rdelaage
/
postgresql
mirror of https://git.postgresql.org/git/postgresql.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity
postgresql/src/include/commands/prepare.h

60 lines
2.1 KiB
C
Raw Normal View History

PREPARE/EXECUTE statements. Patch by Neil Conway, some kibitzing from Tom Lane.
2002-08-27 06:55:12 +02:00
/*-------------------------------------------------------------------------
*
* prepare.h
Extended query protocol: parse, bind, execute, describe FE/BE messages. Only lightly tested as yet, since libpq doesn't know anything about 'em.
2003-05-05 02:44:56 +02:00
* PREPARE, EXECUTE and DEALLOCATE commands, and prepared-stmt storage
PREPARE/EXECUTE statements. Patch by Neil Conway, some kibitzing from Tom Lane.
2002-08-27 06:55:12 +02:00
*
*
Update copyright via script for 2017
2017-01-03 19:48:53 +01:00
* Copyright (c) 2002-2017, PostgreSQL Global Development Group
PREPARE/EXECUTE statements. Patch by Neil Conway, some kibitzing from Tom Lane.
2002-08-27 06:55:12 +02:00
*
Remove cvs keywords from all files.
2010-09-20 22:08:53 +02:00
* src/include/commands/prepare.h
PREPARE/EXECUTE statements. Patch by Neil Conway, some kibitzing from Tom Lane.
2002-08-27 06:55:12 +02:00
*
*-------------------------------------------------------------------------
*/
#ifndef PREPARE_H
#define PREPARE_H
Extend EXPLAIN to allow generic options to be specified. The original syntax made it difficult to add options without making them into reserved words. This change parenthesizes the options to avoid that problem, and makes provision for an explicit (and perhaps non-Boolean) value for each option. The original syntax is still supported, but only for the two original options ANALYZE and VERBOSE. As a test case, add a COSTS option that can suppress the planner cost estimates. This may be useful for including EXPLAIN output in the regression tests, which are otherwise unable to cope with cross-platform variations in cost estimates. Robert Haas
2009-07-27 01:34:18 +02:00
#include "commands/explain.h"
Split heapam_xlog.h from heapam.h The heapam XLog functions are used by other modules, not all of which are interested in the rest of the heapam API. With this, we let them get just the XLog stuff in which they are interested and not pollute them with unrelated includes. Also, since heapam.h no longer requires xlog.h, many files that do include heapam.h no longer get xlog.h automatically, including a few headers. This is useful because heapam.h is getting pulled in by execnodes.h, which is in turn included by a lot of files.
2012-08-29 01:02:00 +02:00
#include "datatype/timestamp.h"
First phase of plan-invalidation project: create a plan cache management module and teach PREPARE and protocol-level prepared statements to use it. In service of this, rearrange utility-statement processing so that parse analysis does not assume table schemas can't change before execution for utility statements (necessary because we don't attempt to re-acquire locks for utility statements when reusing a stored plan). This requires some refactoring of the ProcessUtility API, but it ends up cleaner anyway, for instance we can get rid of the QueryContext global. Still to do: fix up SPI and related code to use the plan cache; I'm tempted to try to make SQL functions use it too. Also, there are at least some aspects of system state that we want to ensure remain the same during a replan as in the original processing; search_path certainly ought to behave that way for instance, and perhaps there are others.
2007-03-13 01:33:44 +01:00
#include "utils/plancache.h"
PREPARE/EXECUTE statements. Patch by Neil Conway, some kibitzing from Tom Lane.
2002-08-27 06:55:12 +02:00
Extended query protocol: parse, bind, execute, describe FE/BE messages. Only lightly tested as yet, since libpq doesn't know anything about 'em.
2003-05-05 02:44:56 +02:00
/*
First phase of plan-invalidation project: create a plan cache management module and teach PREPARE and protocol-level prepared statements to use it. In service of this, rearrange utility-statement processing so that parse analysis does not assume table schemas can't change before execution for utility statements (necessary because we don't attempt to re-acquire locks for utility statements when reusing a stored plan). This requires some refactoring of the ProcessUtility API, but it ends up cleaner anyway, for instance we can get rid of the QueryContext global. Still to do: fix up SPI and related code to use the plan cache; I'm tempted to try to make SQL functions use it too. Also, there are at least some aspects of system state that we want to ensure remain the same during a replan as in the original processing; search_path certainly ought to behave that way for instance, and perhaps there are others.
2007-03-13 01:33:44 +01:00
* The data structure representing a prepared statement. This is now just
* a thin veneer over a plancache entry --- the main addition is that of
* a name.
Extended query protocol: parse, bind, execute, describe FE/BE messages. Only lightly tested as yet, since libpq doesn't know anything about 'em.
2003-05-05 02:44:56 +02:00
*
First phase of plan-invalidation project: create a plan cache management module and teach PREPARE and protocol-level prepared statements to use it. In service of this, rearrange utility-statement processing so that parse analysis does not assume table schemas can't change before execution for utility statements (necessary because we don't attempt to re-acquire locks for utility statements when reusing a stored plan). This requires some refactoring of the ProcessUtility API, but it ends up cleaner anyway, for instance we can get rid of the QueryContext global. Still to do: fix up SPI and related code to use the plan cache; I'm tempted to try to make SQL functions use it too. Also, there are at least some aspects of system state that we want to ensure remain the same during a replan as in the original processing; search_path certainly ought to behave that way for instance, and perhaps there are others.
2007-03-13 01:33:44 +01:00
* Note: all subsidiary storage lives in the referenced plancache entry.
Extended query protocol: parse, bind, execute, describe FE/BE messages. Only lightly tested as yet, since libpq doesn't know anything about 'em.
2003-05-05 02:44:56 +02:00
*/
typedef struct
{
/* dynahash.c requires key to be first field */
pgindent run for 8.2.
2006-10-04 02:30:14 +02:00
char stmt_name[NAMEDATALEN];
pgindent run for 8.3.
2007-11-15 22:14:46 +01:00
CachedPlanSource *plansource; /* the actual cached plan */
Remove the Query structure from the executor's API. This allows us to stop storing mostly-redundant Query trees in prepared statements, portals, etc. To replace Query, a new node type called PlannedStmt is inserted by the planner at the top of a completed plan tree; this carries just the fields of Query that are still needed at runtime. The statement lists kept in portals etc. now consist of intermixed PlannedStmt and bare utility-statement nodes --- no Query. This incidentally allows us to remove some fields from Query and Plan nodes that shouldn't have been there in the first place. Still to do: simplify the execution-time range table; at the moment the range table passed to the executor still contains Query trees for subqueries. initdb forced due to change of stored rules.
2007-02-20 18:32:18 +01:00
bool from_sql; /* prepared via SQL, not FE/BE protocol? */
pgindent run for 8.2.
2006-10-04 02:30:14 +02:00
TimestampTz prepare_time; /* the time when the stmt was prepared */
Another pgindent run with updated typedefs.
2003-08-08 23:42:59 +02:00
} PreparedStatement;
Extended query protocol: parse, bind, execute, describe FE/BE messages. Only lightly tested as yet, since libpq doesn't know anything about 'em.
2003-05-05 02:44:56 +02:00
/* Utility statements PREPARE, EXECUTE, DEALLOCATE, EXPLAIN EXECUTE */
First phase of plan-invalidation project: create a plan cache management module and teach PREPARE and protocol-level prepared statements to use it. In service of this, rearrange utility-statement processing so that parse analysis does not assume table schemas can't change before execution for utility statements (necessary because we don't attempt to re-acquire locks for utility statements when reusing a stored plan). This requires some refactoring of the ProcessUtility API, but it ends up cleaner anyway, for instance we can get rid of the QueryContext global. Still to do: fix up SPI and related code to use the plan cache; I'm tempted to try to make SQL functions use it too. Also, there are at least some aspects of system state that we want to ensure remain the same during a replan as in the original processing; search_path certainly ought to behave that way for instance, and perhaps there are others.
2007-03-13 01:33:44 +01:00
extern void PrepareQuery(PrepareStmt *stmt, const char *queryString);
Restructure SELECT INTO's parsetree representation into CreateTableAsStmt. Making this operation look like a utility statement seems generally a good idea, and particularly so in light of the desire to provide command triggers for utility statements. The original choice of representing it as SELECT with an IntoClause appendage had metastasized into rather a lot of places, unfortunately, so that this patch is a great deal more complicated than one might at first expect. In particular, keeping EXPLAIN working for SELECT INTO and CREATE TABLE AS subcommands required restructuring some EXPLAIN-related APIs. Add-on code that calls ExplainOnePlan or ExplainOneUtility, or uses ExplainOneQuery_hook, will need adjustment. Also, the cases PREPARE ... SELECT INTO and CREATE RULE ... SELECT INTO, which formerly were accepted though undocumented, are no longer accepted. The PREPARE case can be replaced with use of CREATE TABLE AS EXECUTE. The CREATE RULE case doesn't seem to have much real-world use (since the rule would work only once before failing with "table already exists"), so we'll not bother with that one. Both SELECT INTO and CREATE TABLE AS still return a command tag of "SELECT nnnn". There was some discussion of returning "CREATE TABLE nnnn", but for the moment backwards compatibility wins the day. Andres Freund and Tom Lane
2012-03-20 02:37:19 +01:00
extern void ExecuteQuery(ExecuteStmt *stmt, IntoClause *intoClause,
const char *queryString, ParamListInfo params,
pgindent run for 8.2.
2006-10-04 02:30:14 +02:00
DestReceiver *dest, char *completionTag);
PREPARE/EXECUTE statements. Patch by Neil Conway, some kibitzing from Tom Lane.
2002-08-27 06:55:12 +02:00
extern void DeallocateQuery(DeallocateStmt *stmt);
Restructure SELECT INTO's parsetree representation into CreateTableAsStmt. Making this operation look like a utility statement seems generally a good idea, and particularly so in light of the desire to provide command triggers for utility statements. The original choice of representing it as SELECT with an IntoClause appendage had metastasized into rather a lot of places, unfortunately, so that this patch is a great deal more complicated than one might at first expect. In particular, keeping EXPLAIN working for SELECT INTO and CREATE TABLE AS subcommands required restructuring some EXPLAIN-related APIs. Add-on code that calls ExplainOnePlan or ExplainOneUtility, or uses ExplainOneQuery_hook, will need adjustment. Also, the cases PREPARE ... SELECT INTO and CREATE RULE ... SELECT INTO, which formerly were accepted though undocumented, are no longer accepted. The PREPARE case can be replaced with use of CREATE TABLE AS EXECUTE. The CREATE RULE case doesn't seem to have much real-world use (since the rule would work only once before failing with "table already exists"), so we'll not bother with that one. Both SELECT INTO and CREATE TABLE AS still return a command tag of "SELECT nnnn". There was some discussion of returning "CREATE TABLE nnnn", but for the moment backwards compatibility wins the day. Andres Freund and Tom Lane
2012-03-20 02:37:19 +01:00
extern void ExplainExecuteQuery(ExecuteStmt *execstmt, IntoClause *into,
ExplainState *es,
Extend EXPLAIN to allow generic options to be specified. The original syntax made it difficult to add options without making them into reserved words. This change parenthesizes the options to avoid that problem, and makes provision for an explicit (and perhaps non-Boolean) value for each option. The original syntax is still supported, but only for the two original options ANALYZE and VERBOSE. As a test case, add a COSTS option that can suppress the planner cost estimates. This may be useful for including EXPLAIN output in the regression tests, which are otherwise unable to cope with cross-platform variations in cost estimates. Robert Haas
2009-07-27 01:34:18 +02:00
const char *queryString, ParamListInfo params);
PREPARE/EXECUTE statements. Patch by Neil Conway, some kibitzing from Tom Lane.
2002-08-27 06:55:12 +02:00
Extended query protocol: parse, bind, execute, describe FE/BE messages. Only lightly tested as yet, since libpq doesn't know anything about 'em.
2003-05-05 02:44:56 +02:00
/* Low-level access to stored prepared statements */
extern void StorePreparedStatement(const char *stmt_name,
Redesign the plancache mechanism for more flexibility and efficiency. Rewrite plancache.c so that a "cached plan" (which is rather a misnomer at this point) can support generation of custom, parameter-value-dependent plans, and can make an intelligent choice between using custom plans and the traditional generic-plan approach. The specific choice algorithm implemented here can probably be improved in future, but this commit is all about getting the mechanism in place, not the policy. In addition, restructure the API to greatly reduce the amount of extraneous data copying needed. The main compromise needed to make that possible was to split the initial creation of a CachedPlanSource into two steps. It's worth noting in particular that SPI_saveplan is now deprecated in favor of SPI_keepplan, which accomplishes the same end result with zero data copying, and no need to then spend even more cycles throwing away the original SPIPlan. The risk of long-term memory leaks while manipulating SPIPlans has also been greatly reduced. Most of this improvement is based on use of the recently-added MemoryContextSetParent primitive.
2011-09-16 06:42:53 +02:00
CachedPlanSource *plansource,
Add a new system view, pg_prepared_statements, that can be used to access information about the prepared statements that are available in the current session. Original patch from Joachim Wieland, various improvements by Neil Conway. The "statement" column of the view contains the literal query string sent by the client, without any rewriting or pretty printing. This means that prepared statements created via SQL will be prefixed with "PREPARE ... AS ", whereas those prepared via the FE/BE protocol will not. That is unfortunate, but discussion on -patches did not yield an efficient way to improve this, and there is some merit in returning exactly what the client sent to the backend. Catalog version bumped, regression tests updated.
2006-01-08 08:00:27 +01:00
bool from_sql);
Extended query protocol: parse, bind, execute, describe FE/BE messages. Only lightly tested as yet, since libpq doesn't know anything about 'em.
2003-05-05 02:44:56 +02:00
extern PreparedStatement *FetchPreparedStatement(const char *stmt_name,
pgindent run.
2003-08-04 02:43:34 +02:00
bool throwError);
Extended query protocol: parse, bind, execute, describe FE/BE messages. Only lightly tested as yet, since libpq doesn't know anything about 'em.
2003-05-05 02:44:56 +02:00
extern void DropPreparedStatement(const char *stmt_name, bool showError);
Another pgindent run with updated typedefs.
2003-08-08 23:42:59 +02:00
extern TupleDesc FetchPreparedStatementResultDesc(PreparedStatement *stmt);
Fix the mechanism for reporting the original table OID and column number of columns of a query result so that it can "see through" cursors and prepared statements. Per gripe a couple months back from John DeSoi.
2005-06-22 19:45:46 +02:00
extern List *FetchPreparedStatementTargetList(PreparedStatement *stmt);
Extended query protocol: parse, bind, execute, describe FE/BE messages. Only lightly tested as yet, since libpq doesn't know anything about 'em.
2003-05-05 02:44:56 +02:00
Restructure SELECT INTO's parsetree representation into CreateTableAsStmt. Making this operation look like a utility statement seems generally a good idea, and particularly so in light of the desire to provide command triggers for utility statements. The original choice of representing it as SELECT with an IntoClause appendage had metastasized into rather a lot of places, unfortunately, so that this patch is a great deal more complicated than one might at first expect. In particular, keeping EXPLAIN working for SELECT INTO and CREATE TABLE AS subcommands required restructuring some EXPLAIN-related APIs. Add-on code that calls ExplainOnePlan or ExplainOneUtility, or uses ExplainOneQuery_hook, will need adjustment. Also, the cases PREPARE ... SELECT INTO and CREATE RULE ... SELECT INTO, which formerly were accepted though undocumented, are no longer accepted. The PREPARE case can be replaced with use of CREATE TABLE AS EXECUTE. The CREATE RULE case doesn't seem to have much real-world use (since the rule would work only once before failing with "table already exists"), so we'll not bother with that one. Both SELECT INTO and CREATE TABLE AS still return a command tag of "SELECT nnnn". There was some discussion of returning "CREATE TABLE nnnn", but for the moment backwards compatibility wins the day. Andres Freund and Tom Lane
2012-03-20 02:37:19 +01:00
extern void DropAllPreparedStatements(void);
RESET SESSION, plus related new DDL commands. Patch from Marko Kreen, reviewed by Neil Conway. This patch adds the following DDL command variants: RESET SESSION, RESET TEMP, RESET PLANS, CLOSE ALL, and DEALLOCATE ALL. RESET SESSION is intended for use by connection pool software and the like, in order to reset a client session to something close to its initial state. Note that while most of these command variants can be executed inside a transaction block (but are not transaction-aware!), RESET SESSION cannot. While this is inconsistent, it is intended to catch programmer mistakes: RESET SESSION in an open transaction block is probably unintended.
2007-04-12 08:53:49 +02:00
pgindent run.
2002-09-04 22:31:48 +02:00
#endif /* PREPARE_H */