding the confusing and bug-prone scheme of sometimes schema-qualifying variable names. In EXPLAIN, it proves to be expedient to take the further step of only assigning such aliases to RTEs that are actually referenced in the query, since the planner has a habit of generating extra RTEs with the same alias in situations such as inheritance-tree expansion. Although this fixes a bug of very long standing, I'm hesitant to back-patch such a noticeable behavioral change. My experiments while creating a regression test convinced me that actually incorrect output (as opposed to confusing output) occurs only in very narrow cases, which is backed up by the lack of previous complaints from the field. So we may be better off living with it in released branches; and in any case it'd be smart to let this ripen awhile in HEAD before we consider back-patching it.
2012-09-22 01:03:10 +02:00
case T_ValuesScan:
case T_CteScan:
case T_NamedTuplestoreScan:
Improve ruleutils.c's heuristics for dealing with rangetable aliases. The previous scheme had bugs in some corner cases involving tables that had been renamed since a view was made. This could result in dumped views that failed to reload or reloaded incorrectly, as seen in bug #7553 from Lloyd Albin, as well as in some pgsql-hackers discussion back in January. Also, its behavior for printing EXPLAIN plans was sometimes confusing because of willingness to use the same alias for multiple RTEs (it was Ashutosh Bapat's complaint about that aspect that started the January thread). To fix, ensure that each RTE in the query has a unique unqualified alias, by modifying the alias if necessary (we add "_" and digits as needed to create a non-conflicting name). Then we can just print its variables with that alias, avoiding the confusing and bug-prone scheme of sometimes schema-qualifying variable names. In EXPLAIN, it proves to be expedient to take the further step of only assigning such aliases to RTEs that are actually referenced in the query, since the planner has a habit of generating extra RTEs with the same alias in situations such as inheritance-tree expansion. Although this fixes a bug of very long standing, I'm hesitant to back-patch such a noticeable behavioral change. My experiments while creating a regression test convinced me that actually incorrect output (as opposed to confusing output) occurs only in very narrow cases, which is backed up by the lack of previous complaints from the field. So we may be better off living with it in released branches; and in any case it'd be smart to let this ripen awhile in HEAD before we consider back-patching it.
2012-09-22 01:03:10 +02:00
case T_WorkTableScan:
*rels_used = bms_add_member(*rels_used,
((Scan *) plan)->scanrelid);
break;
case T_ForeignScan:
*rels_used = bms_add_members(*rels_used,
Code review for foreign/custom join pushdown patch. Commit e7cb7ee14555cc9c5773e2c102efd6371f6f2005 included some design decisions that seem pretty questionable to me, and there was quite a lot of stuff not to like about the documentation and comments. Clean up as follows: * Consider foreign joins only between foreign tables on the same server, rather than between any two foreign tables with the same underlying FDW handler function. In most if not all cases, the FDW would simply have had to apply the same-server restriction itself (far more expensively, both for lack of caching and because it would be repeated for each combination of input sub-joins), or else risk nasty bugs. Anyone who's really intent on doing something outside this restriction can always use the set_join_pathlist_hook. * Rename fdw_ps_tlist/custom_ps_tlist to fdw_scan_tlist/custom_scan_tlist to better reflect what they're for, and allow these custom scan tlists to be used even for base relations. * Change make_foreignscan() API to include passing the fdw_scan_tlist value, since the FDW is required to set that. Backwards compatibility doesn't seem like an adequate reason to expect FDWs to set it in some ad-hoc extra step, and anyway existing FDWs can just pass NIL. * Change the API of path-generating subroutines of add_paths_to_joinrel, and in particular that of GetForeignJoinPaths and set_join_pathlist_hook, so that various less-used parameters are passed in a struct rather than as separate parameter-list entries. The objective here is to reduce the probability that future additions to those parameter lists will result in source-level API breaks for users of these hooks. It's possible that this is even a small win for the core code, since most CPU architectures can't pass more than half a dozen parameters efficiently anyway. I kept root, joinrel, outerrel, innerrel, and jointype as separate parameters to reduce code churn in joinpath.c --- in particular, putting jointype into the struct would have been problematic because of the subroutines' habit of changing their local copies of that variable. * Avoid ad-hocery in ExecAssignScanProjectionInfo. It was probably all right for it to know about IndexOnlyScan, but if the list is to grow we should refactor the knowledge out to the callers. * Restore nodeForeignscan.c's previous use of the relcache to avoid extra GetFdwRoutine lookups for base-relation scans. * Lots of cleanup of documentation and missed comments. Re-order some code additions into more logical places.
2015-05-10 20:36:30 +02:00
((ForeignScan *) plan)->fs_relids);
break;
case T_CustomScan:
*rels_used = bms_add_members(*rels_used,
((CustomScan *) plan)->custom_relids);
break;
Improve ruleutils.c's heuristics for dealing with rangetable aliases. The previous scheme had bugs in some corner cases involving tables that had been renamed since a view was made. This could result in dumped views that failed to reload or reloaded incorrectly, as seen in bug #7553 from Lloyd Albin, as well as in some pgsql-hackers discussion back in January. Also, its behavior for printing EXPLAIN plans was sometimes confusing because of willingness to use the same alias for multiple RTEs (it was Ashutosh Bapat's complaint about that aspect that started the January thread). To fix, ensure that each RTE in the query has a unique unqualified alias, by modifying the alias if necessary (we add "_" and digits as needed to create a non-conflicting name). Then we can just print its variables with that alias, avoiding the confusing and bug-prone scheme of sometimes schema-qualifying variable names. In EXPLAIN, it proves to be expedient to take the further step of only assigning such aliases to RTEs that are actually referenced in the query, since the planner has a habit of generating extra RTEs with the same alias in situations such as inheritance-tree expansion. Although this fixes a bug of very long standing, I'm hesitant to back-patch such a noticeable behavioral change. My experiments while creating a regression test convinced me that actually incorrect output (as opposed to confusing output) occurs only in very narrow cases, which is backed up by the lack of previous complaints from the field. So we may be better off living with it in released branches; and in any case it'd be smart to let this ripen awhile in HEAD before we consider back-patching it.
2012-09-22 01:03:10 +02:00
case T_ModifyTable:
*rels_used = bms_add_member(*rels_used,
((ModifyTable *) plan)->nominalRelation);
Add support for INSERT ... ON CONFLICT DO NOTHING/UPDATE. The newly added ON CONFLICT clause allows to specify an alternative to raising a unique or exclusion constraint violation error when inserting. ON CONFLICT refers to constraints that can either be specified using a inference clause (by specifying the columns of a unique constraint) or by naming a unique or exclusion constraint. DO NOTHING avoids the constraint violation, without touching the pre-existing row. DO UPDATE SET ... [WHERE ...] updates the pre-existing tuple, and has access to both the tuple proposed for insertion and the existing tuple; the optional WHERE clause can be used to prevent an update from being executed. The UPDATE SET and WHERE clauses have access to the tuple proposed for insertion using the "magic" EXCLUDED alias, and to the pre-existing tuple using the table name or its alias. This feature is often referred to as upsert. This is implemented using a new infrastructure called "speculative insertion". It is an optimistic variant of regular insertion that first does a pre-check for existing tuples and then attempts an insert. If a violating tuple was inserted concurrently, the speculatively inserted tuple is deleted and a new attempt is made. If the pre-check finds a matching tuple the alternative DO NOTHING or DO UPDATE action is taken. If the insertion succeeds without detecting a conflict, the tuple is deemed inserted. To handle the possible ambiguity between the excluded alias and a table named excluded, and for convenience with long relation names, INSERT INTO now can alias its target table. Bumps catversion as stored rules change. Author: Peter Geoghegan, with significant contributions from Heikki Linnakangas and Andres Freund. Testing infrastructure by Jeff Janes. Reviewed-By: Heikki Linnakangas, Andres Freund, Robert Haas, Simon Riggs, Dean Rasheed, Stephen Frost and many others.
2015-05-08 05:31:36 +02:00
if (((ModifyTable *) plan)->exclRelRTI)
*rels_used = bms_add_member(*rels_used,
((ModifyTable *) plan)->exclRelRTI);
Improve ruleutils.c's heuristics for dealing with rangetable aliases. The previous scheme had bugs in some corner cases involving tables that had been renamed since a view was made. This could result in dumped views that failed to reload or reloaded incorrectly, as seen in bug #7553 from Lloyd Albin, as well as in some pgsql-hackers discussion back in January. Also, its behavior for printing EXPLAIN plans was sometimes confusing because of willingness to use the same alias for multiple RTEs (it was Ashutosh Bapat's complaint about that aspect that started the January thread). To fix, ensure that each RTE in the query has a unique unqualified alias, by modifying the alias if necessary (we add "_" and digits as needed to create a non-conflicting name). Then we can just print its variables with that alias, avoiding the confusing and bug-prone scheme of sometimes schema-qualifying variable names. In EXPLAIN, it proves to be expedient to take the further step of only assigning such aliases to RTEs that are actually referenced in the query, since the planner has a habit of generating extra RTEs with the same alias in situations such as inheritance-tree expansion. Although this fixes a bug of very long standing, I'm hesitant to back-patch such a noticeable behavioral change. My experiments while creating a regression test convinced me that actually incorrect output (as opposed to confusing output) occurs only in very narrow cases, which is backed up by the lack of previous complaints from the field. So we may be better off living with it in released branches; and in any case it'd be smart to let this ripen awhile in HEAD before we consider back-patching it.
2012-09-22 01:03:10 +02:00
break;
default:
break;
}
return planstate_tree_walker(planstate, ExplainPreScanNode, rels_used);
Improve ruleutils.c's heuristics for dealing with rangetable aliases. The previous scheme had bugs in some corner cases involving tables that had been renamed since a view was made. This could result in dumped views that failed to reload or reloaded incorrectly, as seen in bug #7553 from Lloyd Albin, as well as in some pgsql-hackers discussion back in January. Also, its behavior for printing EXPLAIN plans was sometimes confusing because of willingness to use the same alias for multiple RTEs (it was Ashutosh Bapat's complaint about that aspect that started the January thread). To fix, ensure that each RTE in the query has a unique unqualified alias, by modifying the alias if necessary (we add "_" and digits as needed to create a non-conflicting name). Then we can just print its variables with that alias, avoiding the confusing and bug-prone scheme of sometimes schema-qualifying variable names. In EXPLAIN, it proves to be expedient to take the further step of only assigning such aliases to RTEs that are actually referenced in the query, since the planner has a habit of generating extra RTEs with the same alias in situations such as inheritance-tree expansion. Although this fixes a bug of very long standing, I'm hesitant to back-patch such a noticeable behavioral change. My experiments while creating a regression test convinced me that actually incorrect output (as opposed to confusing output) occurs only in very narrow cases, which is backed up by the lack of previous complaints from the field. So we may be better off living with it in released branches; and in any case it'd be smart to let this ripen awhile in HEAD before we consider back-patching it.
2012-09-22 01:03:10 +02:00
}
/*
* ExplainNode -
* Appends a description of a plan tree to es->str
*
* planstate points to the executor state node for the current plan node.
* We need to work from a PlanState node, not just a Plan node, in order to
* get at the instrumentation data (if any) as well as the list of subplans.
*
* ancestors is a list of parent PlanState nodes, most-closely-nested first.
* These are needed in order to interpret PARAM_EXEC Params.
*
* relationship describes the relationship of this plan node to its parent
* (eg, "Outer", "Inner"); it can be null at top level. plan_name is an
* optional name to be attached to the node.
*
* In text format, es->indent is controlled in this function since we only
* want it to change at plan-node boundaries. In non-text formats, es->indent
* corresponds to the nesting depth of logical output groups, and therefore
* is controlled by ExplainOpenGroup/ExplainCloseGroup.
*/
static void
ExplainNode(PlanState *planstate, List *ancestors,
const char *relationship, const char *plan_name,
ExplainState *es)
{
Plan *plan = planstate->plan;
const char *pname; /* node type name for text output */
const char *sname; /* node type name for non-text output */
const char *strategy = NULL;
const char *partialmode = NULL;
const char *operation = NULL;
const char *custom_name = NULL;
int save_indent = es->indent;
bool haschildren;
switch (nodeTag(plan))
{
case T_Result:
pname = sname = "Result";
break;
Move targetlist SRF handling from expression evaluation to new executor node. Evaluation of set returning functions (SRFs_ in the targetlist (like SELECT generate_series(1,5)) so far was done in the expression evaluation (i.e. ExecEvalExpr()) and projection (i.e. ExecProject/ExecTargetList) code. This meant that most executor nodes performing projection, and most expression evaluation functions, had to deal with the possibility that an evaluated expression could return a set of return values. That's bad because it leads to repeated code in a lot of places. It also, and that's my (Andres's) motivation, made it a lot harder to implement a more efficient way of doing expression evaluation. To fix this, introduce a new executor node (ProjectSet) that can evaluate targetlists containing one or more SRFs. To avoid the complexity of the old way of handling nested expressions returning sets (e.g. having to pass up ExprDoneCond, and dealing with arguments to functions returning sets etc.), those SRFs can only be at the top level of the node's targetlist. The planner makes sure (via split_pathtarget_at_srfs()) that SRF evaluation is only necessary in ProjectSet nodes and that SRFs are only present at the top level of the node's targetlist. If there are nested SRFs the planner creates multiple stacked ProjectSet nodes. The ProjectSet nodes always get input from an underlying node. We also discussed and prototyped evaluating targetlist SRFs using ROWS FROM(), but that turned out to be more complicated than we'd hoped. While moving SRF evaluation to ProjectSet would allow to retain the old "least common multiple" behavior when multiple SRFs are present in one targetlist (i.e. continue returning rows until all SRFs are at the end of their input at the same time), we decided to instead only return rows till all SRFs are exhausted, returning NULL for already exhausted ones. We deemed the previous behavior to be too confusing, unexpected and actually not particularly useful. As a side effect, the previously prohibited case of multiple set returning arguments to a function, is now allowed. Not because it's particularly desirable, but because it ends up working and there seems to be no argument for adding code to prohibit it. Currently the behavior for COALESCE and CASE containing SRFs has changed, returning multiple rows from the expression, even when the SRF containing "arm" of the expression is not evaluated. That's because the SRFs are evaluated in a separate ProjectSet node. As that's quite confusing, we're likely to instead prohibit SRFs in those places. But that's still being discussed, and the code would reside in places not touched here, so that's a task for later. There's a lot of, now superfluous, code dealing with set return expressions around. But as the changes to get rid of those are verbose largely boring, it seems better for readability to keep the cleanup as a separate commit. Author: Tom Lane and Andres Freund Discussion: https://postgr.es/m/20160822214023.aaxz5l4igypowyri@alap3.anarazel.de
2017-01-18 21:46:50 +01:00
case T_ProjectSet:
pname = sname = "ProjectSet";
break;
case T_ModifyTable:
sname = "ModifyTable";
switch (((ModifyTable *) plan)->operation)
{
case CMD_INSERT:
pname = operation = "Insert";
break;
case CMD_UPDATE:
pname = operation = "Update";
break;
case CMD_DELETE:
pname = operation = "Delete";
break;
default:
pname = "???";
break;
}
break;
case T_Append:
pname = sname = "Append";
break;
case T_MergeAppend:
pname = sname = "Merge Append";
break;
case T_RecursiveUnion:
pname = sname = "Recursive Union";
break;
case T_BitmapAnd:
pname = sname = "BitmapAnd";
break;
case T_BitmapOr:
pname = sname = "BitmapOr";
break;
case T_NestLoop:
pname = sname = "Nested Loop";
break;
case T_MergeJoin:
2010-02-26 03:01:40 +01:00
pname = "Merge"; /* "Join" gets added by jointype switch */
sname = "Merge Join";
break;
case T_HashJoin:
2010-02-26 03:01:40 +01:00
pname = "Hash"; /* "Join" gets added by jointype switch */
sname = "Hash Join";
break;
case T_SeqScan:
pname = sname = "Seq Scan";
break;
Redesign tablesample method API, and do extensive code review. The original implementation of TABLESAMPLE modeled the tablesample method API on index access methods, which wasn't a good choice because, without specialized DDL commands, there's no way to build an extension that can implement a TSM. (Raw inserts into system catalogs are not an acceptable thing to do, because we can't undo them during DROP EXTENSION, nor will pg_upgrade behave sanely.) Instead adopt an API more like procedural language handlers or foreign data wrappers, wherein the only SQL-level support object needed is a single handler function identified by having a special return type. This lets us get rid of the supporting catalog altogether, so that no custom DDL support is needed for the feature. Adjust the API so that it can support non-constant tablesample arguments (the original coding assumed we could evaluate the argument expressions at ExecInitSampleScan time, which is undesirable even if it weren't outright unsafe), and discourage sampling methods from looking at invisible tuples. Make sure that the BERNOULLI and SYSTEM methods are genuinely repeatable within and across queries, as required by the SQL standard, and deal more honestly with methods that can't support that requirement. Make a full code-review pass over the tablesample additions, and fix assorted bugs, omissions, infelicities, and cosmetic issues (such as failure to put the added code stanzas in a consistent ordering). Improve EXPLAIN's output of tablesample plans, too. Back-patch to 9.5 so that we don't have to support the original API in production.
2015-07-25 20:39:00 +02:00
case T_SampleScan:
pname = sname = "Sample Scan";
break;
case T_Gather:
pname = sname = "Gather";
break;
case T_GatherMerge:
pname = sname = "Gather Merge";
break;
case T_IndexScan:
pname = sname = "Index Scan";
break;
case T_IndexOnlyScan:
pname = sname = "Index Only Scan";
break;
case T_BitmapIndexScan:
pname = sname = "Bitmap Index Scan";
break;
case T_BitmapHeapScan:
pname = sname = "Bitmap Heap Scan";
break;
case T_TidScan:
pname = sname = "Tid Scan";
break;
case T_SubqueryScan:
pname = sname = "Subquery Scan";
break;
case T_FunctionScan:
pname = sname = "Function Scan";
break;
case T_TableFuncScan:
pname = sname = "Table Function Scan";
break;
case T_ValuesScan:
pname = sname = "Values Scan";
break;
case T_CteScan:
pname = sname = "CTE Scan";
break;
case T_NamedTuplestoreScan:
pname = sname = "Named Tuplestore Scan";
break;
case T_WorkTableScan:
pname = sname = "WorkTable Scan";
break;
case T_ForeignScan:
sname = "Foreign Scan";
switch (((ForeignScan *) plan)->operation)
{
case CMD_SELECT:
pname = "Foreign Scan";
operation = "Select";
break;
case CMD_INSERT:
pname = "Foreign Insert";
operation = "Insert";
break;
case CMD_UPDATE:
pname = "Foreign Update";
operation = "Update";
break;
case CMD_DELETE:
pname = "Foreign Delete";
operation = "Delete";
break;
default:
pname = "???";
break;
}
break;
case T_CustomScan:
sname = "Custom Scan";
custom_name = ((CustomScan *) plan)->methods->CustomName;
if (custom_name)
pname = psprintf("Custom Scan (%s)", custom_name);
else
pname = sname;
break;
case T_Material:
pname = sname = "Materialize";
break;
case T_Sort:
pname = sname = "Sort";
break;
case T_Group:
pname = sname = "Group";
break;
case T_Agg:
{
Agg *agg = (Agg *) plan;
sname = "Aggregate";
switch (agg->aggstrategy)
{
case AGG_PLAIN:
pname = "Aggregate";
strategy = "Plain";
break;
case AGG_SORTED:
pname = "GroupAggregate";
strategy = "Sorted";
break;
case AGG_HASHED:
pname = "HashAggregate";
strategy = "Hashed";
break;
case AGG_MIXED:
pname = "MixedAggregate";
strategy = "Mixed";
break;
default:
pname = "Aggregate ???";
strategy = "???";
break;
}
if (DO_AGGSPLIT_SKIPFINAL(agg->aggsplit))
{
partialmode = "Partial";
pname = psprintf("%s %s", partialmode, pname);
}
else if (DO_AGGSPLIT_COMBINE(agg->aggsplit))
{
partialmode = "Finalize";
pname = psprintf("%s %s", partialmode, pname);
}
else
partialmode = "Simple";
}
break;
case T_WindowAgg:
pname = sname = "WindowAgg";
break;
case T_Unique:
pname = sname = "Unique";
break;
case T_SetOp:
sname = "SetOp";
switch (((SetOp *) plan)->strategy)
{
case SETOP_SORTED:
pname = "SetOp";
strategy = "Sorted";
break;
case SETOP_HASHED:
pname = "HashSetOp";
strategy = "Hashed";
break;
default:
pname = "SetOp ???";
strategy = "???";
break;
}
break;
case T_LockRows:
pname = sname = "LockRows";
break;
case T_Limit:
pname = sname = "Limit";
break;
case T_Hash:
pname = sname = "Hash";
break;
default:
pname = sname = "???";
break;
}
ExplainOpenGroup("Plan",
relationship ? NULL : "Plan",
true, es);
if (es->format == EXPLAIN_FORMAT_TEXT)
{
if (plan_name)
{
appendStringInfoSpaces(es->str, es->indent * 2);
appendStringInfo(es->str, "%s\n", plan_name);
es->indent++;
}
if (es->indent)
{
appendStringInfoSpaces(es->str, es->indent * 2);
appendStringInfoString(es->str, "-> ");
es->indent += 2;
}
if (plan->parallel_aware)
appendStringInfoString(es->str, "Parallel ");
appendStringInfoString(es->str, pname);
es->indent++;
}
else
{
ExplainPropertyText("Node Type", sname, es);
if (strategy)
ExplainPropertyText("Strategy", strategy, es);
if (partialmode)
ExplainPropertyText("Partial Mode", partialmode, es);
if (operation)
ExplainPropertyText("Operation", operation, es);
if (relationship)
ExplainPropertyText("Parent Relationship", relationship, es);
if (plan_name)
ExplainPropertyText("Subplan Name", plan_name, es);
if (custom_name)
ExplainPropertyText("Custom Plan Provider", custom_name, es);
ExplainPropertyBool("Parallel Aware", plan->parallel_aware, es);
}
switch (nodeTag(plan))
{
case T_SeqScan:
Redesign tablesample method API, and do extensive code review. The original implementation of TABLESAMPLE modeled the tablesample method API on index access methods, which wasn't a good choice because, without specialized DDL commands, there's no way to build an extension that can implement a TSM. (Raw inserts into system catalogs are not an acceptable thing to do, because we can't undo them during DROP EXTENSION, nor will pg_upgrade behave sanely.) Instead adopt an API more like procedural language handlers or foreign data wrappers, wherein the only SQL-level support object needed is a single handler function identified by having a special return type. This lets us get rid of the supporting catalog altogether, so that no custom DDL support is needed for the feature. Adjust the API so that it can support non-constant tablesample arguments (the original coding assumed we could evaluate the argument expressions at ExecInitSampleScan time, which is undesirable even if it weren't outright unsafe), and discourage sampling methods from looking at invisible tuples. Make sure that the BERNOULLI and SYSTEM methods are genuinely repeatable within and across queries, as required by the SQL standard, and deal more honestly with methods that can't support that requirement. Make a full code-review pass over the tablesample additions, and fix assorted bugs, omissions, infelicities, and cosmetic issues (such as failure to put the added code stanzas in a consistent ordering). Improve EXPLAIN's output of tablesample plans, too. Back-patch to 9.5 so that we don't have to support the original API in production.
2015-07-25 20:39:00 +02:00
case T_SampleScan:
case T_BitmapHeapScan:
case T_TidScan:
case T_SubqueryScan:
case T_FunctionScan:
case T_TableFuncScan:
case T_ValuesScan:
case T_CteScan:
case T_WorkTableScan:
ExplainScanTarget((Scan *) plan, es);
break;
case T_ForeignScan:
case T_CustomScan:
if (((Scan *) plan)->scanrelid > 0)
ExplainScanTarget((Scan *) plan, es);
break;
case T_IndexScan:
{
IndexScan *indexscan = (IndexScan *) plan;
ExplainIndexScanDetails(indexscan->indexid,
indexscan->indexorderdir,
es);
ExplainScanTarget((Scan *) indexscan, es);
}
break;
case T_IndexOnlyScan:
{
IndexOnlyScan *indexonlyscan = (IndexOnlyScan *) plan;
ExplainIndexScanDetails(indexonlyscan->indexid,
indexonlyscan->indexorderdir,
es);
ExplainScanTarget((Scan *) indexonlyscan, es);
}
break;
case T_BitmapIndexScan:
{
BitmapIndexScan *bitmapindexscan = (BitmapIndexScan *) plan;
const char *indexname =
2010-02-26 03:01:40 +01:00
explain_get_index_name(bitmapindexscan->indexid);
if (es->format == EXPLAIN_FORMAT_TEXT)
appendStringInfo(es->str, " on %s", indexname);
else
ExplainPropertyText("Index Name", indexname, es);
}
break;
case T_ModifyTable:
ExplainModifyTarget((ModifyTable *) plan, es);
break;
case T_NestLoop:
case T_MergeJoin:
case T_HashJoin:
{
const char *jointype;
switch (((Join *) plan)->jointype)
{
case JOIN_INNER:
jointype = "Inner";
break;
case JOIN_LEFT:
jointype = "Left";
break;
case JOIN_FULL:
jointype = "Full";
break;
case JOIN_RIGHT:
jointype = "Right";
break;
case JOIN_SEMI:
jointype = "Semi";
break;
case JOIN_ANTI:
jointype = "Anti";
break;
default:
jointype = "???";
break;
}
if (es->format == EXPLAIN_FORMAT_TEXT)
{
/*
* For historical reasons, the join type is interpolated
* into the node type name...
*/
if (((Join *) plan)->jointype != JOIN_INNER)
appendStringInfo(es->str, " %s Join", jointype);
else if (!IsA(plan, NestLoop))
appendStringInfoString(es->str, " Join");
}
else
ExplainPropertyText("Join Type", jointype, es);
}
break;
case T_SetOp:
{
const char *setopcmd;
switch (((SetOp *) plan)->cmd)
{
case SETOPCMD_INTERSECT:
setopcmd = "Intersect";
break;
case SETOPCMD_INTERSECT_ALL:
setopcmd = "Intersect All";
break;
case SETOPCMD_EXCEPT:
setopcmd = "Except";
break;
case SETOPCMD_EXCEPT_ALL:
setopcmd = "Except All";
break;
default:
setopcmd = "???";
break;
}
if (es->format == EXPLAIN_FORMAT_TEXT)
appendStringInfo(es->str, " %s", setopcmd);
else
ExplainPropertyText("Command", setopcmd, es);
}
break;
default:
break;
}
2005-10-15 04:49:52 +02:00
if (es->costs)
{
if (es->format == EXPLAIN_FORMAT_TEXT)
{
appendStringInfo(es->str, " (cost=%.2f..%.2f rows=%.0f width=%d)",
plan->startup_cost, plan->total_cost,
plan->plan_rows, plan->plan_width);
}
else
{
ExplainPropertyFloat("Startup Cost", plan->startup_cost, 2, es);
ExplainPropertyFloat("Total Cost", plan->total_cost, 2, es);
ExplainPropertyFloat("Plan Rows", plan->plan_rows, 0, es);
ExplainPropertyInteger("Plan Width", plan->plan_width, es);
}
}
/*
2005-10-15 04:49:52 +02:00
* We have to forcibly clean up the instrumentation state because we
* haven't done ExecutorEnd yet. This is pretty grotty ...
*
* Note: contrib/auto_explain could cause instrumentation to be set up
* even though we didn't ask for it here. Be careful not to print any
* instrumentation results the user didn't ask for. But we do the
* InstrEndLoop call anyway, if possible, to reduce the number of cases
* auto_explain has to contend with.
*/
if (planstate->instrument)
InstrEndLoop(planstate->instrument);
if (es->analyze &&
planstate->instrument && planstate->instrument->nloops > 0)
{
double nloops = planstate->instrument->nloops;
double startup_sec = 1000.0 * planstate->instrument->startup / nloops;
double total_sec = 1000.0 * planstate->instrument->total / nloops;
double rows = planstate->instrument->ntuples / nloops;
if (es->format == EXPLAIN_FORMAT_TEXT)
{
if (es->timing)
appendStringInfo(es->str,
" (actual time=%.3f..%.3f rows=%.0f loops=%.0f)",
startup_sec, total_sec, rows, nloops);
else
appendStringInfo(es->str,
" (actual rows=%.0f loops=%.0f)",
rows, nloops);
}
else
{
if (es->timing)
{
ExplainPropertyFloat("Actual Startup Time", startup_sec, 3, es);
ExplainPropertyFloat("Actual Total Time", total_sec, 3, es);
}
ExplainPropertyFloat("Actual Rows", rows, 0, es);
ExplainPropertyFloat("Actual Loops", nloops, 0, es);
}
}
else if (es->analyze)
{
if (es->format == EXPLAIN_FORMAT_TEXT)
appendStringInfoString(es->str, " (never executed)");
else
{
if (es->timing)
{
ExplainPropertyFloat("Actual Startup Time", 0.0, 3, es);
ExplainPropertyFloat("Actual Total Time", 0.0, 3, es);
}
ExplainPropertyFloat("Actual Rows", 0.0, 0, es);
ExplainPropertyFloat("Actual Loops", 0.0, 0, es);
}
}
/* in text format, first line ends here */
if (es->format == EXPLAIN_FORMAT_TEXT)
appendStringInfoChar(es->str, '\n');
/* target list */
if (es->verbose)
show_plan_tlist(planstate, ancestors, es);
/* unique join */
switch (nodeTag(plan))
{
case T_NestLoop:
case T_MergeJoin:
case T_HashJoin:
/* try not to be too chatty about this in text mode */
if (es->format != EXPLAIN_FORMAT_TEXT ||
(es->verbose && ((Join *) plan)->inner_unique))
ExplainPropertyBool("Inner Unique",
((Join *) plan)->inner_unique,
es);
break;
default:
break;
}
/* quals, sort keys, etc */
switch (nodeTag(plan))
{
case T_IndexScan:
show_scan_qual(((IndexScan *) plan)->indexqualorig,
"Index Cond", planstate, ancestors, es);
if (((IndexScan *) plan)->indexqualorig)
show_instrumentation_count("Rows Removed by Index Recheck", 2,
planstate, es);
show_scan_qual(((IndexScan *) plan)->indexorderbyorig,
"Order By", planstate, ancestors, es);
show_scan_qual(plan->qual, "Filter", planstate, ancestors, es);
if (plan->qual)
show_instrumentation_count("Rows Removed by Filter", 1,
planstate, es);
break;
case T_IndexOnlyScan:
show_scan_qual(((IndexOnlyScan *) plan)->indexqual,
"Index Cond", planstate, ancestors, es);
if (((IndexOnlyScan *) plan)->indexqual)
show_instrumentation_count("Rows Removed by Index Recheck", 2,
planstate, es);
show_scan_qual(((IndexOnlyScan *) plan)->indexorderby,
"Order By", planstate, ancestors, es);
show_scan_qual(plan->qual, "Filter", planstate, ancestors, es);
if (plan->qual)
show_instrumentation_count("Rows Removed by Filter", 1,
planstate, es);
if (es->analyze)
ExplainPropertyLong("Heap Fetches",
((IndexOnlyScanState *) planstate)->ioss_HeapFetches, es);
break;
case T_BitmapIndexScan:
show_scan_qual(((BitmapIndexScan *) plan)->indexqualorig,
"Index Cond", planstate, ancestors, es);
break;
case T_BitmapHeapScan:
show_scan_qual(((BitmapHeapScan *) plan)->bitmapqualorig,
"Recheck Cond", planstate, ancestors, es);
if (((BitmapHeapScan *) plan)->bitmapqualorig)
show_instrumentation_count("Rows Removed by Index Recheck", 2,
planstate, es);
show_scan_qual(plan->qual, "Filter", planstate, ancestors, es);
if (plan->qual)
show_instrumentation_count("Rows Removed by Filter", 1,
planstate, es);
if (es->analyze)
show_tidbitmap_info((BitmapHeapScanState *) planstate, es);
break;
Redesign tablesample method API, and do extensive code review. The original implementation of TABLESAMPLE modeled the tablesample method API on index access methods, which wasn't a good choice because, without specialized DDL commands, there's no way to build an extension that can implement a TSM. (Raw inserts into system catalogs are not an acceptable thing to do, because we can't undo them during DROP EXTENSION, nor will pg_upgrade behave sanely.) Instead adopt an API more like procedural language handlers or foreign data wrappers, wherein the only SQL-level support object needed is a single handler function identified by having a special return type. This lets us get rid of the supporting catalog altogether, so that no custom DDL support is needed for the feature. Adjust the API so that it can support non-constant tablesample arguments (the original coding assumed we could evaluate the argument expressions at ExecInitSampleScan time, which is undesirable even if it weren't outright unsafe), and discourage sampling methods from looking at invisible tuples. Make sure that the BERNOULLI and SYSTEM methods are genuinely repeatable within and across queries, as required by the SQL standard, and deal more honestly with methods that can't support that requirement. Make a full code-review pass over the tablesample additions, and fix assorted bugs, omissions, infelicities, and cosmetic issues (such as failure to put the added code stanzas in a consistent ordering). Improve EXPLAIN's output of tablesample plans, too. Back-patch to 9.5 so that we don't have to support the original API in production.
2015-07-25 20:39:00 +02:00
case T_SampleScan:
show_tablesample(((SampleScan *) plan)->tablesample,
planstate, ancestors, es);
/* FALL THRU to print additional fields the same as SeqScan */
case T_SeqScan:
case T_ValuesScan:
case T_CteScan:
case T_NamedTuplestoreScan:
case T_WorkTableScan:
case T_SubqueryScan:
show_scan_qual(plan->qual, "Filter", planstate, ancestors, es);
if (plan->qual)
show_instrumentation_count("Rows Removed by Filter", 1,
planstate, es);
break;
case T_Gather:
{
Gather *gather = (Gather *) plan;
show_scan_qual(plan->qual, "Filter", planstate, ancestors, es);
if (plan->qual)
show_instrumentation_count("Rows Removed by Filter", 1,
planstate, es);
ExplainPropertyInteger("Workers Planned",
gather->num_workers, es);
if (es->analyze)
{
int nworkers;
nworkers = ((GatherState *) planstate)->nworkers_launched;
ExplainPropertyInteger("Workers Launched",
nworkers, es);
}
if (gather->single_copy || es->format != EXPLAIN_FORMAT_TEXT)
ExplainPropertyBool("Single Copy", gather->single_copy, es);
}
break;
case T_GatherMerge:
{
GatherMerge *gm = (GatherMerge *) plan;
show_scan_qual(plan->qual, "Filter", planstate, ancestors, es);
if (plan->qual)
show_instrumentation_count("Rows Removed by Filter", 1,
planstate, es);
ExplainPropertyInteger("Workers Planned",
gm->num_workers, es);
if (es->analyze)
{
int nworkers;
nworkers = ((GatherMergeState *) planstate)->nworkers_launched;
ExplainPropertyInteger("Workers Launched",
nworkers, es);
}
}
break;
case T_FunctionScan:
if (es->verbose)
{
List *fexprs = NIL;
ListCell *lc;
foreach(lc, ((FunctionScan *) plan)->functions)
{
RangeTblFunction *rtfunc = (RangeTblFunction *) lfirst(lc);
fexprs = lappend(fexprs, rtfunc->funcexpr);
}
/* We rely on show_expression to insert commas as needed */
show_expression((Node *) fexprs,
"Function Call", planstate, ancestors,
es->verbose, es);
}
show_scan_qual(plan->qual, "Filter", planstate, ancestors, es);
if (plan->qual)
show_instrumentation_count("Rows Removed by Filter", 1,
planstate, es);
break;
case T_TableFuncScan:
if (es->verbose)
{
TableFunc *tablefunc = ((TableFuncScan *) plan)->tablefunc;
show_expression((Node *) tablefunc,
"Table Function Call", planstate, ancestors,
es->verbose, es);
}
show_scan_qual(plan->qual, "Filter", planstate, ancestors, es);
if (plan->qual)
show_instrumentation_count("Rows Removed by Filter", 1,
planstate, es);
break;
case T_TidScan:
{
/*
* The tidquals list has OR semantics, so be sure to show it
* as an OR condition.
*/
2006-10-04 02:30:14 +02:00
List *tidquals = ((TidScan *) plan)->tidquals;
if (list_length(tidquals) > 1)
tidquals = list_make1(make_orclause(tidquals));
show_scan_qual(tidquals, "TID Cond", planstate, ancestors, es);
show_scan_qual(plan->qual, "Filter", planstate, ancestors, es);
if (plan->qual)
show_instrumentation_count("Rows Removed by Filter", 1,
planstate, es);
}
break;
case T_ForeignScan:
show_scan_qual(plan->qual, "Filter", planstate, ancestors, es);
if (plan->qual)
show_instrumentation_count("Rows Removed by Filter", 1,
planstate, es);
show_foreignscan_info((ForeignScanState *) planstate, es);
break;
case T_CustomScan:
{
CustomScanState *css = (CustomScanState *) planstate;
show_scan_qual(plan->qual, "Filter", planstate, ancestors, es);
if (plan->qual)
show_instrumentation_count("Rows Removed by Filter", 1,
planstate, es);
if (css->methods->ExplainCustomScan)
css->methods->ExplainCustomScan(css, ancestors, es);
}
break;
case T_NestLoop:
show_upper_qual(((NestLoop *) plan)->join.joinqual,
"Join Filter", planstate, ancestors, es);
if (((NestLoop *) plan)->join.joinqual)
show_instrumentation_count("Rows Removed by Join Filter", 1,
planstate, es);
show_upper_qual(plan->qual, "Filter", planstate, ancestors, es);
if (plan->qual)
show_instrumentation_count("Rows Removed by Filter", 2,
planstate, es);
break;
case T_MergeJoin:
show_upper_qual(((MergeJoin *) plan)->mergeclauses,
"Merge Cond", planstate, ancestors, es);
show_upper_qual(((MergeJoin *) plan)->join.joinqual,
"Join Filter", planstate, ancestors, es);
if (((MergeJoin *) plan)->join.joinqual)
show_instrumentation_count("Rows Removed by Join Filter", 1,
planstate, es);
show_upper_qual(plan->qual, "Filter", planstate, ancestors, es);
if (plan->qual)
show_instrumentation_count("Rows Removed by Filter", 2,
planstate, es);
break;
case T_HashJoin:
show_upper_qual(((HashJoin *) plan)->hashclauses,
"Hash Cond", planstate, ancestors, es);
show_upper_qual(((HashJoin *) plan)->join.joinqual,
"Join Filter", planstate, ancestors, es);
if (((HashJoin *) plan)->join.joinqual)
show_instrumentation_count("Rows Removed by Join Filter", 1,
planstate, es);
show_upper_qual(plan->qual, "Filter", planstate, ancestors, es);
if (plan->qual)
show_instrumentation_count("Rows Removed by Filter", 2,
planstate, es);
break;
case T_Agg:
show_agg_keys(castNode(AggState, planstate), ancestors, es);
show_upper_qual(plan->qual, "Filter", planstate, ancestors, es);
if (plan->qual)
show_instrumentation_count("Rows Removed by Filter", 1,
planstate, es);
break;
case T_Group:
show_group_keys(castNode(GroupState, planstate), ancestors, es);
show_upper_qual(plan->qual, "Filter", planstate, ancestors, es);
if (plan->qual)
show_instrumentation_count("Rows Removed by Filter", 1,
planstate, es);
break;
case T_Sort:
show_sort_keys(castNode(SortState, planstate), ancestors, es);
show_sort_info(castNode(SortState, planstate), es);
break;
case T_MergeAppend:
show_merge_append_keys(castNode(MergeAppendState, planstate),
ancestors, es);
break;
case T_Result:
show_upper_qual((List *) ((Result *) plan)->resconstantqual,
"One-Time Filter", planstate, ancestors, es);
show_upper_qual(plan->qual, "Filter", planstate, ancestors, es);
if (plan->qual)
show_instrumentation_count("Rows Removed by Filter", 1,
planstate, es);
break;
case T_ModifyTable:
show_modifytable_info(castNode(ModifyTableState, planstate), ancestors,
Add support for INSERT ... ON CONFLICT DO NOTHING/UPDATE. The newly added ON CONFLICT clause allows to specify an alternative to raising a unique or exclusion constraint violation error when inserting. ON CONFLICT refers to constraints that can either be specified using a inference clause (by specifying the columns of a unique constraint) or by naming a unique or exclusion constraint. DO NOTHING avoids the constraint violation, without touching the pre-existing row. DO UPDATE SET ... [WHERE ...] updates the pre-existing tuple, and has access to both the tuple proposed for insertion and the existing tuple; the optional WHERE clause can be used to prevent an update from being executed. The UPDATE SET and WHERE clauses have access to the tuple proposed for insertion using the "magic" EXCLUDED alias, and to the pre-existing tuple using the table name or its alias. This feature is often referred to as upsert. This is implemented using a new infrastructure called "speculative insertion". It is an optimistic variant of regular insertion that first does a pre-check for existing tuples and then attempts an insert. If a violating tuple was inserted concurrently, the speculatively inserted tuple is deleted and a new attempt is made. If the pre-check finds a matching tuple the alternative DO NOTHING or DO UPDATE action is taken. If the insertion succeeds without detecting a conflict, the tuple is deemed inserted. To handle the possible ambiguity between the excluded alias and a table named excluded, and for convenience with long relation names, INSERT INTO now can alias its target table. Bumps catversion as stored rules change. Author: Peter Geoghegan, with significant contributions from Heikki Linnakangas and Andres Freund. Testing infrastructure by Jeff Janes. Reviewed-By: Heikki Linnakangas, Andres Freund, Robert Haas, Simon Riggs, Dean Rasheed, Stephen Frost and many others.
2015-05-08 05:31:36 +02:00
es);
break;
case T_Hash:
show_hash_info(castNode(HashState, planstate), es);
break;
default:
break;
}
/* Show buffer usage */
if (es->buffers && planstate->instrument)
show_buffer_usage(es, &planstate->instrument->bufusage);
/* Show worker detail */
if (es->analyze && es->verbose && planstate->worker_instrument)
{
WorkerInstrumentation *w = planstate->worker_instrument;
bool opened_group = false;
int n;
for (n = 0; n < w->num_workers; ++n)
{
Instrumentation *instrument = &w->instrument[n];
double nloops = instrument->nloops;
double startup_sec;
double total_sec;
double rows;
if (nloops <= 0)
continue;
startup_sec = 1000.0 * instrument->startup / nloops;
total_sec = 1000.0 * instrument->total / nloops;
rows = instrument->ntuples / nloops;
if (es->format == EXPLAIN_FORMAT_TEXT)
{
appendStringInfoSpaces(es->str, es->indent * 2);
appendStringInfo(es->str, "Worker %d: ", n);
if (es->timing)
appendStringInfo(es->str,
"actual time=%.3f..%.3f rows=%.0f loops=%.0f\n",
startup_sec, total_sec, rows, nloops);
else
appendStringInfo(es->str,
"actual rows=%.0f loops=%.0f\n",
rows, nloops);
es->indent++;
if (es->buffers)
show_buffer_usage(es, &instrument->bufusage);
es->indent--;
}
else
{
if (!opened_group)
{
ExplainOpenGroup("Workers", "Workers", false, es);
opened_group = true;
}
ExplainOpenGroup("Worker", NULL, true, es);
ExplainPropertyInteger("Worker Number", n, es);
if (es->timing)
{
ExplainPropertyFloat("Actual Startup Time", startup_sec, 3, es);
ExplainPropertyFloat("Actual Total Time", total_sec, 3, es);
}
ExplainPropertyFloat("Actual Rows", rows, 0, es);
ExplainPropertyFloat("Actual Loops", nloops, 0, es);
if (es->buffers)
show_buffer_usage(es, &instrument->bufusage);
ExplainCloseGroup("Worker", NULL, true, es);
}
}
if (opened_group)
ExplainCloseGroup("Workers", "Workers", false, es);
}
/* Get ready to display the child plans */
haschildren = planstate->initPlan ||
outerPlanState(planstate) ||
innerPlanState(planstate) ||
IsA(plan, ModifyTable) ||
IsA(plan, Append) ||
IsA(plan, MergeAppend) ||
IsA(plan, BitmapAnd) ||
IsA(plan, BitmapOr) ||
IsA(plan, SubqueryScan) ||
(IsA(planstate, CustomScanState) &&
((CustomScanState *) planstate)->custom_ps != NIL) ||
planstate->subPlan;
if (haschildren)
{
ExplainOpenGroup("Plans", "Plans", false, es);
/* Pass current PlanState as head of ancestors list for children */
ancestors = lcons(planstate, ancestors);
}
1998-02-13 04:21:30 +01:00
/* initPlan-s */
if (planstate->initPlan)
ExplainSubPlans(planstate->initPlan, ancestors, "InitPlan", es);
/* lefttree */
if (outerPlanState(planstate))
ExplainNode(outerPlanState(planstate), ancestors,
"Outer", NULL, es);
/* righttree */
if (innerPlanState(planstate))
ExplainNode(innerPlanState(planstate), ancestors,
"Inner", NULL, es);
/* special child plans */
switch (nodeTag(plan))
{
case T_ModifyTable:
ExplainMemberNodes(((ModifyTable *) plan)->plans,
((ModifyTableState *) planstate)->mt_plans,
ancestors, es);
break;
case T_Append:
ExplainMemberNodes(((Append *) plan)->appendplans,
((AppendState *) planstate)->appendplans,
ancestors, es);
break;
case T_MergeAppend:
ExplainMemberNodes(((MergeAppend *) plan)->mergeplans,
((MergeAppendState *) planstate)->mergeplans,
ancestors, es);
break;
case T_BitmapAnd:
ExplainMemberNodes(((BitmapAnd *) plan)->bitmapplans,
((BitmapAndState *) planstate)->bitmapplans,
ancestors, es);
break;
case T_BitmapOr:
ExplainMemberNodes(((BitmapOr *) plan)->bitmapplans,
((BitmapOrState *) planstate)->bitmapplans,
ancestors, es);
break;
case T_SubqueryScan:
ExplainNode(((SubqueryScanState *) planstate)->subplan, ancestors,
"Subquery", NULL, es);
break;
case T_CustomScan:
ExplainCustomChildren((CustomScanState *) planstate,
ancestors, es);
break;
default:
break;
}
/* subPlan-s */
if (planstate->subPlan)
ExplainSubPlans(planstate->subPlan, ancestors, "SubPlan", es);
/* end of child plans */
if (haschildren)
{
ancestors = list_delete_first(ancestors);
ExplainCloseGroup("Plans", "Plans", false, es);
}
/* in text format, undo whatever indentation we added */
if (es->format == EXPLAIN_FORMAT_TEXT)
es->indent = save_indent;
ExplainCloseGroup("Plan",
relationship ? NULL : "Plan",
true, es);
}
/*
* Show the targetlist of a plan node
*/
static void
show_plan_tlist(PlanState *planstate, List *ancestors, ExplainState *es)
{
Plan *plan = planstate->plan;
List *context;
List *result = NIL;
bool useprefix;
ListCell *lc;
/* No work if empty tlist (this occurs eg in bitmap indexscans) */
if (plan->targetlist == NIL)
return;
/* The tlist of an Append isn't real helpful, so suppress it */
if (IsA(plan, Append))
return;
/* Likewise for MergeAppend and RecursiveUnion */
if (IsA(plan, MergeAppend))
return;
if (IsA(plan, RecursiveUnion))
return;
/*
* Likewise for ForeignScan that executes a direct INSERT/UPDATE/DELETE
*
* Note: the tlist for a ForeignScan that executes a direct INSERT/UPDATE
* might contain subplan output expressions that are confusing in this
* context. The tlist for a ForeignScan that executes a direct UPDATE/
* DELETE always contains "junk" target columns to identify the exact row
* to update or delete, which would be confusing in this context. So, we
* suppress it in all the cases.
*/
if (IsA(plan, ForeignScan) &&
((ForeignScan *) plan)->operation != CMD_SELECT)
return;
/* Set up deparsing context */
context = set_deparse_context_planstate(es->deparse_cxt,
(Node *) planstate,
ancestors);
useprefix = list_length(es->rtable) > 1;
/* Deparse each result column (we now include resjunk ones) */
foreach(lc, plan->targetlist)
{
TargetEntry *tle = (TargetEntry *) lfirst(lc);
result = lappend(result,
2010-02-26 03:01:40 +01:00
deparse_expression((Node *) tle->expr, context,
useprefix, false));
}
/* Print results */
ExplainPropertyList("Output", result, es);
}
/*
* Show a generic expression
*/
static void
show_expression(Node *node, const char *qlabel,
PlanState *planstate, List *ancestors,
bool useprefix, ExplainState *es)
{
List *context;
char *exprstr;
/* Set up deparsing context */
context = set_deparse_context_planstate(es->deparse_cxt,
(Node *) planstate,
ancestors);
/* Deparse the expression */
exprstr = deparse_expression(node, context, useprefix, false);
/* And add to es->str */
ExplainPropertyText(qlabel, exprstr, es);
}
/*
* Show a qualifier expression (which is a List with implicit AND semantics)
*/
static void
show_qual(List *qual, const char *qlabel,
PlanState *planstate, List *ancestors,
bool useprefix, ExplainState *es)
{
Node *node;
/* No work if empty qual */
if (qual == NIL)
return;
/* Convert AND list to explicit AND */
node = (Node *) make_ands_explicit(qual);
/* And show it */
show_expression(node, qlabel, planstate, ancestors, useprefix, es);
}
/*
* Show a qualifier expression for a scan plan node
*/
static void
show_scan_qual(List *qual, const char *qlabel,
PlanState *planstate, List *ancestors,
ExplainState *es)
{
bool useprefix;
2011-04-10 17:42:00 +02:00
useprefix = (IsA(planstate->plan, SubqueryScan) ||es->verbose);
show_qual(qual, qlabel, planstate, ancestors, useprefix, es);
}
/*
* Show a qualifier expression for an upper-level plan node
*/
static void
show_upper_qual(List *qual, const char *qlabel,
PlanState *planstate, List *ancestors,
ExplainState *es)
{
bool useprefix;
useprefix = (list_length(es->rtable) > 1 || es->verbose);
show_qual(qual, qlabel, planstate, ancestors, useprefix, es);
}
/*
* Show the sort keys for a Sort node.
*/
static void
show_sort_keys(SortState *sortstate, List *ancestors, ExplainState *es)
{
Sort *plan = (Sort *) sortstate->ss.ps.plan;
show_sort_group_keys((PlanState *) sortstate, "Sort Key",
plan->numCols, plan->sortColIdx,
plan->sortOperators, plan->collations,
plan->nullsFirst,
ancestors, es);
}
/*
* Likewise, for a MergeAppend node.
*/
static void
show_merge_append_keys(MergeAppendState *mstate, List *ancestors,
ExplainState *es)
{
MergeAppend *plan = (MergeAppend *) mstate->ps.plan;
show_sort_group_keys((PlanState *) mstate, "Sort Key",
plan->numCols, plan->sortColIdx,
plan->sortOperators, plan->collations,
plan->nullsFirst,
ancestors, es);
}
/*
* Show the grouping keys for an Agg node.
*/
static void
show_agg_keys(AggState *astate, List *ancestors,
ExplainState *es)
{
Agg *plan = (Agg *) astate->ss.ps.plan;
Support GROUPING SETS, CUBE and ROLLUP. This SQL standard functionality allows to aggregate data by different GROUP BY clauses at once. Each grouping set returns rows with columns grouped by in other sets set to NULL. This could previously be achieved by doing each grouping as a separate query, conjoined by UNION ALLs. Besides being considerably more concise, grouping sets will in many cases be faster, requiring only one scan over the underlying data. The current implementation of grouping sets only supports using sorting for input. Individual sets that share a sort order are computed in one pass. If there are sets that don't share a sort order, additional sort & aggregation steps are performed. These additional passes are sourced by the previous sort step; thus avoiding repeated scans of the source data. The code is structured in a way that adding support for purely using hash aggregation or a mix of hashing and sorting is possible. Sorting was chosen to be supported first, as it is the most generic method of implementation. Instead of, as in an earlier versions of the patch, representing the chain of sort and aggregation steps as full blown planner and executor nodes, all but the first sort are performed inside the aggregation node itself. This avoids the need to do some unusual gymnastics to handle having to return aggregated and non-aggregated tuples from underlying nodes, as well as having to shut down underlying nodes early to limit memory usage. The optimizer still builds Sort/Agg node to describe each phase, but they're not part of the plan tree, but instead additional data for the aggregation node. They're a convenient and preexisting way to describe aggregation and sorting. The first (and possibly only) sort step is still performed as a separate execution step. That retains similarity with existing group by plans, makes rescans fairly simple, avoids very deep plans (leading to slow explains) and easily allows to avoid the sorting step if the underlying data is sorted by other means. A somewhat ugly side of this patch is having to deal with a grammar ambiguity between the new CUBE keyword and the cube extension/functions named cube (and rollup). To avoid breaking existing deployments of the cube extension it has not been renamed, neither has cube been made a reserved keyword. Instead precedence hacking is used to make GROUP BY cube(..) refer to the CUBE grouping sets feature, and not the function cube(). To actually group by a function cube(), unlikely as that might be, the function name has to be quoted. Needs a catversion bump because stored rules may change. Author: Andrew Gierth and Atri Sharma, with contributions from Andres Freund Reviewed-By: Andres Freund, Noah Misch, Tom Lane, Svenne Krap, Tomas Vondra, Erik Rijkers, Marti Raudsepp, Pavel Stehule Discussion: CAOeZVidmVRe2jU6aMk_5qkxnB7dfmPROzM7Ur8JPW5j8Y5X-Lw@mail.gmail.com
2015-05-16 03:40:59 +02:00
if (plan->numCols > 0 || plan->groupingSets)
{
/* The key columns refer to the tlist of the child plan */
ancestors = lcons(astate, ancestors);
Support GROUPING SETS, CUBE and ROLLUP. This SQL standard functionality allows to aggregate data by different GROUP BY clauses at once. Each grouping set returns rows with columns grouped by in other sets set to NULL. This could previously be achieved by doing each grouping as a separate query, conjoined by UNION ALLs. Besides being considerably more concise, grouping sets will in many cases be faster, requiring only one scan over the underlying data. The current implementation of grouping sets only supports using sorting for input. Individual sets that share a sort order are computed in one pass. If there are sets that don't share a sort order, additional sort & aggregation steps are performed. These additional passes are sourced by the previous sort step; thus avoiding repeated scans of the source data. The code is structured in a way that adding support for purely using hash aggregation or a mix of hashing and sorting is possible. Sorting was chosen to be supported first, as it is the most generic method of implementation. Instead of, as in an earlier versions of the patch, representing the chain of sort and aggregation steps as full blown planner and executor nodes, all but the first sort are performed inside the aggregation node itself. This avoids the need to do some unusual gymnastics to handle having to return aggregated and non-aggregated tuples from underlying nodes, as well as having to shut down underlying nodes early to limit memory usage. The optimizer still builds Sort/Agg node to describe each phase, but they're not part of the plan tree, but instead additional data for the aggregation node. They're a convenient and preexisting way to describe aggregation and sorting. The first (and possibly only) sort step is still performed as a separate execution step. That retains similarity with existing group by plans, makes rescans fairly simple, avoids very deep plans (leading to slow explains) and easily allows to avoid the sorting step if the underlying data is sorted by other means. A somewhat ugly side of this patch is having to deal with a grammar ambiguity between the new CUBE keyword and the cube extension/functions named cube (and rollup). To avoid breaking existing deployments of the cube extension it has not been renamed, neither has cube been made a reserved keyword. Instead precedence hacking is used to make GROUP BY cube(..) refer to the CUBE grouping sets feature, and not the function cube(). To actually group by a function cube(), unlikely as that might be, the function name has to be quoted. Needs a catversion bump because stored rules may change. Author: Andrew Gierth and Atri Sharma, with contributions from Andres Freund Reviewed-By: Andres Freund, Noah Misch, Tom Lane, Svenne Krap, Tomas Vondra, Erik Rijkers, Marti Raudsepp, Pavel Stehule Discussion: CAOeZVidmVRe2jU6aMk_5qkxnB7dfmPROzM7Ur8JPW5j8Y5X-Lw@mail.gmail.com
2015-05-16 03:40:59 +02:00
if (plan->groupingSets)
show_grouping_sets(outerPlanState(astate), plan, ancestors, es);
else
show_sort_group_keys(outerPlanState(astate), "Group Key",
plan->numCols, plan->grpColIdx,
NULL, NULL, NULL,
ancestors, es);
ancestors = list_delete_first(ancestors);
}
}
Support GROUPING SETS, CUBE and ROLLUP. This SQL standard functionality allows to aggregate data by different GROUP BY clauses at once. Each grouping set returns rows with columns grouped by in other sets set to NULL. This could previously be achieved by doing each grouping as a separate query, conjoined by UNION ALLs. Besides being considerably more concise, grouping sets will in many cases be faster, requiring only one scan over the underlying data. The current implementation of grouping sets only supports using sorting for input. Individual sets that share a sort order are computed in one pass. If there are sets that don't share a sort order, additional sort & aggregation steps are performed. These additional passes are sourced by the previous sort step; thus avoiding repeated scans of the source data. The code is structured in a way that adding support for purely using hash aggregation or a mix of hashing and sorting is possible. Sorting was chosen to be supported first, as it is the most generic method of implementation. Instead of, as in an earlier versions of the patch, representing the chain of sort and aggregation steps as full blown planner and executor nodes, all but the first sort are performed inside the aggregation node itself. This avoids the need to do some unusual gymnastics to handle having to return aggregated and non-aggregated tuples from underlying nodes, as well as having to shut down underlying nodes early to limit memory usage. The optimizer still builds Sort/Agg node to describe each phase, but they're not part of the plan tree, but instead additional data for the aggregation node. They're a convenient and preexisting way to describe aggregation and sorting. The first (and possibly only) sort step is still performed as a separate execution step. That retains similarity with existing group by plans, makes rescans fairly simple, avoids very deep plans (leading to slow explains) and easily allows to avoid the sorting step if the underlying data is sorted by other means. A somewhat ugly side of this patch is having to deal with a grammar ambiguity between the new CUBE keyword and the cube extension/functions named cube (and rollup). To avoid breaking existing deployments of the cube extension it has not been renamed, neither has cube been made a reserved keyword. Instead precedence hacking is used to make GROUP BY cube(..) refer to the CUBE grouping sets feature, and not the function cube(). To actually group by a function cube(), unlikely as that might be, the function name has to be quoted. Needs a catversion bump because stored rules may change. Author: Andrew Gierth and Atri Sharma, with contributions from Andres Freund Reviewed-By: Andres Freund, Noah Misch, Tom Lane, Svenne Krap, Tomas Vondra, Erik Rijkers, Marti Raudsepp, Pavel Stehule Discussion: CAOeZVidmVRe2jU6aMk_5qkxnB7dfmPROzM7Ur8JPW5j8Y5X-Lw@mail.gmail.com
2015-05-16 03:40:59 +02:00
static void
show_grouping_sets(PlanState *planstate, Agg *agg,
List *ancestors, ExplainState *es)
{
List *context;
bool useprefix;
ListCell *lc;
/* Set up deparsing context */
context = set_deparse_context_planstate(es->deparse_cxt,
(Node *) planstate,
ancestors);
useprefix = (list_length(es->rtable) > 1 || es->verbose);
ExplainOpenGroup("Grouping Sets", "Grouping Sets", false, es);
show_grouping_set_keys(planstate, agg, NULL,
context, useprefix, ancestors, es);
foreach(lc, agg->chain)
{
2015-05-24 03:35:49 +02:00
Agg *aggnode = lfirst(lc);
Sort *sortnode = (Sort *) aggnode->plan.lefttree;
Support GROUPING SETS, CUBE and ROLLUP. This SQL standard functionality allows to aggregate data by different GROUP BY clauses at once. Each grouping set returns rows with columns grouped by in other sets set to NULL. This could previously be achieved by doing each grouping as a separate query, conjoined by UNION ALLs. Besides being considerably more concise, grouping sets will in many cases be faster, requiring only one scan over the underlying data. The current implementation of grouping sets only supports using sorting for input. Individual sets that share a sort order are computed in one pass. If there are sets that don't share a sort order, additional sort & aggregation steps are performed. These additional passes are sourced by the previous sort step; thus avoiding repeated scans of the source data. The code is structured in a way that adding support for purely using hash aggregation or a mix of hashing and sorting is possible. Sorting was chosen to be supported first, as it is the most generic method of implementation. Instead of, as in an earlier versions of the patch, representing the chain of sort and aggregation steps as full blown planner and executor nodes, all but the first sort are performed inside the aggregation node itself. This avoids the need to do some unusual gymnastics to handle having to return aggregated and non-aggregated tuples from underlying nodes, as well as having to shut down underlying nodes early to limit memory usage. The optimizer still builds Sort/Agg node to describe each phase, but they're not part of the plan tree, but instead additional data for the aggregation node. They're a convenient and preexisting way to describe aggregation and sorting. The first (and possibly only) sort step is still performed as a separate execution step. That retains similarity with existing group by plans, makes rescans fairly simple, avoids very deep plans (leading to slow explains) and easily allows to avoid the sorting step if the underlying data is sorted by other means. A somewhat ugly side of this patch is having to deal with a grammar ambiguity between the new CUBE keyword and the cube extension/functions named cube (and rollup). To avoid breaking existing deployments of the cube extension it has not been renamed, neither has cube been made a reserved keyword. Instead precedence hacking is used to make GROUP BY cube(..) refer to the CUBE grouping sets feature, and not the function cube(). To actually group by a function cube(), unlikely as that might be, the function name has to be quoted. Needs a catversion bump because stored rules may change. Author: Andrew Gierth and Atri Sharma, with contributions from Andres Freund Reviewed-By: Andres Freund, Noah Misch, Tom Lane, Svenne Krap, Tomas Vondra, Erik Rijkers, Marti Raudsepp, Pavel Stehule Discussion: CAOeZVidmVRe2jU6aMk_5qkxnB7dfmPROzM7Ur8JPW5j8Y5X-Lw@mail.gmail.com
2015-05-16 03:40:59 +02:00
show_grouping_set_keys(planstate, aggnode, sortnode,
context, useprefix, ancestors, es);
}
ExplainCloseGroup("Grouping Sets", "Grouping Sets", false, es);
}
static void
show_grouping_set_keys(PlanState *planstate,
Agg *aggnode, Sort *sortnode,
List *context, bool useprefix,
List *ancestors, ExplainState *es)
{
Plan *plan = planstate->plan;
char *exprstr;
ListCell *lc;
List *gsets = aggnode->groupingSets;
AttrNumber *keycols = aggnode->grpColIdx;
const char *keyname;
const char *keysetname;
if (aggnode->aggstrategy == AGG_HASHED || aggnode->aggstrategy == AGG_MIXED)
{
keyname = "Hash Key";
keysetname = "Hash Keys";
}
else
{
keyname = "Group Key";
keysetname = "Group Keys";
}
Support GROUPING SETS, CUBE and ROLLUP. This SQL standard functionality allows to aggregate data by different GROUP BY clauses at once. Each grouping set returns rows with columns grouped by in other sets set to NULL. This could previously be achieved by doing each grouping as a separate query, conjoined by UNION ALLs. Besides being considerably more concise, grouping sets will in many cases be faster, requiring only one scan over the underlying data. The current implementation of grouping sets only supports using sorting for input. Individual sets that share a sort order are computed in one pass. If there are sets that don't share a sort order, additional sort & aggregation steps are performed. These additional passes are sourced by the previous sort step; thus avoiding repeated scans of the source data. The code is structured in a way that adding support for purely using hash aggregation or a mix of hashing and sorting is possible. Sorting was chosen to be supported first, as it is the most generic method of implementation. Instead of, as in an earlier versions of the patch, representing the chain of sort and aggregation steps as full blown planner and executor nodes, all but the first sort are performed inside the aggregation node itself. This avoids the need to do some unusual gymnastics to handle having to return aggregated and non-aggregated tuples from underlying nodes, as well as having to shut down underlying nodes early to limit memory usage. The optimizer still builds Sort/Agg node to describe each phase, but they're not part of the plan tree, but instead additional data for the aggregation node. They're a convenient and preexisting way to describe aggregation and sorting. The first (and possibly only) sort step is still performed as a separate execution step. That retains similarity with existing group by plans, makes rescans fairly simple, avoids very deep plans (leading to slow explains) and easily allows to avoid the sorting step if the underlying data is sorted by other means. A somewhat ugly side of this patch is having to deal with a grammar ambiguity between the new CUBE keyword and the cube extension/functions named cube (and rollup). To avoid breaking existing deployments of the cube extension it has not been renamed, neither has cube been made a reserved keyword. Instead precedence hacking is used to make GROUP BY cube(..) refer to the CUBE grouping sets feature, and not the function cube(). To actually group by a function cube(), unlikely as that might be, the function name has to be quoted. Needs a catversion bump because stored rules may change. Author: Andrew Gierth and Atri Sharma, with contributions from Andres Freund Reviewed-By: Andres Freund, Noah Misch, Tom Lane, Svenne Krap, Tomas Vondra, Erik Rijkers, Marti Raudsepp, Pavel Stehule Discussion: CAOeZVidmVRe2jU6aMk_5qkxnB7dfmPROzM7Ur8JPW5j8Y5X-Lw@mail.gmail.com
2015-05-16 03:40:59 +02:00
ExplainOpenGroup("Grouping Set", NULL, true, es);
if (sortnode)
{
show_sort_group_keys(planstate, "Sort Key",
sortnode->numCols, sortnode->sortColIdx,
sortnode->sortOperators, sortnode->collations,
sortnode->nullsFirst,
ancestors, es);
if (es->format == EXPLAIN_FORMAT_TEXT)
es->indent++;
}
ExplainOpenGroup(keysetname, keysetname, false, es);
Support GROUPING SETS, CUBE and ROLLUP. This SQL standard functionality allows to aggregate data by different GROUP BY clauses at once. Each grouping set returns rows with columns grouped by in other sets set to NULL. This could previously be achieved by doing each grouping as a separate query, conjoined by UNION ALLs. Besides being considerably more concise, grouping sets will in many cases be faster, requiring only one scan over the underlying data. The current implementation of grouping sets only supports using sorting for input. Individual sets that share a sort order are computed in one pass. If there are sets that don't share a sort order, additional sort & aggregation steps are performed. These additional passes are sourced by the previous sort step; thus avoiding repeated scans of the source data. The code is structured in a way that adding support for purely using hash aggregation or a mix of hashing and sorting is possible. Sorting was chosen to be supported first, as it is the most generic method of implementation. Instead of, as in an earlier versions of the patch, representing the chain of sort and aggregation steps as full blown planner and executor nodes, all but the first sort are performed inside the aggregation node itself. This avoids the need to do some unusual gymnastics to handle having to return aggregated and non-aggregated tuples from underlying nodes, as well as having to shut down underlying nodes early to limit memory usage. The optimizer still builds Sort/Agg node to describe each phase, but they're not part of the plan tree, but instead additional data for the aggregation node. They're a convenient and preexisting way to describe aggregation and sorting. The first (and possibly only) sort step is still performed as a separate execution step. That retains similarity with existing group by plans, makes rescans fairly simple, avoids very deep plans (leading to slow explains) and easily allows to avoid the sorting step if the underlying data is sorted by other means. A somewhat ugly side of this patch is having to deal with a grammar ambiguity between the new CUBE keyword and the cube extension/functions named cube (and rollup). To avoid breaking existing deployments of the cube extension it has not been renamed, neither has cube been made a reserved keyword. Instead precedence hacking is used to make GROUP BY cube(..) refer to the CUBE grouping sets feature, and not the function cube(). To actually group by a function cube(), unlikely as that might be, the function name has to be quoted. Needs a catversion bump because stored rules may change. Author: Andrew Gierth and Atri Sharma, with contributions from Andres Freund Reviewed-By: Andres Freund, Noah Misch, Tom Lane, Svenne Krap, Tomas Vondra, Erik Rijkers, Marti Raudsepp, Pavel Stehule Discussion: CAOeZVidmVRe2jU6aMk_5qkxnB7dfmPROzM7Ur8JPW5j8Y5X-Lw@mail.gmail.com
2015-05-16 03:40:59 +02:00
foreach(lc, gsets)
{
List *result = NIL;
ListCell *lc2;
foreach(lc2, (List *) lfirst(lc))
{
Index i = lfirst_int(lc2);
AttrNumber keyresno = keycols[i];
TargetEntry *target = get_tle_by_resno(plan->targetlist,
keyresno);
if (!target)
elog(ERROR, "no tlist entry for key %d", keyresno);
/* Deparse the expression, showing any top-level cast */
exprstr = deparse_expression((Node *) target->expr, context,
useprefix, true);
result = lappend(result, exprstr);
}
if (!result && es->format == EXPLAIN_FORMAT_TEXT)
ExplainPropertyText(keyname, "()", es);
Support GROUPING SETS, CUBE and ROLLUP. This SQL standard functionality allows to aggregate data by different GROUP BY clauses at once. Each grouping set returns rows with columns grouped by in other sets set to NULL. This could previously be achieved by doing each grouping as a separate query, conjoined by UNION ALLs. Besides being considerably more concise, grouping sets will in many cases be faster, requiring only one scan over the underlying data. The current implementation of grouping sets only supports using sorting for input. Individual sets that share a sort order are computed in one pass. If there are sets that don't share a sort order, additional sort & aggregation steps are performed. These additional passes are sourced by the previous sort step; thus avoiding repeated scans of the source data. The code is structured in a way that adding support for purely using hash aggregation or a mix of hashing and sorting is possible. Sorting was chosen to be supported first, as it is the most generic method of implementation. Instead of, as in an earlier versions of the patch, representing the chain of sort and aggregation steps as full blown planner and executor nodes, all but the first sort are performed inside the aggregation node itself. This avoids the need to do some unusual gymnastics to handle having to return aggregated and non-aggregated tuples from underlying nodes, as well as having to shut down underlying nodes early to limit memory usage. The optimizer still builds Sort/Agg node to describe each phase, but they're not part of the plan tree, but instead additional data for the aggregation node. They're a convenient and preexisting way to describe aggregation and sorting. The first (and possibly only) sort step is still performed as a separate execution step. That retains similarity with existing group by plans, makes rescans fairly simple, avoids very deep plans (leading to slow explains) and easily allows to avoid the sorting step if the underlying data is sorted by other means. A somewhat ugly side of this patch is having to deal with a grammar ambiguity between the new CUBE keyword and the cube extension/functions named cube (and rollup). To avoid breaking existing deployments of the cube extension it has not been renamed, neither has cube been made a reserved keyword. Instead precedence hacking is used to make GROUP BY cube(..) refer to the CUBE grouping sets feature, and not the function cube(). To actually group by a function cube(), unlikely as that might be, the function name has to be quoted. Needs a catversion bump because stored rules may change. Author: Andrew Gierth and Atri Sharma, with contributions from Andres Freund Reviewed-By: Andres Freund, Noah Misch, Tom Lane, Svenne Krap, Tomas Vondra, Erik Rijkers, Marti Raudsepp, Pavel Stehule Discussion: CAOeZVidmVRe2jU6aMk_5qkxnB7dfmPROzM7Ur8JPW5j8Y5X-Lw@mail.gmail.com
2015-05-16 03:40:59 +02:00
else
ExplainPropertyListNested(keyname, result, es);
Support GROUPING SETS, CUBE and ROLLUP. This SQL standard functionality allows to aggregate data by different GROUP BY clauses at once. Each grouping set returns rows with columns grouped by in other sets set to NULL. This could previously be achieved by doing each grouping as a separate query, conjoined by UNION ALLs. Besides being considerably more concise, grouping sets will in many cases be faster, requiring only one scan over the underlying data. The current implementation of grouping sets only supports using sorting for input. Individual sets that share a sort order are computed in one pass. If there are sets that don't share a sort order, additional sort & aggregation steps are performed. These additional passes are sourced by the previous sort step; thus avoiding repeated scans of the source data. The code is structured in a way that adding support for purely using hash aggregation or a mix of hashing and sorting is possible. Sorting was chosen to be supported first, as it is the most generic method of implementation. Instead of, as in an earlier versions of the patch, representing the chain of sort and aggregation steps as full blown planner and executor nodes, all but the first sort are performed inside the aggregation node itself. This avoids the need to do some unusual gymnastics to handle having to return aggregated and non-aggregated tuples from underlying nodes, as well as having to shut down underlying nodes early to limit memory usage. The optimizer still builds Sort/Agg node to describe each phase, but they're not part of the plan tree, but instead additional data for the aggregation node. They're a convenient and preexisting way to describe aggregation and sorting. The first (and possibly only) sort step is still performed as a separate execution step. That retains similarity with existing group by plans, makes rescans fairly simple, avoids very deep plans (leading to slow explains) and easily allows to avoid the sorting step if the underlying data is sorted by other means. A somewhat ugly side of this patch is having to deal with a grammar ambiguity between the new CUBE keyword and the cube extension/functions named cube (and rollup). To avoid breaking existing deployments of the cube extension it has not been renamed, neither has cube been made a reserved keyword. Instead precedence hacking is used to make GROUP BY cube(..) refer to the CUBE grouping sets feature, and not the function cube(). To actually group by a function cube(), unlikely as that might be, the function name has to be quoted. Needs a catversion bump because stored rules may change. Author: Andrew Gierth and Atri Sharma, with contributions from Andres Freund Reviewed-By: Andres Freund, Noah Misch, Tom Lane, Svenne Krap, Tomas Vondra, Erik Rijkers, Marti Raudsepp, Pavel Stehule Discussion: CAOeZVidmVRe2jU6aMk_5qkxnB7dfmPROzM7Ur8JPW5j8Y5X-Lw@mail.gmail.com
2015-05-16 03:40:59 +02:00
}
ExplainCloseGroup(keysetname, keysetname, false, es);
Support GROUPING SETS, CUBE and ROLLUP. This SQL standard functionality allows to aggregate data by different GROUP BY clauses at once. Each grouping set returns rows with columns grouped by in other sets set to NULL. This could previously be achieved by doing each grouping as a separate query, conjoined by UNION ALLs. Besides being considerably more concise, grouping sets will in many cases be faster, requiring only one scan over the underlying data. The current implementation of grouping sets only supports using sorting for input. Individual sets that share a sort order are computed in one pass. If there are sets that don't share a sort order, additional sort & aggregation steps are performed. These additional passes are sourced by the previous sort step; thus avoiding repeated scans of the source data. The code is structured in a way that adding support for purely using hash aggregation or a mix of hashing and sorting is possible. Sorting was chosen to be supported first, as it is the most generic method of implementation. Instead of, as in an earlier versions of the patch, representing the chain of sort and aggregation steps as full blown planner and executor nodes, all but the first sort are performed inside the aggregation node itself. This avoids the need to do some unusual gymnastics to handle having to return aggregated and non-aggregated tuples from underlying nodes, as well as having to shut down underlying nodes early to limit memory usage. The optimizer still builds Sort/Agg node to describe each phase, but they're not part of the plan tree, but instead additional data for the aggregation node. They're a convenient and preexisting way to describe aggregation and sorting. The first (and possibly only) sort step is still performed as a separate execution step. That retains similarity with existing group by plans, makes rescans fairly simple, avoids very deep plans (leading to slow explains) and easily allows to avoid the sorting step if the underlying data is sorted by other means. A somewhat ugly side of this patch is having to deal with a grammar ambiguity between the new CUBE keyword and the cube extension/functions named cube (and rollup). To avoid breaking existing deployments of the cube extension it has not been renamed, neither has cube been made a reserved keyword. Instead precedence hacking is used to make GROUP BY cube(..) refer to the CUBE grouping sets feature, and not the function cube(). To actually group by a function cube(), unlikely as that might be, the function name has to be quoted. Needs a catversion bump because stored rules may change. Author: Andrew Gierth and Atri Sharma, with contributions from Andres Freund Reviewed-By: Andres Freund, Noah Misch, Tom Lane, Svenne Krap, Tomas Vondra, Erik Rijkers, Marti Raudsepp, Pavel Stehule Discussion: CAOeZVidmVRe2jU6aMk_5qkxnB7dfmPROzM7Ur8JPW5j8Y5X-Lw@mail.gmail.com
2015-05-16 03:40:59 +02:00
if (sortnode && es->format == EXPLAIN_FORMAT_TEXT)
es->indent--;
ExplainCloseGroup("Grouping Set", NULL, true, es);
}
/*
* Show the grouping keys for a Group node.
*/
static void
show_group_keys(GroupState *gstate, List *ancestors,
ExplainState *es)
{
Group *plan = (Group *) gstate->ss.ps.plan;
/* The key columns refer to the tlist of the child plan */
ancestors = lcons(gstate, ancestors);
show_sort_group_keys(outerPlanState(gstate), "Group Key",
plan->numCols, plan->grpColIdx,
NULL, NULL, NULL,
ancestors, es);
ancestors = list_delete_first(ancestors);
}
/*
* Common code to show sort/group keys, which are represented in plan nodes
* as arrays of targetlist indexes. If it's a sort key rather than a group
* key, also pass sort operators/collations/nullsFirst arrays.
*/
static void
show_sort_group_keys(PlanState *planstate, const char *qlabel,
int nkeys, AttrNumber *keycols,
Oid *sortOperators, Oid *collations, bool *nullsFirst,
List *ancestors, ExplainState *es)
{
Plan *plan = planstate->plan;
List *context;
List *result = NIL;
StringInfoData sortkeybuf;
bool useprefix;
int keyno;
if (nkeys <= 0)
return;
initStringInfo(&sortkeybuf);
/* Set up deparsing context */
context = set_deparse_context_planstate(es->deparse_cxt,
(Node *) planstate,
ancestors);
useprefix = (list_length(es->rtable) > 1 || es->verbose);
for (keyno = 0; keyno < nkeys; keyno++)
{
/* find key expression in tlist */
AttrNumber keyresno = keycols[keyno];
TargetEntry *target = get_tle_by_resno(plan->targetlist,
keyresno);
char *exprstr;
if (!target)
elog(ERROR, "no tlist entry for key %d", keyresno);
/* Deparse the expression, showing any top-level cast */
exprstr = deparse_expression((Node *) target->expr, context,
useprefix, true);
resetStringInfo(&sortkeybuf);
appendStringInfoString(&sortkeybuf, exprstr);
/* Append sort order information, if relevant */
if (sortOperators != NULL)
show_sortorder_options(&sortkeybuf,
(Node *) target->expr,
sortOperators[keyno],
collations[keyno],
nullsFirst[keyno]);
/* Emit one property-list item per sort key */
result = lappend(result, pstrdup(sortkeybuf.data));
}
ExplainPropertyList(qlabel, result, es);
}
/*
* Append nondefault characteristics of the sort ordering of a column to buf
* (collation, direction, NULLS FIRST/LAST)
*/
static void
show_sortorder_options(StringInfo buf, Node *sortexpr,
Oid sortOperator, Oid collation, bool nullsFirst)
{
Oid sortcoltype = exprType(sortexpr);
bool reverse = false;
TypeCacheEntry *typentry;
typentry = lookup_type_cache(sortcoltype,
TYPECACHE_LT_OPR | TYPECACHE_GT_OPR);
/*
* Print COLLATE if it's not default. There are some cases where this is
* redundant, eg if expression is a column whose declared collation is
* that collation, but it's hard to distinguish that here.
*/
if (OidIsValid(collation) && collation != DEFAULT_COLLATION_OID)
{
char *collname = get_collation_name(collation);
if (collname == NULL)
elog(ERROR, "cache lookup failed for collation %u", collation);
appendStringInfo(buf, " COLLATE %s", quote_identifier(collname));
}
/* Print direction if not ASC, or USING if non-default sort operator */
if (sortOperator == typentry->gt_opr)
{
appendStringInfoString(buf, " DESC");
reverse = true;
}
else if (sortOperator != typentry->lt_opr)
{
char *opname = get_opname(sortOperator);
if (opname == NULL)
elog(ERROR, "cache lookup failed for operator %u", sortOperator);
appendStringInfo(buf, " USING %s", opname);
/* Determine whether operator would be considered ASC or DESC */
(void) get_equality_op_for_ordering_op(sortOperator, &reverse);
}
/* Add NULLS FIRST/LAST only if it wouldn't be default */
if (nullsFirst && !reverse)
{
appendStringInfoString(buf, " NULLS FIRST");
}
else if (!nullsFirst && reverse)
{
appendStringInfoString(buf, " NULLS LAST");
}
}
Redesign tablesample method API, and do extensive code review. The original implementation of TABLESAMPLE modeled the tablesample method API on index access methods, which wasn't a good choice because, without specialized DDL commands, there's no way to build an extension that can implement a TSM. (Raw inserts into system catalogs are not an acceptable thing to do, because we can't undo them during DROP EXTENSION, nor will pg_upgrade behave sanely.) Instead adopt an API more like procedural language handlers or foreign data wrappers, wherein the only SQL-level support object needed is a single handler function identified by having a special return type. This lets us get rid of the supporting catalog altogether, so that no custom DDL support is needed for the feature. Adjust the API so that it can support non-constant tablesample arguments (the original coding assumed we could evaluate the argument expressions at ExecInitSampleScan time, which is undesirable even if it weren't outright unsafe), and discourage sampling methods from looking at invisible tuples. Make sure that the BERNOULLI and SYSTEM methods are genuinely repeatable within and across queries, as required by the SQL standard, and deal more honestly with methods that can't support that requirement. Make a full code-review pass over the tablesample additions, and fix assorted bugs, omissions, infelicities, and cosmetic issues (such as failure to put the added code stanzas in a consistent ordering). Improve EXPLAIN's output of tablesample plans, too. Back-patch to 9.5 so that we don't have to support the original API in production.
2015-07-25 20:39:00 +02:00
/*
* Show TABLESAMPLE properties
*/
static void
show_tablesample(TableSampleClause *tsc, PlanState *planstate,
List *ancestors, ExplainState *es)
{
List *context;
bool useprefix;
char *method_name;
List *params = NIL;
char *repeatable;
ListCell *lc;
/* Set up deparsing context */
context = set_deparse_context_planstate(es->deparse_cxt,
(Node *) planstate,
ancestors);
useprefix = list_length(es->rtable) > 1;
/* Get the tablesample method name */
method_name = get_func_name(tsc->tsmhandler);
/* Deparse parameter expressions */
foreach(lc, tsc->args)
{
Node *arg = (Node *) lfirst(lc);
params = lappend(params,
deparse_expression(arg, context,
useprefix, false));
}
if (tsc->repeatable)
repeatable = deparse_expression((Node *) tsc->repeatable, context,
useprefix, false);
else
repeatable = NULL;
/* Print results */
if (es->format == EXPLAIN_FORMAT_TEXT)
{
bool first = true;
appendStringInfoSpaces(es->str, es->indent * 2);
appendStringInfo(es->str, "Sampling: %s (", method_name);
foreach(lc, params)
{
if (!first)
appendStringInfoString(es->str, ", ");
appendStringInfoString(es->str, (const char *) lfirst(lc));
first = false;
}
appendStringInfoChar(es->str, ')');
if (repeatable)
appendStringInfo(es->str, " REPEATABLE (%s)", repeatable);
appendStringInfoChar(es->str, '\n');
}
else
{
ExplainPropertyText("Sampling Method", method_name, es);
ExplainPropertyList("Sampling Parameters", params, es);
if (repeatable)
ExplainPropertyText("Repeatable Seed", repeatable, es);
}
}
/*
* If it's EXPLAIN ANALYZE, show tuplesort stats for a sort node
*/
static void
show_sort_info(SortState *sortstate, ExplainState *es)
{
if (!es->analyze)
return;
if (sortstate->sort_Done && sortstate->tuplesortstate != NULL)
{
2010-02-26 03:01:40 +01:00
Tuplesortstate *state = (Tuplesortstate *) sortstate->tuplesortstate;
TuplesortInstrumentation stats;
const char *sortMethod;
const char *spaceType;
long spaceUsed;
tuplesort_get_stats(state, &stats);
sortMethod = tuplesort_method_name(stats.sortMethod);
spaceType = tuplesort_space_type_name(stats.spaceType);
spaceUsed = stats.spaceUsed;
if (es->format == EXPLAIN_FORMAT_TEXT)
{
appendStringInfoSpaces(es->str, es->indent * 2);
appendStringInfo(es->str, "Sort Method: %s %s: %ldkB\n",
sortMethod, spaceType, spaceUsed);
}
else
{
ExplainPropertyText("Sort Method", sortMethod, es);
ExplainPropertyLong("Sort Space Used", spaceUsed, es);
ExplainPropertyText("Sort Space Type", spaceType, es);
}
}
if (sortstate->shared_info != NULL)
{
int n;
bool opened_group = false;
for (n = 0; n < sortstate->shared_info->num_workers; n++)
{
TuplesortInstrumentation *sinstrument;
const char *sortMethod;
const char *spaceType;
long spaceUsed;
sinstrument = &sortstate->shared_info->sinstrument[n];
if (sinstrument->sortMethod == SORT_TYPE_STILL_IN_PROGRESS)
continue; /* ignore any unfilled slots */
sortMethod = tuplesort_method_name(sinstrument->sortMethod);
spaceType = tuplesort_space_type_name(sinstrument->spaceType);
spaceUsed = sinstrument->spaceUsed;
if (es->format == EXPLAIN_FORMAT_TEXT)
{
appendStringInfoSpaces(es->str, es->indent * 2);
appendStringInfo(es->str,
"Worker %d: Sort Method: %s %s: %ldkB\n",
n, sortMethod, spaceType, spaceUsed);
}
else
{
if (!opened_group)
{
ExplainOpenGroup("Workers", "Workers", false, es);
opened_group = true;
}
ExplainOpenGroup("Worker", NULL, true, es);
ExplainPropertyInteger("Worker Number", n, es);
ExplainPropertyText("Sort Method", sortMethod, es);
ExplainPropertyLong("Sort Space Used", spaceUsed, es);
ExplainPropertyText("Sort Space Type", spaceType, es);
ExplainCloseGroup("Worker", NULL, true, es);
}
}
if (opened_group)
ExplainCloseGroup("Workers", "Workers", false, es);
}
}
/*
* Show information on hash buckets/batches.
*/
static void
show_hash_info(HashState *hashstate, ExplainState *es)
{
HashJoinTable hashtable;
hashtable = hashstate->hashtable;
if (hashtable)
{
2010-02-26 03:01:40 +01:00
long spacePeakKb = (hashtable->spacePeak + 1023) / 1024;
if (es->format != EXPLAIN_FORMAT_TEXT)
{
ExplainPropertyLong("Hash Buckets", hashtable->nbuckets, es);
ExplainPropertyLong("Original Hash Buckets",
hashtable->nbuckets_original, es);
ExplainPropertyLong("Hash Batches", hashtable->nbatch, es);
ExplainPropertyLong("Original Hash Batches",
hashtable->nbatch_original, es);
ExplainPropertyLong("Peak Memory Usage", spacePeakKb, es);
}
else if (hashtable->nbatch_original != hashtable->nbatch ||
hashtable->nbuckets_original != hashtable->nbuckets)
{
appendStringInfoSpaces(es->str, es->indent * 2);
appendStringInfo(es->str,
"Buckets: %d (originally %d) Batches: %d (originally %d) Memory Usage: %ldkB\n",
hashtable->nbuckets,
hashtable->nbuckets_original,
hashtable->nbatch,
hashtable->nbatch_original,
spacePeakKb);
}
else
{
appendStringInfoSpaces(es->str, es->indent * 2);
appendStringInfo(es->str,
"Buckets: %d Batches: %d Memory Usage: %ldkB\n",
hashtable->nbuckets, hashtable->nbatch,
spacePeakKb);
}
}
}
/*
* If it's EXPLAIN ANALYZE, show exact/lossy pages for a BitmapHeapScan node
*/
static void
show_tidbitmap_info(BitmapHeapScanState *planstate, ExplainState *es)
{
if (es->format != EXPLAIN_FORMAT_TEXT)
{
ExplainPropertyLong("Exact Heap Blocks", planstate->exact_pages, es);
ExplainPropertyLong("Lossy Heap Blocks", planstate->lossy_pages, es);
}
else
{
if (planstate->exact_pages > 0 || planstate->lossy_pages > 0)
{
appendStringInfoSpaces(es->str, es->indent * 2);
appendStringInfoString(es->str, "Heap Blocks:");
if (planstate->exact_pages > 0)
appendStringInfo(es->str, " exact=%ld", planstate->exact_pages);
if (planstate->lossy_pages > 0)
appendStringInfo(es->str, " lossy=%ld", planstate->lossy_pages);
appendStringInfoChar(es->str, '\n');
}
}
}
/*
* If it's EXPLAIN ANALYZE, show instrumentation information for a plan node
*
* "which" identifies which instrumentation counter to print
*/
static void
show_instrumentation_count(const char *qlabel, int which,
PlanState *planstate, ExplainState *es)
{
double nfiltered;
double nloops;
if (!es->analyze || !planstate->instrument)
return;
if (which == 2)
nfiltered = planstate->instrument->nfiltered2;
else
nfiltered = planstate->instrument->nfiltered1;
nloops = planstate->instrument->nloops;
/* In text mode, suppress zero counts; they're not interesting enough */
if (nfiltered > 0 || es->format != EXPLAIN_FORMAT_TEXT)
{
if (nloops > 0)
ExplainPropertyFloat(qlabel, nfiltered / nloops, 0, es);
else
ExplainPropertyFloat(qlabel, 0.0, 0, es);
}
}
/*
* Show extra information for a ForeignScan node.
*/
static void
show_foreignscan_info(ForeignScanState *fsstate, ExplainState *es)
{
FdwRoutine *fdwroutine = fsstate->fdwroutine;
/* Let the FDW emit whatever fields it wants */
if (((ForeignScan *) fsstate->ss.ps.plan)->operation != CMD_SELECT)
{
if (fdwroutine->ExplainDirectModify != NULL)
fdwroutine->ExplainDirectModify(fsstate, es);
}
else
{
if (fdwroutine->ExplainForeignScan != NULL)
fdwroutine->ExplainForeignScan(fsstate, es);
}
}
/*
* Fetch the name of an index in an EXPLAIN
*
* We allow plugins to get control here so that plans involving hypothetical
* indexes can be explained.
*/
static const char *
explain_get_index_name(Oid indexId)
{
2007-11-15 22:14:46 +01:00
const char *result;
if (explain_get_index_name_hook)
result = (*explain_get_index_name_hook) (indexId);
else
result = NULL;
if (result == NULL)
{
/* default behavior: look in the catalogs and quote it */
result = get_rel_name(indexId);
if (result == NULL)
elog(ERROR, "cache lookup failed for index %u", indexId);
result = quote_identifier(result);
}
return result;
}
/*
* Show buffer usage details.
*/
static void
show_buffer_usage(ExplainState *es, const BufferUsage *usage)
{
if (es->format == EXPLAIN_FORMAT_TEXT)
{
bool has_shared = (usage->shared_blks_hit > 0 ||
usage->shared_blks_read > 0 ||
usage->shared_blks_dirtied > 0 ||
usage->shared_blks_written > 0);
bool has_local = (usage->local_blks_hit > 0 ||
usage->local_blks_read > 0 ||
usage->local_blks_dirtied > 0 ||
usage->local_blks_written > 0);
bool has_temp = (usage->temp_blks_read > 0 ||
usage->temp_blks_written > 0);
bool has_timing = (!INSTR_TIME_IS_ZERO(usage->blk_read_time) ||
!INSTR_TIME_IS_ZERO(usage->blk_write_time));
/* Show only positive counter values. */
if (has_shared || has_local || has_temp)
{
appendStringInfoSpaces(es->str, es->indent * 2);
appendStringInfoString(es->str, "Buffers:");
if (has_shared)
{
appendStringInfoString(es->str, " shared");
if (usage->shared_blks_hit > 0)
appendStringInfo(es->str, " hit=%ld",
usage->shared_blks_hit);
if (usage->shared_blks_read > 0)
appendStringInfo(es->str, " read=%ld",
usage->shared_blks_read);
if (usage->shared_blks_dirtied > 0)
appendStringInfo(es->str, " dirtied=%ld",
usage->shared_blks_dirtied);
if (usage->shared_blks_written > 0)
appendStringInfo(es->str, " written=%ld",
usage->shared_blks_written);
if (has_local || has_temp)
appendStringInfoChar(es->str, ',');
}
if (has_local)
{
appendStringInfoString(es->str, " local");
if (usage->local_blks_hit > 0)
appendStringInfo(es->str, " hit=%ld",
usage->local_blks_hit);
if (usage->local_blks_read > 0)
appendStringInfo(es->str, " read=%ld",
usage->local_blks_read);
if (usage->local_blks_dirtied > 0)
appendStringInfo(es->str, " dirtied=%ld",
usage->local_blks_dirtied);
if (usage->local_blks_written > 0)
appendStringInfo(es->str, " written=%ld",
usage->local_blks_written);
if (has_temp)
appendStringInfoChar(es->str, ',');
}
if (has_temp)
{
appendStringInfoString(es->str, " temp");
if (usage->temp_blks_read > 0)
appendStringInfo(es->str, " read=%ld",
usage->temp_blks_read);
if (usage->temp_blks_written > 0)
appendStringInfo(es->str, " written=%ld",
usage->temp_blks_written);
}
appendStringInfoChar(es->str, '\n');
}
/* As above, show only positive counter values. */
if (has_timing)
{
appendStringInfoSpaces(es->str, es->indent * 2);
appendStringInfoString(es->str, "I/O Timings:");
if (!INSTR_TIME_IS_ZERO(usage->blk_read_time))
appendStringInfo(es->str, " read=%0.3f",
INSTR_TIME_GET_MILLISEC(usage->blk_read_time));
if (!INSTR_TIME_IS_ZERO(usage->blk_write_time))
appendStringInfo(es->str, " write=%0.3f",
INSTR_TIME_GET_MILLISEC(usage->blk_write_time));
appendStringInfoChar(es->str, '\n');
}
}
else
{
ExplainPropertyLong("Shared Hit Blocks", usage->shared_blks_hit, es);
ExplainPropertyLong("Shared Read Blocks", usage->shared_blks_read, es);
ExplainPropertyLong("Shared Dirtied Blocks", usage->shared_blks_dirtied, es);
ExplainPropertyLong("Shared Written Blocks", usage->shared_blks_written, es);
ExplainPropertyLong("Local Hit Blocks", usage->local_blks_hit, es);
ExplainPropertyLong("Local Read Blocks", usage->local_blks_read, es);
ExplainPropertyLong("Local Dirtied Blocks", usage->local_blks_dirtied, es);
ExplainPropertyLong("Local Written Blocks", usage->local_blks_written, es);
ExplainPropertyLong("Temp Read Blocks", usage->temp_blks_read, es);
ExplainPropertyLong("Temp Written Blocks", usage->temp_blks_written, es);
if (track_io_timing)
{
ExplainPropertyFloat("I/O Read Time", INSTR_TIME_GET_MILLISEC(usage->blk_read_time), 3, es);
ExplainPropertyFloat("I/O Write Time", INSTR_TIME_GET_MILLISEC(usage->blk_write_time), 3, es);
}
}
}
/*
* Add some additional details about an IndexScan or IndexOnlyScan
*/
static void
ExplainIndexScanDetails(Oid indexid, ScanDirection indexorderdir,
ExplainState *es)
{
const char *indexname = explain_get_index_name(indexid);
if (es->format == EXPLAIN_FORMAT_TEXT)
{
if (ScanDirectionIsBackward(indexorderdir))
appendStringInfoString(es->str, " Backward");
appendStringInfo(es->str, " using %s", indexname);
}
else
{
const char *scandir;
switch (indexorderdir)
{
case BackwardScanDirection:
scandir = "Backward";
break;
case NoMovementScanDirection:
scandir = "NoMovement";
break;
case ForwardScanDirection:
scandir = "Forward";
break;
default:
scandir = "???";
break;
}
ExplainPropertyText("Scan Direction", scandir, es);
ExplainPropertyText("Index Name", indexname, es);
}
}
/*
* Show the target of a Scan node
*/
static void
ExplainScanTarget(Scan *plan, ExplainState *es)
{
ExplainTargetRel((Plan *) plan, plan->scanrelid, es);
}
/*
* Show the target of a ModifyTable node
Allow foreign tables to participate in inheritance. Foreign tables can now be inheritance children, or parents. Much of the system was already ready for this, but we had to fix a few things of course, mostly in the area of planner and executor handling of row locks. As side effects of this, allow foreign tables to have NOT VALID CHECK constraints (and hence to accept ALTER ... VALIDATE CONSTRAINT), and to accept ALTER SET STORAGE and ALTER SET WITH/WITHOUT OIDS. Continuing to disallow these things would've required bizarre and inconsistent special cases in inheritance behavior. Since foreign tables don't enforce CHECK constraints anyway, a NOT VALID one is a complete no-op, but that doesn't mean we shouldn't allow it. And it's possible that some FDWs might have use for SET STORAGE or SET WITH OIDS, though doubtless they will be no-ops for most. An additional change in support of this is that when a ModifyTable node has multiple target tables, they will all now be explicitly identified in EXPLAIN output, for example: Update on pt1 (cost=0.00..321.05 rows=3541 width=46) Update on pt1 Foreign Update on ft1 Foreign Update on ft2 Update on child3 -> Seq Scan on pt1 (cost=0.00..0.00 rows=1 width=46) -> Foreign Scan on ft1 (cost=100.00..148.03 rows=1170 width=46) -> Foreign Scan on ft2 (cost=100.00..148.03 rows=1170 width=46) -> Seq Scan on child3 (cost=0.00..25.00 rows=1200 width=46) This was done mainly to provide an unambiguous place to attach "Remote SQL" fields, but it is useful for inherited updates even when no foreign tables are involved. Shigeru Hanada and Etsuro Fujita, reviewed by Ashutosh Bapat and Kyotaro Horiguchi, some additional hacking by me
2015-03-22 18:53:11 +01:00
*
* Here we show the nominal target (ie, the relation that was named in the
* original query). If the actual target(s) is/are different, we'll show them
* in show_modifytable_info().
*/
static void
ExplainModifyTarget(ModifyTable *plan, ExplainState *es)
{
ExplainTargetRel((Plan *) plan, plan->nominalRelation, es);
}
/*
* Show the target relation of a scan or modify node
*/
static void
ExplainTargetRel(Plan *plan, Index rti, ExplainState *es)
{
char *objectname = NULL;
char *namespace = NULL;
const char *objecttag = NULL;
RangeTblEntry *rte;
Improve ruleutils.c's heuristics for dealing with rangetable aliases. The previous scheme had bugs in some corner cases involving tables that had been renamed since a view was made. This could result in dumped views that failed to reload or reloaded incorrectly, as seen in bug #7553 from Lloyd Albin, as well as in some pgsql-hackers discussion back in January. Also, its behavior for printing EXPLAIN plans was sometimes confusing because of willingness to use the same alias for multiple RTEs (it was Ashutosh Bapat's complaint about that aspect that started the January thread). To fix, ensure that each RTE in the query has a unique unqualified alias, by modifying the alias if necessary (we add "_" and digits as needed to create a non-conflicting name). Then we can just print its variables with that alias, avoiding the confusing and bug-prone scheme of sometimes schema-qualifying variable names. In EXPLAIN, it proves to be expedient to take the further step of only assigning such aliases to RTEs that are actually referenced in the query, since the planner has a habit of generating extra RTEs with the same alias in situations such as inheritance-tree expansion. Although this fixes a bug of very long standing, I'm hesitant to back-patch such a noticeable behavioral change. My experiments while creating a regression test convinced me that actually incorrect output (as opposed to confusing output) occurs only in very narrow cases, which is backed up by the lack of previous complaints from the field. So we may be better off living with it in released branches; and in any case it'd be smart to let this ripen awhile in HEAD before we consider back-patching it.
2012-09-22 01:03:10 +02:00
char *refname;
rte = rt_fetch(rti, es->rtable);
Improve ruleutils.c's heuristics for dealing with rangetable aliases. The previous scheme had bugs in some corner cases involving tables that had been renamed since a view was made. This could result in dumped views that failed to reload or reloaded incorrectly, as seen in bug #7553 from Lloyd Albin, as well as in some pgsql-hackers discussion back in January. Also, its behavior for printing EXPLAIN plans was sometimes confusing because of willingness to use the same alias for multiple RTEs (it was Ashutosh Bapat's complaint about that aspect that started the January thread). To fix, ensure that each RTE in the query has a unique unqualified alias, by modifying the alias if necessary (we add "_" and digits as needed to create a non-conflicting name). Then we can just print its variables with that alias, avoiding the confusing and bug-prone scheme of sometimes schema-qualifying variable names. In EXPLAIN, it proves to be expedient to take the further step of only assigning such aliases to RTEs that are actually referenced in the query, since the planner has a habit of generating extra RTEs with the same alias in situations such as inheritance-tree expansion. Although this fixes a bug of very long standing, I'm hesitant to back-patch such a noticeable behavioral change. My experiments while creating a regression test convinced me that actually incorrect output (as opposed to confusing output) occurs only in very narrow cases, which is backed up by the lack of previous complaints from the field. So we may be better off living with it in released branches; and in any case it'd be smart to let this ripen awhile in HEAD before we consider back-patching it.
2012-09-22 01:03:10 +02:00
refname = (char *) list_nth(es->rtable_names, rti - 1);
if (refname == NULL)
refname = rte->eref->aliasname;
switch (nodeTag(plan))
{
case T_SeqScan:
Redesign tablesample method API, and do extensive code review. The original implementation of TABLESAMPLE modeled the tablesample method API on index access methods, which wasn't a good choice because, without specialized DDL commands, there's no way to build an extension that can implement a TSM. (Raw inserts into system catalogs are not an acceptable thing to do, because we can't undo them during DROP EXTENSION, nor will pg_upgrade behave sanely.) Instead adopt an API more like procedural language handlers or foreign data wrappers, wherein the only SQL-level support object needed is a single handler function identified by having a special return type. This lets us get rid of the supporting catalog altogether, so that no custom DDL support is needed for the feature. Adjust the API so that it can support non-constant tablesample arguments (the original coding assumed we could evaluate the argument expressions at ExecInitSampleScan time, which is undesirable even if it weren't outright unsafe), and discourage sampling methods from looking at invisible tuples. Make sure that the BERNOULLI and SYSTEM methods are genuinely repeatable within and across queries, as required by the SQL standard, and deal more honestly with methods that can't support that requirement. Make a full code-review pass over the tablesample additions, and fix assorted bugs, omissions, infelicities, and cosmetic issues (such as failure to put the added code stanzas in a consistent ordering). Improve EXPLAIN's output of tablesample plans, too. Back-patch to 9.5 so that we don't have to support the original API in production.
2015-07-25 20:39:00 +02:00
case T_SampleScan:
case T_IndexScan:
case T_IndexOnlyScan:
case T_BitmapHeapScan:
case T_TidScan:
case T_ForeignScan:
case T_CustomScan:
case T_ModifyTable:
/* Assert it's on a real relation */
Assert(rte->rtekind == RTE_RELATION);
objectname = get_rel_name(rte->relid);
if (es->verbose)
namespace = get_namespace_name(get_rel_namespace(rte->relid));
objecttag = "Relation Name";
break;
case T_FunctionScan:
{
FunctionScan *fscan = (FunctionScan *) plan;
/* Assert it's on a RangeFunction */
Assert(rte->rtekind == RTE_FUNCTION);
/*
* If the expression is still a function call of a single
* function, we can get the real name of the function.
* Otherwise, punt. (Even if it was a single function call
* originally, the optimizer could have simplified it away.)
*/
if (list_length(fscan->functions) == 1)
{
RangeTblFunction *rtfunc = (RangeTblFunction *) linitial(fscan->functions);
if (IsA(rtfunc->funcexpr, FuncExpr))
{
FuncExpr *funcexpr = (FuncExpr *) rtfunc->funcexpr;
Oid funcid = funcexpr->funcid;
objectname = get_func_name(funcid);
if (es->verbose)
namespace =
get_namespace_name(get_func_namespace(funcid));
}
}
objecttag = "Function Name";
}
break;
case T_TableFuncScan:
Assert(rte->rtekind == RTE_TABLEFUNC);
objectname = "xmltable";
objecttag = "Table Function Name";
break;
case T_ValuesScan:
Assert(rte->rtekind == RTE_VALUES);
break;
case T_CteScan:
/* Assert it's on a non-self-reference CTE */
Assert(rte->rtekind == RTE_CTE);
Assert(!rte->self_reference);
objectname = rte->ctename;
objecttag = "CTE Name";
break;
case T_NamedTuplestoreScan:
Assert(rte->rtekind == RTE_NAMEDTUPLESTORE);
objectname = rte->enrname;
objecttag = "Tuplestore Name";
break;
case T_WorkTableScan:
/* Assert it's on a self-reference CTE */
Assert(rte->rtekind == RTE_CTE);
Assert(rte->self_reference);
objectname = rte->ctename;
objecttag = "CTE Name";
break;
default:
break;
}
if (es->format == EXPLAIN_FORMAT_TEXT)
{
appendStringInfoString(es->str, " on");
if (namespace != NULL)
appendStringInfo(es->str, " %s.%s", quote_identifier(namespace),
quote_identifier(objectname));
else if (objectname != NULL)
appendStringInfo(es->str, " %s", quote_identifier(objectname));
if (objectname == NULL || strcmp(refname, objectname) != 0)
Improve ruleutils.c's heuristics for dealing with rangetable aliases. The previous scheme had bugs in some corner cases involving tables that had been renamed since a view was made. This could result in dumped views that failed to reload or reloaded incorrectly, as seen in bug #7553 from Lloyd Albin, as well as in some pgsql-hackers discussion back in January. Also, its behavior for printing EXPLAIN plans was sometimes confusing because of willingness to use the same alias for multiple RTEs (it was Ashutosh Bapat's complaint about that aspect that started the January thread). To fix, ensure that each RTE in the query has a unique unqualified alias, by modifying the alias if necessary (we add "_" and digits as needed to create a non-conflicting name). Then we can just print its variables with that alias, avoiding the confusing and bug-prone scheme of sometimes schema-qualifying variable names. In EXPLAIN, it proves to be expedient to take the further step of only assigning such aliases to RTEs that are actually referenced in the query, since the planner has a habit of generating extra RTEs with the same alias in situations such as inheritance-tree expansion. Although this fixes a bug of very long standing, I'm hesitant to back-patch such a noticeable behavioral change. My experiments while creating a regression test convinced me that actually incorrect output (as opposed to confusing output) occurs only in very narrow cases, which is backed up by the lack of previous complaints from the field. So we may be better off living with it in released branches; and in any case it'd be smart to let this ripen awhile in HEAD before we consider back-patching it.
2012-09-22 01:03:10 +02:00
appendStringInfo(es->str, " %s", quote_identifier(refname));
}
else
{
if (objecttag != NULL && objectname != NULL)
ExplainPropertyText(objecttag, objectname, es);
if (namespace != NULL)
ExplainPropertyText("Schema", namespace, es);
ExplainPropertyText("Alias", refname, es);
}
}
/*
* Show extra information for a ModifyTable node
Allow foreign tables to participate in inheritance. Foreign tables can now be inheritance children, or parents. Much of the system was already ready for this, but we had to fix a few things of course, mostly in the area of planner and executor handling of row locks. As side effects of this, allow foreign tables to have NOT VALID CHECK constraints (and hence to accept ALTER ... VALIDATE CONSTRAINT), and to accept ALTER SET STORAGE and ALTER SET WITH/WITHOUT OIDS. Continuing to disallow these things would've required bizarre and inconsistent special cases in inheritance behavior. Since foreign tables don't enforce CHECK constraints anyway, a NOT VALID one is a complete no-op, but that doesn't mean we shouldn't allow it. And it's possible that some FDWs might have use for SET STORAGE or SET WITH OIDS, though doubtless they will be no-ops for most. An additional change in support of this is that when a ModifyTable node has multiple target tables, they will all now be explicitly identified in EXPLAIN output, for example: Update on pt1 (cost=0.00..321.05 rows=3541 width=46) Update on pt1 Foreign Update on ft1 Foreign Update on ft2 Update on child3 -> Seq Scan on pt1 (cost=0.00..0.00 rows=1 width=46) -> Foreign Scan on ft1 (cost=100.00..148.03 rows=1170 width=46) -> Foreign Scan on ft2 (cost=100.00..148.03 rows=1170 width=46) -> Seq Scan on child3 (cost=0.00..25.00 rows=1200 width=46) This was done mainly to provide an unambiguous place to attach "Remote SQL" fields, but it is useful for inherited updates even when no foreign tables are involved. Shigeru Hanada and Etsuro Fujita, reviewed by Ashutosh Bapat and Kyotaro Horiguchi, some additional hacking by me
2015-03-22 18:53:11 +01:00
*
Add support for INSERT ... ON CONFLICT DO NOTHING/UPDATE. The newly added ON CONFLICT clause allows to specify an alternative to raising a unique or exclusion constraint violation error when inserting. ON CONFLICT refers to constraints that can either be specified using a inference clause (by specifying the columns of a unique constraint) or by naming a unique or exclusion constraint. DO NOTHING avoids the constraint violation, without touching the pre-existing row. DO UPDATE SET ... [WHERE ...] updates the pre-existing tuple, and has access to both the tuple proposed for insertion and the existing tuple; the optional WHERE clause can be used to prevent an update from being executed. The UPDATE SET and WHERE clauses have access to the tuple proposed for insertion using the "magic" EXCLUDED alias, and to the pre-existing tuple using the table name or its alias. This feature is often referred to as upsert. This is implemented using a new infrastructure called "speculative insertion". It is an optimistic variant of regular insertion that first does a pre-check for existing tuples and then attempts an insert. If a violating tuple was inserted concurrently, the speculatively inserted tuple is deleted and a new attempt is made. If the pre-check finds a matching tuple the alternative DO NOTHING or DO UPDATE action is taken. If the insertion succeeds without detecting a conflict, the tuple is deemed inserted. To handle the possible ambiguity between the excluded alias and a table named excluded, and for convenience with long relation names, INSERT INTO now can alias its target table. Bumps catversion as stored rules change. Author: Peter Geoghegan, with significant contributions from Heikki Linnakangas and Andres Freund. Testing infrastructure by Jeff Janes. Reviewed-By: Heikki Linnakangas, Andres Freund, Robert Haas, Simon Riggs, Dean Rasheed, Stephen Frost and many others.
2015-05-08 05:31:36 +02:00
* We have three objectives here. First, if there's more than one target
* table or it's different from the nominal target, identify the actual
* target(s). Second, give FDWs a chance to display extra info about foreign
* targets. Third, show information about ON CONFLICT.
*/
static void
Add support for INSERT ... ON CONFLICT DO NOTHING/UPDATE. The newly added ON CONFLICT clause allows to specify an alternative to raising a unique or exclusion constraint violation error when inserting. ON CONFLICT refers to constraints that can either be specified using a inference clause (by specifying the columns of a unique constraint) or by naming a unique or exclusion constraint. DO NOTHING avoids the constraint violation, without touching the pre-existing row. DO UPDATE SET ... [WHERE ...] updates the pre-existing tuple, and has access to both the tuple proposed for insertion and the existing tuple; the optional WHERE clause can be used to prevent an update from being executed. The UPDATE SET and WHERE clauses have access to the tuple proposed for insertion using the "magic" EXCLUDED alias, and to the pre-existing tuple using the table name or its alias. This feature is often referred to as upsert. This is implemented using a new infrastructure called "speculative insertion". It is an optimistic variant of regular insertion that first does a pre-check for existing tuples and then attempts an insert. If a violating tuple was inserted concurrently, the speculatively inserted tuple is deleted and a new attempt is made. If the pre-check finds a matching tuple the alternative DO NOTHING or DO UPDATE action is taken. If the insertion succeeds without detecting a conflict, the tuple is deemed inserted. To handle the possible ambiguity between the excluded alias and a table named excluded, and for convenience with long relation names, INSERT INTO now can alias its target table. Bumps catversion as stored rules change. Author: Peter Geoghegan, with significant contributions from Heikki Linnakangas and Andres Freund. Testing infrastructure by Jeff Janes. Reviewed-By: Heikki Linnakangas, Andres Freund, Robert Haas, Simon Riggs, Dean Rasheed, Stephen Frost and many others.
2015-05-08 05:31:36 +02:00
show_modifytable_info(ModifyTableState *mtstate, List *ancestors,
ExplainState *es)
{
Allow foreign tables to participate in inheritance. Foreign tables can now be inheritance children, or parents. Much of the system was already ready for this, but we had to fix a few things of course, mostly in the area of planner and executor handling of row locks. As side effects of this, allow foreign tables to have NOT VALID CHECK constraints (and hence to accept ALTER ... VALIDATE CONSTRAINT), and to accept ALTER SET STORAGE and ALTER SET WITH/WITHOUT OIDS. Continuing to disallow these things would've required bizarre and inconsistent special cases in inheritance behavior. Since foreign tables don't enforce CHECK constraints anyway, a NOT VALID one is a complete no-op, but that doesn't mean we shouldn't allow it. And it's possible that some FDWs might have use for SET STORAGE or SET WITH OIDS, though doubtless they will be no-ops for most. An additional change in support of this is that when a ModifyTable node has multiple target tables, they will all now be explicitly identified in EXPLAIN output, for example: Update on pt1 (cost=0.00..321.05 rows=3541 width=46) Update on pt1 Foreign Update on ft1 Foreign Update on ft2 Update on child3 -> Seq Scan on pt1 (cost=0.00..0.00 rows=1 width=46) -> Foreign Scan on ft1 (cost=100.00..148.03 rows=1170 width=46) -> Foreign Scan on ft2 (cost=100.00..148.03 rows=1170 width=46) -> Seq Scan on child3 (cost=0.00..25.00 rows=1200 width=46) This was done mainly to provide an unambiguous place to attach "Remote SQL" fields, but it is useful for inherited updates even when no foreign tables are involved. Shigeru Hanada and Etsuro Fujita, reviewed by Ashutosh Bapat and Kyotaro Horiguchi, some additional hacking by me
2015-03-22 18:53:11 +01:00
ModifyTable *node = (ModifyTable *) mtstate->ps.plan;
const char *operation;
const char *foperation;
bool labeltargets;
int j;
Add support for INSERT ... ON CONFLICT DO NOTHING/UPDATE. The newly added ON CONFLICT clause allows to specify an alternative to raising a unique or exclusion constraint violation error when inserting. ON CONFLICT refers to constraints that can either be specified using a inference clause (by specifying the columns of a unique constraint) or by naming a unique or exclusion constraint. DO NOTHING avoids the constraint violation, without touching the pre-existing row. DO UPDATE SET ... [WHERE ...] updates the pre-existing tuple, and has access to both the tuple proposed for insertion and the existing tuple; the optional WHERE clause can be used to prevent an update from being executed. The UPDATE SET and WHERE clauses have access to the tuple proposed for insertion using the "magic" EXCLUDED alias, and to the pre-existing tuple using the table name or its alias. This feature is often referred to as upsert. This is implemented using a new infrastructure called "speculative insertion". It is an optimistic variant of regular insertion that first does a pre-check for existing tuples and then attempts an insert. If a violating tuple was inserted concurrently, the speculatively inserted tuple is deleted and a new attempt is made. If the pre-check finds a matching tuple the alternative DO NOTHING or DO UPDATE action is taken. If the insertion succeeds without detecting a conflict, the tuple is deemed inserted. To handle the possible ambiguity between the excluded alias and a table named excluded, and for convenience with long relation names, INSERT INTO now can alias its target table. Bumps catversion as stored rules change. Author: Peter Geoghegan, with significant contributions from Heikki Linnakangas and Andres Freund. Testing infrastructure by Jeff Janes. Reviewed-By: Heikki Linnakangas, Andres Freund, Robert Haas, Simon Riggs, Dean Rasheed, Stephen Frost and many others.
2015-05-08 05:31:36 +02:00
List *idxNames = NIL;
ListCell *lst;
Allow foreign tables to participate in inheritance. Foreign tables can now be inheritance children, or parents. Much of the system was already ready for this, but we had to fix a few things of course, mostly in the area of planner and executor handling of row locks. As side effects of this, allow foreign tables to have NOT VALID CHECK constraints (and hence to accept ALTER ... VALIDATE CONSTRAINT), and to accept ALTER SET STORAGE and ALTER SET WITH/WITHOUT OIDS. Continuing to disallow these things would've required bizarre and inconsistent special cases in inheritance behavior. Since foreign tables don't enforce CHECK constraints anyway, a NOT VALID one is a complete no-op, but that doesn't mean we shouldn't allow it. And it's possible that some FDWs might have use for SET STORAGE or SET WITH OIDS, though doubtless they will be no-ops for most. An additional change in support of this is that when a ModifyTable node has multiple target tables, they will all now be explicitly identified in EXPLAIN output, for example: Update on pt1 (cost=0.00..321.05 rows=3541 width=46) Update on pt1 Foreign Update on ft1 Foreign Update on ft2 Update on child3 -> Seq Scan on pt1 (cost=0.00..0.00 rows=1 width=46) -> Foreign Scan on ft1 (cost=100.00..148.03 rows=1170 width=46) -> Foreign Scan on ft2 (cost=100.00..148.03 rows=1170 width=46) -> Seq Scan on child3 (cost=0.00..25.00 rows=1200 width=46) This was done mainly to provide an unambiguous place to attach "Remote SQL" fields, but it is useful for inherited updates even when no foreign tables are involved. Shigeru Hanada and Etsuro Fujita, reviewed by Ashutosh Bapat and Kyotaro Horiguchi, some additional hacking by me
2015-03-22 18:53:11 +01:00
switch (node->operation)
{
Allow foreign tables to participate in inheritance. Foreign tables can now be inheritance children, or parents. Much of the system was already ready for this, but we had to fix a few things of course, mostly in the area of planner and executor handling of row locks. As side effects of this, allow foreign tables to have NOT VALID CHECK constraints (and hence to accept ALTER ... VALIDATE CONSTRAINT), and to accept ALTER SET STORAGE and ALTER SET WITH/WITHOUT OIDS. Continuing to disallow these things would've required bizarre and inconsistent special cases in inheritance behavior. Since foreign tables don't enforce CHECK constraints anyway, a NOT VALID one is a complete no-op, but that doesn't mean we shouldn't allow it. And it's possible that some FDWs might have use for SET STORAGE or SET WITH OIDS, though doubtless they will be no-ops for most. An additional change in support of this is that when a ModifyTable node has multiple target tables, they will all now be explicitly identified in EXPLAIN output, for example: Update on pt1 (cost=0.00..321.05 rows=3541 width=46) Update on pt1 Foreign Update on ft1 Foreign Update on ft2 Update on child3 -> Seq Scan on pt1 (cost=0.00..0.00 rows=1 width=46) -> Foreign Scan on ft1 (cost=100.00..148.03 rows=1170 width=46) -> Foreign Scan on ft2 (cost=100.00..148.03 rows=1170 width=46) -> Seq Scan on child3 (cost=0.00..25.00 rows=1200 width=46) This was done mainly to provide an unambiguous place to attach "Remote SQL" fields, but it is useful for inherited updates even when no foreign tables are involved. Shigeru Hanada and Etsuro Fujita, reviewed by Ashutosh Bapat and Kyotaro Horiguchi, some additional hacking by me
2015-03-22 18:53:11 +01:00
case CMD_INSERT:
operation = "Insert";
foperation = "Foreign Insert";
break;
case CMD_UPDATE:
operation = "Update";
foperation = "Foreign Update";
break;
case CMD_DELETE:
operation = "Delete";
foperation = "Foreign Delete";
break;
default:
operation = "???";
foperation = "Foreign ???";
break;
}
Allow foreign tables to participate in inheritance. Foreign tables can now be inheritance children, or parents. Much of the system was already ready for this, but we had to fix a few things of course, mostly in the area of planner and executor handling of row locks. As side effects of this, allow foreign tables to have NOT VALID CHECK constraints (and hence to accept ALTER ... VALIDATE CONSTRAINT), and to accept ALTER SET STORAGE and ALTER SET WITH/WITHOUT OIDS. Continuing to disallow these things would've required bizarre and inconsistent special cases in inheritance behavior. Since foreign tables don't enforce CHECK constraints anyway, a NOT VALID one is a complete no-op, but that doesn't mean we shouldn't allow it. And it's possible that some FDWs might have use for SET STORAGE or SET WITH OIDS, though doubtless they will be no-ops for most. An additional change in support of this is that when a ModifyTable node has multiple target tables, they will all now be explicitly identified in EXPLAIN output, for example: Update on pt1 (cost=0.00..321.05 rows=3541 width=46) Update on pt1 Foreign Update on ft1 Foreign Update on ft2 Update on child3 -> Seq Scan on pt1 (cost=0.00..0.00 rows=1 width=46) -> Foreign Scan on ft1 (cost=100.00..148.03 rows=1170 width=46) -> Foreign Scan on ft2 (cost=100.00..148.03 rows=1170 width=46) -> Seq Scan on child3 (cost=0.00..25.00 rows=1200 width=46) This was done mainly to provide an unambiguous place to attach "Remote SQL" fields, but it is useful for inherited updates even when no foreign tables are involved. Shigeru Hanada and Etsuro Fujita, reviewed by Ashutosh Bapat and Kyotaro Horiguchi, some additional hacking by me
2015-03-22 18:53:11 +01:00
/* Should we explicitly label target relations? */
labeltargets = (mtstate->mt_nplans > 1 ||
(mtstate->mt_nplans == 1 &&
mtstate->resultRelInfo->ri_RangeTableIndex != node->nominalRelation));
Allow foreign tables to participate in inheritance. Foreign tables can now be inheritance children, or parents. Much of the system was already ready for this, but we had to fix a few things of course, mostly in the area of planner and executor handling of row locks. As side effects of this, allow foreign tables to have NOT VALID CHECK constraints (and hence to accept ALTER ... VALIDATE CONSTRAINT), and to accept ALTER SET STORAGE and ALTER SET WITH/WITHOUT OIDS. Continuing to disallow these things would've required bizarre and inconsistent special cases in inheritance behavior. Since foreign tables don't enforce CHECK constraints anyway, a NOT VALID one is a complete no-op, but that doesn't mean we shouldn't allow it. And it's possible that some FDWs might have use for SET STORAGE or SET WITH OIDS, though doubtless they will be no-ops for most. An additional change in support of this is that when a ModifyTable node has multiple target tables, they will all now be explicitly identified in EXPLAIN output, for example: Update on pt1 (cost=0.00..321.05 rows=3541 width=46) Update on pt1 Foreign Update on ft1 Foreign Update on ft2 Update on child3 -> Seq Scan on pt1 (cost=0.00..0.00 rows=1 width=46) -> Foreign Scan on ft1 (cost=100.00..148.03 rows=1170 width=46) -> Foreign Scan on ft2 (cost=100.00..148.03 rows=1170 width=46) -> Seq Scan on child3 (cost=0.00..25.00 rows=1200 width=46) This was done mainly to provide an unambiguous place to attach "Remote SQL" fields, but it is useful for inherited updates even when no foreign tables are involved. Shigeru Hanada and Etsuro Fujita, reviewed by Ashutosh Bapat and Kyotaro Horiguchi, some additional hacking by me
2015-03-22 18:53:11 +01:00
if (labeltargets)
ExplainOpenGroup("Target Tables", "Target Tables", false, es);
for (j = 0; j < mtstate->mt_nplans; j++)
{
ResultRelInfo *resultRelInfo = mtstate->resultRelInfo + j;
FdwRoutine *fdwroutine = resultRelInfo->ri_FdwRoutine;
if (labeltargets)
{
/* Open a group for this target */
ExplainOpenGroup("Target Table", NULL, true, es);
/*
* In text mode, decorate each target with operation type, so that
* ExplainTargetRel's output of " on foo" will read nicely.
*/
if (es->format == EXPLAIN_FORMAT_TEXT)
{
appendStringInfoSpaces(es->str, es->indent * 2);
appendStringInfoString(es->str,
fdwroutine ? foperation : operation);
}
/* Identify target */
ExplainTargetRel((Plan *) node,
resultRelInfo->ri_RangeTableIndex,
es);
if (es->format == EXPLAIN_FORMAT_TEXT)
{
appendStringInfoChar(es->str, '\n');
es->indent++;
}
}
/* Give FDW a chance if needed */
if (!resultRelInfo->ri_usesFdwDirectModify &&
fdwroutine != NULL &&
fdwroutine->ExplainForeignModify != NULL)
Allow foreign tables to participate in inheritance. Foreign tables can now be inheritance children, or parents. Much of the system was already ready for this, but we had to fix a few things of course, mostly in the area of planner and executor handling of row locks. As side effects of this, allow foreign tables to have NOT VALID CHECK constraints (and hence to accept ALTER ... VALIDATE CONSTRAINT), and to accept ALTER SET STORAGE and ALTER SET WITH/WITHOUT OIDS. Continuing to disallow these things would've required bizarre and inconsistent special cases in inheritance behavior. Since foreign tables don't enforce CHECK constraints anyway, a NOT VALID one is a complete no-op, but that doesn't mean we shouldn't allow it. And it's possible that some FDWs might have use for SET STORAGE or SET WITH OIDS, though doubtless they will be no-ops for most. An additional change in support of this is that when a ModifyTable node has multiple target tables, they will all now be explicitly identified in EXPLAIN output, for example: Update on pt1 (cost=0.00..321.05 rows=3541 width=46) Update on pt1 Foreign Update on ft1 Foreign Update on ft2 Update on child3 -> Seq Scan on pt1 (cost=0.00..0.00 rows=1 width=46) -> Foreign Scan on ft1 (cost=100.00..148.03 rows=1170 width=46) -> Foreign Scan on ft2 (cost=100.00..148.03 rows=1170 width=46) -> Seq Scan on child3 (cost=0.00..25.00 rows=1200 width=46) This was done mainly to provide an unambiguous place to attach "Remote SQL" fields, but it is useful for inherited updates even when no foreign tables are involved. Shigeru Hanada and Etsuro Fujita, reviewed by Ashutosh Bapat and Kyotaro Horiguchi, some additional hacking by me
2015-03-22 18:53:11 +01:00
{
List *fdw_private = (List *) list_nth(node->fdwPrivLists, j);
fdwroutine->ExplainForeignModify(mtstate,
resultRelInfo,
fdw_private,
j,
es);
}
if (labeltargets)
{
/* Undo the indentation we added in text format */
if (es->format == EXPLAIN_FORMAT_TEXT)
es->indent--;
/* Close the group */
ExplainCloseGroup("Target Table", NULL, true, es);
}
}
Add support for INSERT ... ON CONFLICT DO NOTHING/UPDATE. The newly added ON CONFLICT clause allows to specify an alternative to raising a unique or exclusion constraint violation error when inserting. ON CONFLICT refers to constraints that can either be specified using a inference clause (by specifying the columns of a unique constraint) or by naming a unique or exclusion constraint. DO NOTHING avoids the constraint violation, without touching the pre-existing row. DO UPDATE SET ... [WHERE ...] updates the pre-existing tuple, and has access to both the tuple proposed for insertion and the existing tuple; the optional WHERE clause can be used to prevent an update from being executed. The UPDATE SET and WHERE clauses have access to the tuple proposed for insertion using the "magic" EXCLUDED alias, and to the pre-existing tuple using the table name or its alias. This feature is often referred to as upsert. This is implemented using a new infrastructure called "speculative insertion". It is an optimistic variant of regular insertion that first does a pre-check for existing tuples and then attempts an insert. If a violating tuple was inserted concurrently, the speculatively inserted tuple is deleted and a new attempt is made. If the pre-check finds a matching tuple the alternative DO NOTHING or DO UPDATE action is taken. If the insertion succeeds without detecting a conflict, the tuple is deemed inserted. To handle the possible ambiguity between the excluded alias and a table named excluded, and for convenience with long relation names, INSERT INTO now can alias its target table. Bumps catversion as stored rules change. Author: Peter Geoghegan, with significant contributions from Heikki Linnakangas and Andres Freund. Testing infrastructure by Jeff Janes. Reviewed-By: Heikki Linnakangas, Andres Freund, Robert Haas, Simon Riggs, Dean Rasheed, Stephen Frost and many others.
2015-05-08 05:31:36 +02:00
/* Gather names of ON CONFLICT arbiter indexes */
foreach(lst, node->arbiterIndexes)
{
char *indexname = get_rel_name(lfirst_oid(lst));
idxNames = lappend(idxNames, indexname);
}
if (node->onConflictAction != ONCONFLICT_NONE)
{
ExplainProperty("Conflict Resolution",
node->onConflictAction == ONCONFLICT_NOTHING ?
2015-05-24 03:35:49 +02:00
"NOTHING" : "UPDATE",
Add support for INSERT ... ON CONFLICT DO NOTHING/UPDATE. The newly added ON CONFLICT clause allows to specify an alternative to raising a unique or exclusion constraint violation error when inserting. ON CONFLICT refers to constraints that can either be specified using a inference clause (by specifying the columns of a unique constraint) or by naming a unique or exclusion constraint. DO NOTHING avoids the constraint violation, without touching the pre-existing row. DO UPDATE SET ... [WHERE ...] updates the pre-existing tuple, and has access to both the tuple proposed for insertion and the existing tuple; the optional WHERE clause can be used to prevent an update from being executed. The UPDATE SET and WHERE clauses have access to the tuple proposed for insertion using the "magic" EXCLUDED alias, and to the pre-existing tuple using the table name or its alias. This feature is often referred to as upsert. This is implemented using a new infrastructure called "speculative insertion". It is an optimistic variant of regular insertion that first does a pre-check for existing tuples and then attempts an insert. If a violating tuple was inserted concurrently, the speculatively inserted tuple is deleted and a new attempt is made. If the pre-check finds a matching tuple the alternative DO NOTHING or DO UPDATE action is taken. If the insertion succeeds without detecting a conflict, the tuple is deemed inserted. To handle the possible ambiguity between the excluded alias and a table named excluded, and for convenience with long relation names, INSERT INTO now can alias its target table. Bumps catversion as stored rules change. Author: Peter Geoghegan, with significant contributions from Heikki Linnakangas and Andres Freund. Testing infrastructure by Jeff Janes. Reviewed-By: Heikki Linnakangas, Andres Freund, Robert Haas, Simon Riggs, Dean Rasheed, Stephen Frost and many others.
2015-05-08 05:31:36 +02:00
false, es);
/*
* Don't display arbiter indexes at all when DO NOTHING variant
* implicitly ignores all conflicts
*/
if (idxNames)
ExplainPropertyList("Conflict Arbiter Indexes", idxNames, es);
/* ON CONFLICT DO UPDATE WHERE qual is specially displayed */
if (node->onConflictWhere)
{
show_upper_qual((List *) node->onConflictWhere, "Conflict Filter",
&mtstate->ps, ancestors, es);
show_instrumentation_count("Rows Removed by Conflict Filter", 1, &mtstate->ps, es);
}
/* EXPLAIN ANALYZE display of actual outcome for each tuple proposed */
if (es->analyze && mtstate->ps.instrument)
{
2015-05-24 03:35:49 +02:00
double total;
double insert_path;
double other_path;
Add support for INSERT ... ON CONFLICT DO NOTHING/UPDATE. The newly added ON CONFLICT clause allows to specify an alternative to raising a unique or exclusion constraint violation error when inserting. ON CONFLICT refers to constraints that can either be specified using a inference clause (by specifying the columns of a unique constraint) or by naming a unique or exclusion constraint. DO NOTHING avoids the constraint violation, without touching the pre-existing row. DO UPDATE SET ... [WHERE ...] updates the pre-existing tuple, and has access to both the tuple proposed for insertion and the existing tuple; the optional WHERE clause can be used to prevent an update from being executed. The UPDATE SET and WHERE clauses have access to the tuple proposed for insertion using the "magic" EXCLUDED alias, and to the pre-existing tuple using the table name or its alias. This feature is often referred to as upsert. This is implemented using a new infrastructure called "speculative insertion". It is an optimistic variant of regular insertion that first does a pre-check for existing tuples and then attempts an insert. If a violating tuple was inserted concurrently, the speculatively inserted tuple is deleted and a new attempt is made. If the pre-check finds a matching tuple the alternative DO NOTHING or DO UPDATE action is taken. If the insertion succeeds without detecting a conflict, the tuple is deemed inserted. To handle the possible ambiguity between the excluded alias and a table named excluded, and for convenience with long relation names, INSERT INTO now can alias its target table. Bumps catversion as stored rules change. Author: Peter Geoghegan, with significant contributions from Heikki Linnakangas and Andres Freund. Testing infrastructure by Jeff Janes. Reviewed-By: Heikki Linnakangas, Andres Freund, Robert Haas, Simon Riggs, Dean Rasheed, Stephen Frost and many others.
2015-05-08 05:31:36 +02:00
InstrEndLoop(mtstate->mt_plans[0]->instrument);
/* count the number of source rows */
total = mtstate->mt_plans[0]->instrument->ntuples;
other_path = mtstate->ps.instrument->nfiltered2;
insert_path = total - other_path;
ExplainPropertyFloat("Tuples Inserted", insert_path, 0, es);
ExplainPropertyFloat("Conflicting Tuples", other_path, 0, es);
}
}
Allow foreign tables to participate in inheritance. Foreign tables can now be inheritance children, or parents. Much of the system was already ready for this, but we had to fix a few things of course, mostly in the area of planner and executor handling of row locks. As side effects of this, allow foreign tables to have NOT VALID CHECK constraints (and hence to accept ALTER ... VALIDATE CONSTRAINT), and to accept ALTER SET STORAGE and ALTER SET WITH/WITHOUT OIDS. Continuing to disallow these things would've required bizarre and inconsistent special cases in inheritance behavior. Since foreign tables don't enforce CHECK constraints anyway, a NOT VALID one is a complete no-op, but that doesn't mean we shouldn't allow it. And it's possible that some FDWs might have use for SET STORAGE or SET WITH OIDS, though doubtless they will be no-ops for most. An additional change in support of this is that when a ModifyTable node has multiple target tables, they will all now be explicitly identified in EXPLAIN output, for example: Update on pt1 (cost=0.00..321.05 rows=3541 width=46) Update on pt1 Foreign Update on ft1 Foreign Update on ft2 Update on child3 -> Seq Scan on pt1 (cost=0.00..0.00 rows=1 width=46) -> Foreign Scan on ft1 (cost=100.00..148.03 rows=1170 width=46) -> Foreign Scan on ft2 (cost=100.00..148.03 rows=1170 width=46) -> Seq Scan on child3 (cost=0.00..25.00 rows=1200 width=46) This was done mainly to provide an unambiguous place to attach "Remote SQL" fields, but it is useful for inherited updates even when no foreign tables are involved. Shigeru Hanada and Etsuro Fujita, reviewed by Ashutosh Bapat and Kyotaro Horiguchi, some additional hacking by me
2015-03-22 18:53:11 +01:00
if (labeltargets)
ExplainCloseGroup("Target Tables", "Target Tables", false, es);
}
/*
* Explain the constituent plans of a ModifyTable, Append, MergeAppend,
* BitmapAnd, or BitmapOr node.
*
* The ancestors list should already contain the immediate parent of these
* plans.
*
* Note: we don't actually need to examine the Plan list members, but
* we need the list in order to determine the length of the PlanState array.
*/
static void
ExplainMemberNodes(List *plans, PlanState **planstates,
List *ancestors, ExplainState *es)
{
int nplans = list_length(plans);
int j;
for (j = 0; j < nplans; j++)
ExplainNode(planstates[j], ancestors,
"Member", NULL, es);
}
/*
* Explain a list of SubPlans (or initPlans, which also use SubPlan nodes).
*
* The ancestors list should already contain the immediate parent of these
* SubPlanStates.
*/
static void
ExplainSubPlans(List *plans, List *ancestors,
const char *relationship, ExplainState *es)
{
ListCell *lst;
foreach(lst, plans)
{
SubPlanState *sps = (SubPlanState *) lfirst(lst);
Faster expression evaluation and targetlist projection. This replaces the old, recursive tree-walk based evaluation, with non-recursive, opcode dispatch based, expression evaluation. Projection is now implemented as part of expression evaluation. This both leads to significant performance improvements, and makes future just-in-time compilation of expressions easier. The speed gains primarily come from: - non-recursive implementation reduces stack usage / overhead - simple sub-expressions are implemented with a single jump, without function calls - sharing some state between different sub-expressions - reduced amount of indirect/hard to predict memory accesses by laying out operation metadata sequentially; including the avoidance of nearly all of the previously used linked lists - more code has been moved to expression initialization, avoiding constant re-checks at evaluation time Future just-in-time compilation (JIT) has become easier, as demonstrated by released patches intended to be merged in a later release, for primarily two reasons: Firstly, due to a stricter split between expression initialization and evaluation, less code has to be handled by the JIT. Secondly, due to the non-recursive nature of the generated "instructions", less performance-critical code-paths can easily be shared between interpreted and compiled evaluation. The new framework allows for significant future optimizations. E.g.: - basic infrastructure for to later reduce the per executor-startup overhead of expression evaluation, by caching state in prepared statements. That'd be helpful in OLTPish scenarios where initialization overhead is measurable. - optimizing the generated "code". A number of proposals for potential work has already been made. - optimizing the interpreter. Similarly a number of proposals have been made here too. The move of logic into the expression initialization step leads to some backward-incompatible changes: - Function permission checks are now done during expression initialization, whereas previously they were done during execution. In edge cases this can lead to errors being raised that previously wouldn't have been, e.g. a NULL array being coerced to a different array type previously didn't perform checks. - The set of domain constraints to be checked, is now evaluated once during expression initialization, previously it was re-built every time a domain check was evaluated. For normal queries this doesn't change much, but e.g. for plpgsql functions, which caches ExprStates, the old set could stick around longer. The behavior around might still change. Author: Andres Freund, with significant changes by Tom Lane, changes by Heikki Linnakangas Reviewed-By: Tom Lane, Heikki Linnakangas Discussion: https://postgr.es/m/20161206034955.bh33paeralxbtluv@alap3.anarazel.de
2017-03-14 23:45:36 +01:00
SubPlan *sp = sps->subplan;
Print a given subplan only once in EXPLAIN. We have, for a very long time, allowed the same subplan (same member of the PlannedStmt.subplans list) to be referenced by more than one SubPlan node; this avoids problems for cases such as subplans within an IndexScan's indxqual and indxqualorig fields. However, EXPLAIN had not gotten the memo and would print each reference as though it were an independent identical subplan. To fix, track plan_ids of subplans we've printed and don't print the same plan_id twice. Per report from Pavel Stehule. BTW: the particular case of IndexScan didn't cause visible duplication in a plain EXPLAIN, only EXPLAIN ANALYZE, because in the former case we short-circuit executor startup before the indxqual field is processed by ExecInitExpr. That seems like it could easily lead to other EXPLAIN problems in future, but it's not clear how to avoid it without breaking the "EXPLAIN a plan using hypothetical indexes" use-case. For now I've left that issue alone. Although this is a longstanding bug, it's purely cosmetic (no great harm is done by the repeat printout) and we haven't had field complaints before. So I'm hesitant to back-patch it, especially since there is some small risk of ABI problems due to the need to add a new field to ExplainState. In passing, rearrange order of fields in ExplainState to be less random, and update some obsolete comments about when/where to initialize them. Report: <CAFj8pRAimq+NK-menjt+3J4-LFoodDD8Or6=Lc_stcFD+eD4DA@mail.gmail.com>
2016-07-12 00:14:29 +02:00
/*
* There can be multiple SubPlan nodes referencing the same physical
* subplan (same plan_id, which is its index in PlannedStmt.subplans).
* We should print a subplan only once, so track which ones we already
* printed. This state must be global across the plan tree, since the
* duplicate nodes could be in different plan nodes, eg both a bitmap
* indexscan's indexqual and its parent heapscan's recheck qual. (We
* do not worry too much about which plan node we show the subplan as
* attached to in such cases.)
*/
if (bms_is_member(sp->plan_id, es->printed_subplans))
continue;
es->printed_subplans = bms_add_member(es->printed_subplans,
sp->plan_id);
ExplainNode(sps->planstate, ancestors,
relationship, sp->plan_name, es);
}
}
/*
* Explain a list of children of a CustomScan.
*/
static void
ExplainCustomChildren(CustomScanState *css, List *ancestors, ExplainState *es)
{
ListCell *cell;
const char *label =
Redesign tablesample method API, and do extensive code review. The original implementation of TABLESAMPLE modeled the tablesample method API on index access methods, which wasn't a good choice because, without specialized DDL commands, there's no way to build an extension that can implement a TSM. (Raw inserts into system catalogs are not an acceptable thing to do, because we can't undo them during DROP EXTENSION, nor will pg_upgrade behave sanely.) Instead adopt an API more like procedural language handlers or foreign data wrappers, wherein the only SQL-level support object needed is a single handler function identified by having a special return type. This lets us get rid of the supporting catalog altogether, so that no custom DDL support is needed for the feature. Adjust the API so that it can support non-constant tablesample arguments (the original coding assumed we could evaluate the argument expressions at ExecInitSampleScan time, which is undesirable even if it weren't outright unsafe), and discourage sampling methods from looking at invisible tuples. Make sure that the BERNOULLI and SYSTEM methods are genuinely repeatable within and across queries, as required by the SQL standard, and deal more honestly with methods that can't support that requirement. Make a full code-review pass over the tablesample additions, and fix assorted bugs, omissions, infelicities, and cosmetic issues (such as failure to put the added code stanzas in a consistent ordering). Improve EXPLAIN's output of tablesample plans, too. Back-patch to 9.5 so that we don't have to support the original API in production.
2015-07-25 20:39:00 +02:00
(list_length(css->custom_ps) != 1 ? "children" : "child");
Redesign tablesample method API, and do extensive code review. The original implementation of TABLESAMPLE modeled the tablesample method API on index access methods, which wasn't a good choice because, without specialized DDL commands, there's no way to build an extension that can implement a TSM. (Raw inserts into system catalogs are not an acceptable thing to do, because we can't undo them during DROP EXTENSION, nor will pg_upgrade behave sanely.) Instead adopt an API more like procedural language handlers or foreign data wrappers, wherein the only SQL-level support object needed is a single handler function identified by having a special return type. This lets us get rid of the supporting catalog altogether, so that no custom DDL support is needed for the feature. Adjust the API so that it can support non-constant tablesample arguments (the original coding assumed we could evaluate the argument expressions at ExecInitSampleScan time, which is undesirable even if it weren't outright unsafe), and discourage sampling methods from looking at invisible tuples. Make sure that the BERNOULLI and SYSTEM methods are genuinely repeatable within and across queries, as required by the SQL standard, and deal more honestly with methods that can't support that requirement. Make a full code-review pass over the tablesample additions, and fix assorted bugs, omissions, infelicities, and cosmetic issues (such as failure to put the added code stanzas in a consistent ordering). Improve EXPLAIN's output of tablesample plans, too. Back-patch to 9.5 so that we don't have to support the original API in production.
2015-07-25 20:39:00 +02:00
foreach(cell, css->custom_ps)
ExplainNode((PlanState *) lfirst(cell), ancestors, label, NULL, es);
}
/*
* Explain a property, such as sort keys or targets, that takes the form of
* a list of unlabeled items. "data" is a list of C strings.
*/
void
ExplainPropertyList(const char *qlabel, List *data, ExplainState *es)
{
ListCell *lc;
bool first = true;
switch (es->format)
{
case EXPLAIN_FORMAT_TEXT:
appendStringInfoSpaces(es->str, es->indent * 2);
appendStringInfo(es->str, "%s: ", qlabel);
foreach(lc, data)
{
if (!first)
appendStringInfoString(es->str, ", ");
appendStringInfoString(es->str, (const char *) lfirst(lc));
first = false;
}
appendStringInfoChar(es->str, '\n');
break;
case EXPLAIN_FORMAT_XML:
ExplainXMLTag(qlabel, X_OPENING, es);
foreach(lc, data)
{
2010-02-26 03:01:40 +01:00
char *str;
appendStringInfoSpaces(es->str, es->indent * 2 + 2);
appendStringInfoString(es->str, "<Item>");
str = escape_xml((const char *) lfirst(lc));
appendStringInfoString(es->str, str);
pfree(str);
appendStringInfoString(es->str, "</Item>\n");
}
ExplainXMLTag(qlabel, X_CLOSING, es);
break;
case EXPLAIN_FORMAT_JSON:
ExplainJSONLineEnding(es);
appendStringInfoSpaces(es->str, es->indent * 2);
escape_json(es->str, qlabel);
appendStringInfoString(es->str, ": [");
foreach(lc, data)
{
if (!first)
appendStringInfoString(es->str, ", ");
escape_json(es->str, (const char *) lfirst(lc));
first = false;
}
appendStringInfoChar(es->str, ']');
break;
case EXPLAIN_FORMAT_YAML:
ExplainYAMLLineStarting(es);
appendStringInfo(es->str, "%s: ", qlabel);
foreach(lc, data)
{
appendStringInfoChar(es->str, '\n');
appendStringInfoSpaces(es->str, es->indent * 2 + 2);
appendStringInfoString(es->str, "- ");
escape_yaml(es->str, (const char *) lfirst(lc));
}
break;
}
}
Support GROUPING SETS, CUBE and ROLLUP. This SQL standard functionality allows to aggregate data by different GROUP BY clauses at once. Each grouping set returns rows with columns grouped by in other sets set to NULL. This could previously be achieved by doing each grouping as a separate query, conjoined by UNION ALLs. Besides being considerably more concise, grouping sets will in many cases be faster, requiring only one scan over the underlying data. The current implementation of grouping sets only supports using sorting for input. Individual sets that share a sort order are computed in one pass. If there are sets that don't share a sort order, additional sort & aggregation steps are performed. These additional passes are sourced by the previous sort step; thus avoiding repeated scans of the source data. The code is structured in a way that adding support for purely using hash aggregation or a mix of hashing and sorting is possible. Sorting was chosen to be supported first, as it is the most generic method of implementation. Instead of, as in an earlier versions of the patch, representing the chain of sort and aggregation steps as full blown planner and executor nodes, all but the first sort are performed inside the aggregation node itself. This avoids the need to do some unusual gymnastics to handle having to return aggregated and non-aggregated tuples from underlying nodes, as well as having to shut down underlying nodes early to limit memory usage. The optimizer still builds Sort/Agg node to describe each phase, but they're not part of the plan tree, but instead additional data for the aggregation node. They're a convenient and preexisting way to describe aggregation and sorting. The first (and possibly only) sort step is still performed as a separate execution step. That retains similarity with existing group by plans, makes rescans fairly simple, avoids very deep plans (leading to slow explains) and easily allows to avoid the sorting step if the underlying data is sorted by other means. A somewhat ugly side of this patch is having to deal with a grammar ambiguity between the new CUBE keyword and the cube extension/functions named cube (and rollup). To avoid breaking existing deployments of the cube extension it has not been renamed, neither has cube been made a reserved keyword. Instead precedence hacking is used to make GROUP BY cube(..) refer to the CUBE grouping sets feature, and not the function cube(). To actually group by a function cube(), unlikely as that might be, the function name has to be quoted. Needs a catversion bump because stored rules may change. Author: Andrew Gierth and Atri Sharma, with contributions from Andres Freund Reviewed-By: Andres Freund, Noah Misch, Tom Lane, Svenne Krap, Tomas Vondra, Erik Rijkers, Marti Raudsepp, Pavel Stehule Discussion: CAOeZVidmVRe2jU6aMk_5qkxnB7dfmPROzM7Ur8JPW5j8Y5X-Lw@mail.gmail.com
2015-05-16 03:40:59 +02:00
/*
* Explain a property that takes the form of a list of unlabeled items within
* another list. "data" is a list of C strings.
*/
void
ExplainPropertyListNested(const char *qlabel, List *data, ExplainState *es)
{
ListCell *lc;
bool first = true;
switch (es->format)
{
case EXPLAIN_FORMAT_TEXT:
case EXPLAIN_FORMAT_XML:
ExplainPropertyList(qlabel, data, es);
return;
case EXPLAIN_FORMAT_JSON:
ExplainJSONLineEnding(es);
appendStringInfoSpaces(es->str, es->indent * 2);
appendStringInfoChar(es->str, '[');
foreach(lc, data)
{
if (!first)
appendStringInfoString(es->str, ", ");
escape_json(es->str, (const char *) lfirst(lc));
first = false;
}
appendStringInfoChar(es->str, ']');
break;
case EXPLAIN_FORMAT_YAML:
ExplainYAMLLineStarting(es);
appendStringInfoString(es->str, "- [");
foreach(lc, data)
{
if (!first)
appendStringInfoString(es->str, ", ");
escape_yaml(es->str, (const char *) lfirst(lc));
first = false;
}
appendStringInfoChar(es->str, ']');
break;
}
}
/*
* Explain a simple property.
*
* If "numeric" is true, the value is a number (or other value that
* doesn't need quoting in JSON).
*
* This usually should not be invoked directly, but via one of the datatype
* specific routines ExplainPropertyText, ExplainPropertyInteger, etc.
*/
static void
ExplainProperty(const char *qlabel, const char *value, bool numeric,
ExplainState *es)
{
switch (es->format)
{
case EXPLAIN_FORMAT_TEXT:
appendStringInfoSpaces(es->str, es->indent * 2);
appendStringInfo(es->str, "%s: %s\n", qlabel, value);
break;
case EXPLAIN_FORMAT_XML:
{
2010-02-26 03:01:40 +01:00
char *str;
appendStringInfoSpaces(es->str, es->indent * 2);
ExplainXMLTag(qlabel, X_OPENING | X_NOWHITESPACE, es);
str = escape_xml(value);
appendStringInfoString(es->str, str);
pfree(str);
ExplainXMLTag(qlabel, X_CLOSING | X_NOWHITESPACE, es);
appendStringInfoChar(es->str, '\n');
}
break;
case EXPLAIN_FORMAT_JSON:
ExplainJSONLineEnding(es);
appendStringInfoSpaces(es->str, es->indent * 2);
escape_json(es->str, qlabel);
appendStringInfoString(es->str, ": ");
if (numeric)
appendStringInfoString(es->str, value);
else
escape_json(es->str, value);
break;
case EXPLAIN_FORMAT_YAML:
ExplainYAMLLineStarting(es);
appendStringInfo(es->str, "%s: ", qlabel);
if (numeric)
appendStringInfoString(es->str, value);
else
escape_yaml(es->str, value);
break;
}
}
/*
* Explain a string-valued property.
*/
void
ExplainPropertyText(const char *qlabel, const char *value, ExplainState *es)
{
ExplainProperty(qlabel, value, false, es);
}
/*
* Explain an integer-valued property.
*/
void
ExplainPropertyInteger(const char *qlabel, int value, ExplainState *es)
{
2010-02-26 03:01:40 +01:00
char buf[32];
snprintf(buf, sizeof(buf), "%d", value);
ExplainProperty(qlabel, buf, true, es);
}
/*
* Explain a long-integer-valued property.
*/
void
ExplainPropertyLong(const char *qlabel, long value, ExplainState *es)
{
2010-02-26 03:01:40 +01:00
char buf[32];
snprintf(buf, sizeof(buf), "%ld", value);
ExplainProperty(qlabel, buf, true, es);
}
/*
* Explain a float-valued property, using the specified number of
* fractional digits.
*/
void
ExplainPropertyFloat(const char *qlabel, double value, int ndigits,
ExplainState *es)
{
2010-02-26 03:01:40 +01:00
char buf[256];
snprintf(buf, sizeof(buf), "%.*f", ndigits, value);
ExplainProperty(qlabel, buf, true, es);
}
/*
* Explain a bool-valued property.
*/
void
ExplainPropertyBool(const char *qlabel, bool value, ExplainState *es)
{
ExplainProperty(qlabel, value ? "true" : "false", true, es);
}
/*
* Open a group of related objects.
*
* objtype is the type of the group object, labelname is its label within
* a containing object (if any).
*
* If labeled is true, the group members will be labeled properties,
* while if it's false, they'll be unlabeled objects.
*/
static void
ExplainOpenGroup(const char *objtype, const char *labelname,
bool labeled, ExplainState *es)
{
switch (es->format)
{
case EXPLAIN_FORMAT_TEXT:
/* nothing to do */
break;
case EXPLAIN_FORMAT_XML:
ExplainXMLTag(objtype, X_OPENING, es);
es->indent++;
break;
case EXPLAIN_FORMAT_JSON:
ExplainJSONLineEnding(es);
appendStringInfoSpaces(es->str, 2 * es->indent);
if (labelname)
{
escape_json(es->str, labelname);
appendStringInfoString(es->str, ": ");
}
appendStringInfoChar(es->str, labeled ? '{' : '[');
/*
* In JSON format, the grouping_stack is an integer list. 0 means
* we've emitted nothing at this grouping level, 1 means we've
2010-02-26 03:01:40 +01:00
* emitted something (and so the next item needs a comma). See
* ExplainJSONLineEnding().
*/
es->grouping_stack = lcons_int(0, es->grouping_stack);
es->indent++;
break;
case EXPLAIN_FORMAT_YAML:
/*
* In YAML format, the grouping stack is an integer list. 0 means
* we've emitted nothing at this grouping level AND this grouping
* level is unlabelled and must be marked with "- ". See
* ExplainYAMLLineStarting().
*/
ExplainYAMLLineStarting(es);
if (labelname)
{
appendStringInfo(es->str, "%s: ", labelname);
es->grouping_stack = lcons_int(1, es->grouping_stack);
}
else
{
appendStringInfoString(es->str, "- ");
es->grouping_stack = lcons_int(0, es->grouping_stack);
}
es->indent++;
break;
}
}
/*
* Close a group of related objects.
* Parameters must match the corresponding ExplainOpenGroup call.
*/
static void
ExplainCloseGroup(const char *objtype, const char *labelname,
bool labeled, ExplainState *es)
{
switch (es->format)
{
case EXPLAIN_FORMAT_TEXT:
/* nothing to do */
break;
case EXPLAIN_FORMAT_XML:
es->indent--;
ExplainXMLTag(objtype, X_CLOSING, es);
break;
case EXPLAIN_FORMAT_JSON:
es->indent--;
appendStringInfoChar(es->str, '\n');
appendStringInfoSpaces(es->str, 2 * es->indent);
appendStringInfoChar(es->str, labeled ? '}' : ']');
es->grouping_stack = list_delete_first(es->grouping_stack);
break;
case EXPLAIN_FORMAT_YAML:
es->indent--;
es->grouping_stack = list_delete_first(es->grouping_stack);
break;
}
}
/*
* Emit a "dummy" group that never has any members.
*
* objtype is the type of the group object, labelname is its label within
* a containing object (if any).
*/
static void
ExplainDummyGroup(const char *objtype, const char *labelname, ExplainState *es)
{
switch (es->format)
{
case EXPLAIN_FORMAT_TEXT:
/* nothing to do */
break;
case EXPLAIN_FORMAT_XML:
ExplainXMLTag(objtype, X_CLOSE_IMMEDIATE, es);
break;
case EXPLAIN_FORMAT_JSON:
ExplainJSONLineEnding(es);
appendStringInfoSpaces(es->str, 2 * es->indent);
if (labelname)
{
escape_json(es->str, labelname);
appendStringInfoString(es->str, ": ");
}
escape_json(es->str, objtype);
break;
case EXPLAIN_FORMAT_YAML:
ExplainYAMLLineStarting(es);
if (labelname)
{
escape_yaml(es->str, labelname);
appendStringInfoString(es->str, ": ");
}
else
{
appendStringInfoString(es->str, "- ");
}
escape_yaml(es->str, objtype);
break;
}
}
/*
* Emit the start-of-output boilerplate.
*
* This is just enough different from processing a subgroup that we need
* a separate pair of subroutines.
*/
void
ExplainBeginOutput(ExplainState *es)
{
switch (es->format)
{
case EXPLAIN_FORMAT_TEXT:
/* nothing to do */
break;
case EXPLAIN_FORMAT_XML:
appendStringInfoString(es->str,
"<explain xmlns=\"http://www.postgresql.org/2009/explain\">\n");
es->indent++;
break;
case EXPLAIN_FORMAT_JSON:
/* top-level structure is an array of plans */
appendStringInfoChar(es->str, '[');
es->grouping_stack = lcons_int(0, es->grouping_stack);
es->indent++;
break;
case EXPLAIN_FORMAT_YAML:
es->grouping_stack = lcons_int(0, es->grouping_stack);
break;
}
}
/*
* Emit the end-of-output boilerplate.
*/
void
ExplainEndOutput(ExplainState *es)
{
switch (es->format)
{
case EXPLAIN_FORMAT_TEXT:
/* nothing to do */
break;
case EXPLAIN_FORMAT_XML:
es->indent--;
appendStringInfoString(es->str, "</explain>");
break;
case EXPLAIN_FORMAT_JSON:
es->indent--;
appendStringInfoString(es->str, "\n]");
es->grouping_stack = list_delete_first(es->grouping_stack);
break;
case EXPLAIN_FORMAT_YAML:
es->grouping_stack = list_delete_first(es->grouping_stack);
break;
}
}
/*
* Put an appropriate separator between multiple plans
*/
void
ExplainSeparatePlans(ExplainState *es)
{
switch (es->format)
{
case EXPLAIN_FORMAT_TEXT:
/* add a blank line */
appendStringInfoChar(es->str, '\n');
break;
case EXPLAIN_FORMAT_XML:
case EXPLAIN_FORMAT_JSON:
case EXPLAIN_FORMAT_YAML:
/* nothing to do */
break;
}
}
/*
* Emit opening or closing XML tag.
*
* "flags" must contain X_OPENING, X_CLOSING, or X_CLOSE_IMMEDIATE.
* Optionally, OR in X_NOWHITESPACE to suppress the whitespace we'd normally
* add.
*
* XML restricts tag names more than our other output formats, eg they can't
* contain white space or slashes. Replace invalid characters with dashes,
* so that for example "I/O Read Time" becomes "I-O-Read-Time".
*/
static void
ExplainXMLTag(const char *tagname, int flags, ExplainState *es)
{
const char *s;
const char *valid = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_.";
if ((flags & X_NOWHITESPACE) == 0)
appendStringInfoSpaces(es->str, 2 * es->indent);
appendStringInfoCharMacro(es->str, '<');
if ((flags & X_CLOSING) != 0)
appendStringInfoCharMacro(es->str, '/');
for (s = tagname; *s; s++)
appendStringInfoChar(es->str, strchr(valid, *s) ? *s : '-');
if ((flags & X_CLOSE_IMMEDIATE) != 0)
appendStringInfoString(es->str, " /");
appendStringInfoCharMacro(es->str, '>');
if ((flags & X_NOWHITESPACE) == 0)
appendStringInfoCharMacro(es->str, '\n');
}
/*
* Emit a JSON line ending.
*
* JSON requires a comma after each property but the last. To facilitate this,
* in JSON format, the text emitted for each property begins just prior to the
* preceding line-break (and comma, if applicable).
*/
static void
ExplainJSONLineEnding(ExplainState *es)
{
Assert(es->format == EXPLAIN_FORMAT_JSON);
if (linitial_int(es->grouping_stack) != 0)
appendStringInfoChar(es->str, ',');
else
linitial_int(es->grouping_stack) = 1;
appendStringInfoChar(es->str, '\n');
}
/*
* Indent a YAML line.
*
* YAML lines are ordinarily indented by two spaces per indentation level.
* The text emitted for each property begins just prior to the preceding
* line-break, except for the first property in an unlabelled group, for which
* it begins immediately after the "- " that introduces the group. The first
* property of the group appears on the same line as the opening "- ".
*/
static void
ExplainYAMLLineStarting(ExplainState *es)
{
Assert(es->format == EXPLAIN_FORMAT_YAML);
if (linitial_int(es->grouping_stack) == 0)
{
linitial_int(es->grouping_stack) = 1;
}
else
{
appendStringInfoChar(es->str, '\n');
appendStringInfoSpaces(es->str, es->indent * 2);
}
}
/*
* YAML is a superset of JSON; unfortunately, the YAML quoting rules are
* ridiculously complicated -- as documented in sections 5.3 and 7.3.3 of
* http://yaml.org/spec/1.2/spec.html -- so we chose to just quote everything.
* Empty strings, strings with leading or trailing whitespace, and strings
* containing a variety of special characters must certainly be quoted or the
* output is invalid; and other seemingly harmless strings like "0xa" or
* "true" must be quoted, lest they be interpreted as a hexadecimal or Boolean
* constant rather than a string.
*/
static void
escape_yaml(StringInfo buf, const char *str)
{
escape_json(buf, str);
}