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postgresql/src/backend/executor/nodeFunctionscan.c

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First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
/*-------------------------------------------------------------------------
*
* nodeFunctionscan.c
* Support routines for scanning RangeFunctions (functions in rangetable).
*
Update copyright for 2018 Backpatch-through: certain files through 9.3
2018-01-03 05:30:12 +01:00
* Portions Copyright (c) 1996-2018, PostgreSQL Global Development Group
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
Remove cvs keywords from all files.
2010-09-20 22:08:53 +02:00
* src/backend/executor/nodeFunctionscan.c
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
*
*-------------------------------------------------------------------------
*/
/*
* INTERFACE ROUTINES
* ExecFunctionScan scans a function.
* ExecFunctionNext retrieve next tuple in sequential order.
* ExecInitFunctionScan creates and initializes a functionscan node.
* ExecEndFunctionScan releases any storage allocated.
Make NestLoop plan nodes pass outer-relation variables into their inner relation using the general PARAM_EXEC executor parameter mechanism, rather than the ad-hoc kluge of passing the outer tuple down through ExecReScan. The previous method was hard to understand and could never be extended to handle parameters coming from multiple join levels. This patch doesn't change the set of possible plans nor have any significant performance effect, but it's necessary infrastructure for future generalization of the concept of an inner indexscan plan. ExecReScan's second parameter is now unused, so it's removed.
2010-07-12 19:01:06 +02:00
* ExecReScanFunctionScan rescans the function
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
*/
#include "postgres.h"
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
#include "catalog/pg_type.h"
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
#include "executor/nodeFunctionscan.h"
First phase of OUT-parameters project. We can now define and use SQL functions with OUT parameters. The various PLs still need work, as does pg_dump. Rudimentary docs and regression tests included.
2005-04-01 00:46:33 +02:00
#include "funcapi.h"
Per-column collation support This adds collation support for columns and domains, a COLLATE clause to override it per expression, and B-tree index support. Peter Eisentraut reviewed by Pavel Stehule, Itagaki Takahiro, Robert Haas, Noah Misch
2011-02-08 22:04:18 +01:00
#include "nodes/nodeFuncs.h"
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
#include "utils/builtins.h"
Avoid leaking memory while evaluating arguments for a table function. ExecMakeTableFunctionResult evaluated the arguments for a function-in-FROM in the query-lifespan memory context. This is insignificant in simple cases where the function relation is scanned only once; but if the function is in a sub-SELECT or is on the inside of a nested loop, any memory consumed during argument evaluation can add up quickly. (The potential for trouble here had been foreseen long ago, per existing comments; but we'd not previously seen a complaint from the field about it.) To fix, create an additional temporary context just for this purpose. Per an example from MauMau. Back-patch to all active branches.
2014-06-20 04:13:41 +02:00
#include "utils/memutils.h"
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
/*
* Runtime data for each function being scanned.
*/
typedef struct FunctionScanPerFuncState
{
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
SetExprState *setexpr; /* state of the expression being evaluated */
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
TupleDesc tupdesc; /* desc of the function result type */
int colcount; /* expected number of result columns */
Tuplestorestate *tstore; /* holds the function result set */
int64 rowcount; /* # of rows in result set, -1 if not known */
TupleTableSlot *func_slot; /* function result slot (or NULL) */
} FunctionScanPerFuncState;
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
Phase 1 of read-only-plans project: cause executor state nodes to point to plan nodes, not vice-versa. All executor state nodes now inherit from struct PlanState. Copying of plan trees has been simplified by not storing a list of SubPlans in Plan nodes (eliminating duplicate links). The executor still needs such a list, but it can build it during ExecutorStart since it has to scan the plan tree anyway. No initdb forced since no stored-on-disk structures changed, but you will need a full recompile because of node-numbering changes.
2002-12-05 16:50:39 +01:00
static TupleTableSlot *FunctionNext(FunctionScanState *node);
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
/* ----------------------------------------------------------------
* Scan Support
* ----------------------------------------------------------------
*/
/* ----------------------------------------------------------------
* FunctionNext
*
* This is a workhorse for ExecFunctionScan
* ----------------------------------------------------------------
*/
static TupleTableSlot *
Phase 1 of read-only-plans project: cause executor state nodes to point to plan nodes, not vice-versa. All executor state nodes now inherit from struct PlanState. Copying of plan trees has been simplified by not storing a list of SubPlans in Plan nodes (eliminating duplicate links). The executor still needs such a list, but it can build it during ExecutorStart since it has to scan the plan tree anyway. No initdb forced since no stored-on-disk structures changed, but you will need a full recompile because of node-numbering changes.
2002-12-05 16:50:39 +01:00
FunctionNext(FunctionScanState *node)
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
{
pgindent run.
2002-09-04 22:31:48 +02:00
EState *estate;
ScanDirection direction;
Add SQL Standard WITH ORDINALITY support for UNNEST (and any other SRF) Author: Andrew Gierth, David Fetter Reviewers: Dean Rasheed, Jeevan Chalke, Stephen Frost
2013-07-29 17:38:01 +02:00
TupleTableSlot *scanslot;
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
bool alldone;
int64 oldpos;
int funcno;
int att;
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
/*
* get information from the estate and scan state
*/
Phase 1 of read-only-plans project: cause executor state nodes to point to plan nodes, not vice-versa. All executor state nodes now inherit from struct PlanState. Copying of plan trees has been simplified by not storing a list of SubPlans in Plan nodes (eliminating duplicate links). The executor still needs such a list, but it can build it during ExecutorStart since it has to scan the plan tree anyway. No initdb forced since no stored-on-disk structures changed, but you will need a full recompile because of node-numbering changes.
2002-12-05 16:50:39 +01:00
estate = node->ss.ps.state;
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
direction = estate->es_direction;
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
scanslot = node->ss.ss_ScanTupleSlot;
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
if (node->simple)
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
{
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
/*
* Fast path for the trivial case: the function return type and scan
* result type are the same, so we fetch the function result straight
* into the scan result slot. No need to update ordinality or
* rowcounts either.
*/
Tuplestorestate *tstore = node->funcstates[0].tstore;
Add SQL Standard WITH ORDINALITY support for UNNEST (and any other SRF) Author: Andrew Gierth, David Fetter Reviewers: Dean Rasheed, Jeevan Chalke, Stephen Frost
2013-07-29 17:38:01 +02:00
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
/*
* If first time through, read all tuples from function and put them
* in a tuplestore. Subsequent calls just fetch tuples from
* tuplestore.
*/
if (tstore == NULL)
{
node->funcstates[0].tstore = tstore =
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
ExecMakeTableFunctionResult(node->funcstates[0].setexpr,
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
node->ss.ps.ps_ExprContext,
Avoid leaking memory while evaluating arguments for a table function. ExecMakeTableFunctionResult evaluated the arguments for a function-in-FROM in the query-lifespan memory context. This is insignificant in simple cases where the function relation is scanned only once; but if the function is in a sub-SELECT or is on the inside of a nested loop, any memory consumed during argument evaluation can add up quickly. (The potential for trouble here had been foreseen long ago, per existing comments; but we'd not previously seen a complaint from the field about it.) To fix, create an additional temporary context just for this purpose. Per an example from MauMau. Back-patch to all active branches.
2014-06-20 04:13:41 +02:00
node->argcontext,
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
node->funcstates[0].tupdesc,
Phase 3 of pgindent updates. Don't move parenthesized lines to the left, even if that means they flow past the right margin. By default, BSD indent lines up statement continuation lines that are within parentheses so that they start just to the right of the preceding left parenthesis. However, traditionally, if that resulted in the continuation line extending to the right of the desired right margin, then indent would push it left just far enough to not overrun the margin, if it could do so without making the continuation line start to the left of the current statement indent. That makes for a weird mix of indentations unless one has been completely rigid about never violating the 80-column limit. This behavior has been pretty universally panned by Postgres developers. Hence, disable it with indent's new -lpl switch, so that parenthesized lines are always lined up with the preceding left paren. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-06-21 21:35:54 +02:00
node->eflags & EXEC_FLAG_BACKWARD);
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
/*
* paranoia - cope if the function, which may have constructed the
* tuplestore itself, didn't leave it pointing at the start. This
* call is fast, so the overhead shouldn't be an issue.
*/
tuplestore_rescan(tstore);
}
Add SQL Standard WITH ORDINALITY support for UNNEST (and any other SRF) Author: Andrew Gierth, David Fetter Reviewers: Dean Rasheed, Jeevan Chalke, Stephen Frost
2013-07-29 17:38:01 +02:00
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
/*
* Get the next tuple from tuplestore.
*/
(void) tuplestore_gettupleslot(tstore,
ScanDirectionIsForward(direction),
false,
scanslot);
return scanslot;
}
Add SQL Standard WITH ORDINALITY support for UNNEST (and any other SRF) Author: Andrew Gierth, David Fetter Reviewers: Dean Rasheed, Jeevan Chalke, Stephen Frost
2013-07-29 17:38:01 +02:00
/*
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
* Increment or decrement ordinal counter before checking for end-of-data,
* so that we can move off either end of the result by 1 (and no more than
* 1) without losing correct count. See PortalRunSelect for why we can
* assume that we won't be called repeatedly in the end-of-data state.
Add SQL Standard WITH ORDINALITY support for UNNEST (and any other SRF) Author: Andrew Gierth, David Fetter Reviewers: Dean Rasheed, Jeevan Chalke, Stephen Frost
2013-07-29 17:38:01 +02:00
*/
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
oldpos = node->ordinal;
Add SQL Standard WITH ORDINALITY support for UNNEST (and any other SRF) Author: Andrew Gierth, David Fetter Reviewers: Dean Rasheed, Jeevan Chalke, Stephen Frost
2013-07-29 17:38:01 +02:00
if (ScanDirectionIsForward(direction))
node->ordinal++;
else
node->ordinal--;
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
/*
* Main loop over functions.
*
* We fetch the function results into func_slots (which match the function
* return types), and then copy the values to scanslot (which matches the
* scan result type), setting the ordinal column (if any) as well.
*/
ExecClearTuple(scanslot);
att = 0;
alldone = true;
for (funcno = 0; funcno < node->nfuncs; funcno++)
Add SQL Standard WITH ORDINALITY support for UNNEST (and any other SRF) Author: Andrew Gierth, David Fetter Reviewers: Dean Rasheed, Jeevan Chalke, Stephen Frost
2013-07-29 17:38:01 +02:00
{
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
FunctionScanPerFuncState *fs = &node->funcstates[funcno];
int i;
Add SQL Standard WITH ORDINALITY support for UNNEST (and any other SRF) Author: Andrew Gierth, David Fetter Reviewers: Dean Rasheed, Jeevan Chalke, Stephen Frost
2013-07-29 17:38:01 +02:00
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
/*
* If first time through, read all tuples from function and put them
* in a tuplestore. Subsequent calls just fetch tuples from
* tuplestore.
*/
if (fs->tstore == NULL)
{
fs->tstore =
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
ExecMakeTableFunctionResult(fs->setexpr,
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
node->ss.ps.ps_ExprContext,
Avoid leaking memory while evaluating arguments for a table function. ExecMakeTableFunctionResult evaluated the arguments for a function-in-FROM in the query-lifespan memory context. This is insignificant in simple cases where the function relation is scanned only once; but if the function is in a sub-SELECT or is on the inside of a nested loop, any memory consumed during argument evaluation can add up quickly. (The potential for trouble here had been foreseen long ago, per existing comments; but we'd not previously seen a complaint from the field about it.) To fix, create an additional temporary context just for this purpose. Per an example from MauMau. Back-patch to all active branches.
2014-06-20 04:13:41 +02:00
node->argcontext,
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
fs->tupdesc,
Phase 3 of pgindent updates. Don't move parenthesized lines to the left, even if that means they flow past the right margin. By default, BSD indent lines up statement continuation lines that are within parentheses so that they start just to the right of the preceding left parenthesis. However, traditionally, if that resulted in the continuation line extending to the right of the desired right margin, then indent would push it left just far enough to not overrun the margin, if it could do so without making the continuation line start to the left of the current statement indent. That makes for a weird mix of indentations unless one has been completely rigid about never violating the 80-column limit. This behavior has been pretty universally panned by Postgres developers. Hence, disable it with indent's new -lpl switch, so that parenthesized lines are always lined up with the preceding left paren. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-06-21 21:35:54 +02:00
node->eflags & EXEC_FLAG_BACKWARD);
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
/*
* paranoia - cope if the function, which may have constructed the
* tuplestore itself, didn't leave it pointing at the start. This
* call is fast, so the overhead shouldn't be an issue.
*/
tuplestore_rescan(fs->tstore);
}
Add SQL Standard WITH ORDINALITY support for UNNEST (and any other SRF) Author: Andrew Gierth, David Fetter Reviewers: Dean Rasheed, Jeevan Chalke, Stephen Frost
2013-07-29 17:38:01 +02:00
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
/*
* Get the next tuple from tuplestore.
*
* If we have a rowcount for the function, and we know the previous
* read position was out of bounds, don't try the read. This allows
* backward scan to work when there are mixed row counts present.
*/
if (fs->rowcount != -1 && fs->rowcount < oldpos)
ExecClearTuple(fs->func_slot);
else
(void) tuplestore_gettupleslot(fs->tstore,
ScanDirectionIsForward(direction),
false,
fs->func_slot);
if (TupIsNull(fs->func_slot))
Add SQL Standard WITH ORDINALITY support for UNNEST (and any other SRF) Author: Andrew Gierth, David Fetter Reviewers: Dean Rasheed, Jeevan Chalke, Stephen Frost
2013-07-29 17:38:01 +02:00
{
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
/*
* If we ran out of data for this function in the forward
* direction then we now know how many rows it returned. We need
* to know this in order to handle backwards scans. The row count
* we store is actually 1+ the actual number, because we have to
* position the tuplestore 1 off its end sometimes.
*/
if (ScanDirectionIsForward(direction) && fs->rowcount == -1)
fs->rowcount = node->ordinal;
/*
* populate the result cols with nulls
*/
for (i = 0; i < fs->colcount; i++)
{
scanslot->tts_values[att] = (Datum) 0;
scanslot->tts_isnull[att] = true;
att++;
}
Add SQL Standard WITH ORDINALITY support for UNNEST (and any other SRF) Author: Andrew Gierth, David Fetter Reviewers: Dean Rasheed, Jeevan Chalke, Stephen Frost
2013-07-29 17:38:01 +02:00
}
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
else
{
/*
* we have a result, so just copy it to the result cols.
*/
slot_getallattrs(fs->func_slot);
for (i = 0; i < fs->colcount; i++)
{
scanslot->tts_values[att] = fs->func_slot->tts_values[i];
scanslot->tts_isnull[att] = fs->func_slot->tts_isnull[i];
att++;
}
/*
* We're not done until every function result is exhausted; we pad
* the shorter results with nulls until then.
*/
alldone = false;
}
}
Add SQL Standard WITH ORDINALITY support for UNNEST (and any other SRF) Author: Andrew Gierth, David Fetter Reviewers: Dean Rasheed, Jeevan Chalke, Stephen Frost
2013-07-29 17:38:01 +02:00
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
/*
* ordinal col is always last, per spec.
*/
if (node->ordinality)
{
scanslot->tts_values[att] = Int64GetDatumFast(node->ordinal);
scanslot->tts_isnull[att] = false;
}
Add SQL Standard WITH ORDINALITY support for UNNEST (and any other SRF) Author: Andrew Gierth, David Fetter Reviewers: Dean Rasheed, Jeevan Chalke, Stephen Frost
2013-07-29 17:38:01 +02:00
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
/*
pgindent run for 9.4 This includes removing tabs after periods in C comments, which was applied to back branches, so this change should not effect backpatching.
2014-05-06 18:12:18 +02:00
* If alldone, we just return the previously-cleared scanslot. Otherwise,
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
* finish creating the virtual tuple.
*/
if (!alldone)
Add SQL Standard WITH ORDINALITY support for UNNEST (and any other SRF) Author: Andrew Gierth, David Fetter Reviewers: Dean Rasheed, Jeevan Chalke, Stephen Frost
2013-07-29 17:38:01 +02:00
ExecStoreVirtualTuple(scanslot);
return scanslot;
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
}
Re-implement EvalPlanQual processing to improve its performance and eliminate a lot of strange behaviors that occurred in join cases. We now identify the "current" row for every joined relation in UPDATE, DELETE, and SELECT FOR UPDATE/SHARE queries. If an EvalPlanQual recheck is necessary, we jam the appropriate row into each scan node in the rechecking plan, forcing it to emit only that one row. The former behavior could rescan the whole of each joined relation for each recheck, which was terrible for performance, and what's much worse could result in duplicated output tuples. Also, the original implementation of EvalPlanQual could not re-use the recheck execution tree --- it had to go through a full executor init and shutdown for every row to be tested. To avoid this overhead, I've associated a special runtime Param with each LockRows or ModifyTable plan node, and arranged to make every scan node below such a node depend on that Param. Thus, by signaling a change in that Param, the EPQ machinery can just rescan the already-built test plan. This patch also adds a prohibition on set-returning functions in the targetlist of SELECT FOR UPDATE/SHARE. This is needed to avoid the duplicate-output-tuple problem. It seems fairly reasonable since the other restrictions on SELECT FOR UPDATE are meant to ensure that there is a unique correspondence between source tuples and result tuples, which an output SRF destroys as much as anything else does.
2009-10-26 03:26:45 +01:00
/*
* FunctionRecheck -- access method routine to recheck a tuple in EvalPlanQual
*/
static bool
FunctionRecheck(FunctionScanState *node, TupleTableSlot *slot)
{
/* nothing to check */
return true;
}
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
/* ----------------------------------------------------------------
* ExecFunctionScan(node)
*
Code review for standalone composite types, query-specified composite types, SRFs. Not happy with memory management yet, but I'll commit these other changes.
2002-08-29 02:17:06 +02:00
* Scans the function sequentially and returns the next qualifying
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
* tuple.
Re-implement EvalPlanQual processing to improve its performance and eliminate a lot of strange behaviors that occurred in join cases. We now identify the "current" row for every joined relation in UPDATE, DELETE, and SELECT FOR UPDATE/SHARE queries. If an EvalPlanQual recheck is necessary, we jam the appropriate row into each scan node in the rechecking plan, forcing it to emit only that one row. The former behavior could rescan the whole of each joined relation for each recheck, which was terrible for performance, and what's much worse could result in duplicated output tuples. Also, the original implementation of EvalPlanQual could not re-use the recheck execution tree --- it had to go through a full executor init and shutdown for every row to be tested. To avoid this overhead, I've associated a special runtime Param with each LockRows or ModifyTable plan node, and arranged to make every scan node below such a node depend on that Param. Thus, by signaling a change in that Param, the EPQ machinery can just rescan the already-built test plan. This patch also adds a prohibition on set-returning functions in the targetlist of SELECT FOR UPDATE/SHARE. This is needed to avoid the duplicate-output-tuple problem. It seems fairly reasonable since the other restrictions on SELECT FOR UPDATE are meant to ensure that there is a unique correspondence between source tuples and result tuples, which an output SRF destroys as much as anything else does.
2009-10-26 03:26:45 +01:00
* We call the ExecScan() routine and pass it the appropriate
* access method functions.
* ----------------------------------------------------------------
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
*/
Move ExecProcNode from dispatch to function pointer based model. This allows us to add stack-depth checks the first time an executor node is called, and skip that overhead on following calls. Additionally it yields a nice speedup. While it'd probably have been a good idea to have that check all along, it has become more important after the new expression evaluation framework in b8d7f053c5c2bf2a7e - there's no stack depth check in common paths anymore now. We previously relied on ExecEvalExpr() being executed somewhere. We should move towards that model for further routines, but as this is required for v10, it seems better to only do the necessary (which already is quite large). Author: Andres Freund, Tom Lane Reported-By: Julien Rouhaud Discussion: https://postgr.es/m/22833.1490390175@sss.pgh.pa.us https://postgr.es/m/b0af9eaa-130c-60d0-9e4e-7a135b1e0c76@dalibo.com
2017-07-17 09:33:49 +02:00
static TupleTableSlot *
ExecFunctionScan(PlanState *pstate)
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
{
Move ExecProcNode from dispatch to function pointer based model. This allows us to add stack-depth checks the first time an executor node is called, and skip that overhead on following calls. Additionally it yields a nice speedup. While it'd probably have been a good idea to have that check all along, it has become more important after the new expression evaluation framework in b8d7f053c5c2bf2a7e - there's no stack depth check in common paths anymore now. We previously relied on ExecEvalExpr() being executed somewhere. We should move towards that model for further routines, but as this is required for v10, it seems better to only do the necessary (which already is quite large). Author: Andres Freund, Tom Lane Reported-By: Julien Rouhaud Discussion: https://postgr.es/m/22833.1490390175@sss.pgh.pa.us https://postgr.es/m/b0af9eaa-130c-60d0-9e4e-7a135b1e0c76@dalibo.com
2017-07-17 09:33:49 +02:00
FunctionScanState *node = castNode(FunctionScanState, pstate);
Re-implement EvalPlanQual processing to improve its performance and eliminate a lot of strange behaviors that occurred in join cases. We now identify the "current" row for every joined relation in UPDATE, DELETE, and SELECT FOR UPDATE/SHARE queries. If an EvalPlanQual recheck is necessary, we jam the appropriate row into each scan node in the rechecking plan, forcing it to emit only that one row. The former behavior could rescan the whole of each joined relation for each recheck, which was terrible for performance, and what's much worse could result in duplicated output tuples. Also, the original implementation of EvalPlanQual could not re-use the recheck execution tree --- it had to go through a full executor init and shutdown for every row to be tested. To avoid this overhead, I've associated a special runtime Param with each LockRows or ModifyTable plan node, and arranged to make every scan node below such a node depend on that Param. Thus, by signaling a change in that Param, the EPQ machinery can just rescan the already-built test plan. This patch also adds a prohibition on set-returning functions in the targetlist of SELECT FOR UPDATE/SHARE. This is needed to avoid the duplicate-output-tuple problem. It seems fairly reasonable since the other restrictions on SELECT FOR UPDATE are meant to ensure that there is a unique correspondence between source tuples and result tuples, which an output SRF destroys as much as anything else does.
2009-10-26 03:26:45 +01:00
return ExecScan(&node->ss,
(ExecScanAccessMtd) FunctionNext,
(ExecScanRecheckMtd) FunctionRecheck);
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
}
/* ----------------------------------------------------------------
* ExecInitFunctionScan
* ----------------------------------------------------------------
*/
Phase 1 of read-only-plans project: cause executor state nodes to point to plan nodes, not vice-versa. All executor state nodes now inherit from struct PlanState. Copying of plan trees has been simplified by not storing a list of SubPlans in Plan nodes (eliminating duplicate links). The executor still needs such a list, but it can build it during ExecutorStart since it has to scan the plan tree anyway. No initdb forced since no stored-on-disk structures changed, but you will need a full recompile because of node-numbering changes.
2002-12-05 16:50:39 +01:00
FunctionScanState *
Extend the ExecInitNode API so that plan nodes receive a set of flag bits indicating which optional capabilities can actually be exercised at runtime. This will allow Sort and Material nodes, and perhaps later other nodes, to avoid unnecessary overhead in common cases. This commit just adds the infrastructure and arranges to pass the correct flag values down to plan nodes; none of the actual optimizations are here yet. I'm committing this separately in case anyone wants to measure the added overhead. (It should be negligible.) Simon Riggs and Tom Lane
2006-02-28 05:10:28 +01:00
ExecInitFunctionScan(FunctionScan *node, EState *estate, int eflags)
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
{
pgindent run.
2002-09-04 22:31:48 +02:00
FunctionScanState *scanstate;
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
int nfuncs = list_length(node->functions);
TupleDesc scan_tupdesc;
int i,
natts;
ListCell *lc;
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
Improve tuplestore.c to support multiple concurrent read positions. This facility replaces the former mark/restore support but is otherwise upward-compatible with previous uses. It's expected to be needed for single evaluation of CTEs and also for window functions, so I'm committing it separately instead of waiting for either one of those patches to be finished. Per discussion with Greg Stark and Hitoshi Harada. Note: I removed nodeFunctionscan's mark/restore support, instead of bothering to update it for this change, because it was dead code anyway.
2008-10-01 21:51:50 +02:00
/* check for unsupported flags */
Assert(!(eflags & EXEC_FLAG_MARK));
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
/*
* FunctionScan should not have any children.
*/
Phase 1 of read-only-plans project: cause executor state nodes to point to plan nodes, not vice-versa. All executor state nodes now inherit from struct PlanState. Copying of plan trees has been simplified by not storing a list of SubPlans in Plan nodes (eliminating duplicate links). The executor still needs such a list, but it can build it during ExecutorStart since it has to scan the plan tree anyway. No initdb forced since no stored-on-disk structures changed, but you will need a full recompile because of node-numbering changes.
2002-12-05 16:50:39 +01:00
Assert(outerPlan(node) == NULL);
Assert(innerPlan(node) == NULL);
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
/*
* create new ScanState for node
*/
scanstate = makeNode(FunctionScanState);
Phase 1 of read-only-plans project: cause executor state nodes to point to plan nodes, not vice-versa. All executor state nodes now inherit from struct PlanState. Copying of plan trees has been simplified by not storing a list of SubPlans in Plan nodes (eliminating duplicate links). The executor still needs such a list, but it can build it during ExecutorStart since it has to scan the plan tree anyway. No initdb forced since no stored-on-disk structures changed, but you will need a full recompile because of node-numbering changes.
2002-12-05 16:50:39 +01:00
scanstate->ss.ps.plan = (Plan *) node;
scanstate->ss.ps.state = estate;
Move ExecProcNode from dispatch to function pointer based model. This allows us to add stack-depth checks the first time an executor node is called, and skip that overhead on following calls. Additionally it yields a nice speedup. While it'd probably have been a good idea to have that check all along, it has become more important after the new expression evaluation framework in b8d7f053c5c2bf2a7e - there's no stack depth check in common paths anymore now. We previously relied on ExecEvalExpr() being executed somewhere. We should move towards that model for further routines, but as this is required for v10, it seems better to only do the necessary (which already is quite large). Author: Andres Freund, Tom Lane Reported-By: Julien Rouhaud Discussion: https://postgr.es/m/22833.1490390175@sss.pgh.pa.us https://postgr.es/m/b0af9eaa-130c-60d0-9e4e-7a135b1e0c76@dalibo.com
2017-07-17 09:33:49 +02:00
scanstate->ss.ps.ExecProcNode = ExecFunctionScan;
Be more tense about not creating tuplestores with randomAccess = true unless backwards scan could actually happen. In particular, pass a flag to materialize-mode SRFs that tells them whether they need to require random access. In passing, also suppress unneeded backward-scan overhead for a Portal's holdStore tuplestore. Per my proposal about reducing I/O costs for tuplestores.
2008-10-29 01:00:39 +01:00
scanstate->eflags = eflags;
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
/*
* are we adding an ordinality column?
*/
scanstate->ordinality = node->funcordinality;
scanstate->nfuncs = nfuncs;
if (nfuncs == 1 && !node->funcordinality)
scanstate->simple = true;
else
scanstate->simple = false;
/*
* Ordinal 0 represents the "before the first row" position.
*
* We need to track ordinal position even when not adding an ordinality
* column to the result, in order to handle backwards scanning properly
* with multiple functions with different result sizes. (We can't position
* any individual function's tuplestore any more than 1 place beyond its
* end, so when scanning backwards, we need to know when to start
* including the function in the scan again.)
*/
scanstate->ordinal = 0;
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
/*
* Miscellaneous initialization
*
* create expression context for node
*/
Phase 1 of read-only-plans project: cause executor state nodes to point to plan nodes, not vice-versa. All executor state nodes now inherit from struct PlanState. Copying of plan trees has been simplified by not storing a list of SubPlans in Plan nodes (eliminating duplicate links). The executor still needs such a list, but it can build it during ExecutorStart since it has to scan the plan tree anyway. No initdb forced since no stored-on-disk structures changed, but you will need a full recompile because of node-numbering changes.
2002-12-05 16:50:39 +01:00
ExecAssignExprContext(estate, &scanstate->ss.ps);
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
/*
* tuple table initialization
*/
Phase 1 of read-only-plans project: cause executor state nodes to point to plan nodes, not vice-versa. All executor state nodes now inherit from struct PlanState. Copying of plan trees has been simplified by not storing a list of SubPlans in Plan nodes (eliminating duplicate links). The executor still needs such a list, but it can build it during ExecutorStart since it has to scan the plan tree anyway. No initdb forced since no stored-on-disk structures changed, but you will need a full recompile because of node-numbering changes.
2002-12-05 16:50:39 +01:00
ExecInitResultTupleSlot(estate, &scanstate->ss.ps);
ExecInitScanTupleSlot(estate, &scanstate->ss);
/*
* initialize child expressions
*/
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
scanstate->ss.ps.qual =
ExecInitQual(node->scan.plan.qual, (PlanState *) scanstate);
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
scanstate->funcstates = palloc(nfuncs * sizeof(FunctionScanPerFuncState));
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
natts = 0;
i = 0;
foreach(lc, node->functions)
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
{
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
RangeTblFunction *rtfunc = (RangeTblFunction *) lfirst(lc);
Node *funcexpr = rtfunc->funcexpr;
int colcount = rtfunc->funccolcount;
FunctionScanPerFuncState *fs = &scanstate->funcstates[i];
TypeFuncClass functypclass;
Oid funcrettype;
TupleDesc tupdesc;
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
fs->setexpr =
ExecInitTableFunctionResult((Expr *) funcexpr,
scanstate->ss.ps.ps_ExprContext,
&scanstate->ss.ps);
Add SQL Standard WITH ORDINALITY support for UNNEST (and any other SRF) Author: Andrew Gierth, David Fetter Reviewers: Dean Rasheed, Jeevan Chalke, Stephen Frost
2013-07-29 17:38:01 +02:00
/*
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
* Don't allocate the tuplestores; the actual calls to the functions
* do that. NULL means that we have not called the function yet (or
* need to call it again after a rescan).
Add SQL Standard WITH ORDINALITY support for UNNEST (and any other SRF) Author: Andrew Gierth, David Fetter Reviewers: Dean Rasheed, Jeevan Chalke, Stephen Frost
2013-07-29 17:38:01 +02:00
*/
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
fs->tstore = NULL;
fs->rowcount = -1;
Add SQL Standard WITH ORDINALITY support for UNNEST (and any other SRF) Author: Andrew Gierth, David Fetter Reviewers: Dean Rasheed, Jeevan Chalke, Stephen Frost
2013-07-29 17:38:01 +02:00
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
/*
* Now determine if the function returns a simple or composite type,
* and build an appropriate tupdesc. Note that in the composite case,
* the function may now return more columns than it did when the plan
* was made; we have to ignore any columns beyond "colcount".
*/
functypclass = get_expr_result_type(funcexpr,
&funcrettype,
&tupdesc);
Attached are two patches to implement and document anonymous composite types for Table Functions, as previously proposed on HACKERS. Here is a brief explanation: 1. Creates a new pg_type typtype: 'p' for pseudo type (currently either 'b' for base or 'c' for catalog, i.e. a class). 2. Creates new builtin type of typtype='p' named RECORD. This is the first of potentially several pseudo types. 3. Modify FROM clause grammer to accept: SELECT * FROM my_func() AS m(colname1 type1, colname2 type1, ...) where m is the table alias, colname1, etc are the column names, and type1, etc are the column types. 4. When typtype == 'p' and the function return type is RECORD, a list of column defs is required, and when typtype != 'p', it is disallowed. 5. A check was added to ensure that the tupdesc provide via the parser and the actual return tupdesc match in number and type of attributes. When creating a function you can do: CREATE FUNCTION foo(text) RETURNS setof RECORD ... When using it you can do: SELECT * from foo(sqlstmt) AS (f1 int, f2 text, f3 timestamp) or SELECT * from foo(sqlstmt) AS f(f1 int, f2 text, f3 timestamp) or SELECT * from foo(sqlstmt) f(f1 int, f2 text, f3 timestamp) Included in the patches are adjustments to the regression test sql and expected files, and documentation. p.s. This potentially solves (or at least improves) the issue of builtin Table Functions. They can be bootstrapped as returning RECORD, and we can wrap system views around them with properly specified column defs. For example: CREATE VIEW pg_settings AS SELECT s.name, s.setting FROM show_all_settings()AS s(name text, setting text); Then we can also add the UPDATE RULE that I previously posted to pg_settings, and have pg_settings act like a virtual table, allowing settings to be queried and set. Joe Conway
2002-08-04 21:48:11 +02:00
Support domains over composite types. This is the last major omission in our domains feature: you can now make a domain over anything that's not a pseudotype. The major complication from an implementation standpoint is that places that might be creating tuples of a domain type now need to be prepared to apply domain_check(). It seems better that unprepared code fail with an error like "<type> is not composite" than that it silently fail to apply domain constraints. Therefore, relevant infrastructure like get_func_result_type() and lookup_rowtype_tupdesc() has been adjusted to treat domain-over-composite as a distinct case that unprepared code won't recognize, rather than just transparently treating it the same as plain composite. This isn't a 100% solution to the possibility of overlooked domain checks, but it catches most places. In passing, improve typcache.c's support for domains (it can now cache the identity of a domain's base type), and rewrite the argument handling logic in jsonfuncs.c's populate_record[set]_worker to reduce duplicative per-call lookups. I believe this is code-complete so far as the core and contrib code go. The PLs need varying amounts of work, which will be tackled in followup patches. Discussion: https://postgr.es/m/4206.1499798337@sss.pgh.pa.us
2017-10-26 19:47:45 +02:00
if (functypclass == TYPEFUNC_COMPOSITE ||
functypclass == TYPEFUNC_COMPOSITE_DOMAIN)
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
{
/* Composite data type, e.g. a table's row type */
Assert(tupdesc);
Assert(tupdesc->natts >= colcount);
/* Must copy it out of typcache for safety */
tupdesc = CreateTupleDescCopy(tupdesc);
}
else if (functypclass == TYPEFUNC_SCALAR)
{
/* Base data type, i.e. scalar */
tupdesc = CreateTemplateTupleDesc(1, false);
TupleDescInitEntry(tupdesc,
(AttrNumber) 1,
NULL, /* don't care about the name here */
funcrettype,
-1,
0);
TupleDescInitEntryCollation(tupdesc,
(AttrNumber) 1,
exprCollation(funcexpr));
}
else if (functypclass == TYPEFUNC_RECORD)
{
tupdesc = BuildDescFromLists(rtfunc->funccolnames,
rtfunc->funccoltypes,
rtfunc->funccoltypmods,
rtfunc->funccolcollations);
/*
* For RECORD results, make sure a typmod has been assigned. (The
* function should do this for itself, but let's cover things in
* case it doesn't.)
*/
BlessTupleDesc(tupdesc);
}
else
{
/* crummy error message, but parser should have caught this */
elog(ERROR, "function in FROM has unsupported return type");
}
fs->tupdesc = tupdesc;
fs->colcount = colcount;
/*
* We only need separate slots for the function results if we are
* doing ordinality or multiple functions; otherwise, we'll fetch
* function results directly into the scan slot.
*/
if (!scanstate->simple)
{
fs->func_slot = ExecInitExtraTupleSlot(estate);
ExecSetSlotDescriptor(fs->func_slot, fs->tupdesc);
}
else
fs->func_slot = NULL;
natts += colcount;
i++;
}
Add SQL Standard WITH ORDINALITY support for UNNEST (and any other SRF) Author: Andrew Gierth, David Fetter Reviewers: Dean Rasheed, Jeevan Chalke, Stephen Frost
2013-07-29 17:38:01 +02:00
/*
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
* Create the combined TupleDesc
Add SQL Standard WITH ORDINALITY support for UNNEST (and any other SRF) Author: Andrew Gierth, David Fetter Reviewers: Dean Rasheed, Jeevan Chalke, Stephen Frost
2013-07-29 17:38:01 +02:00
*
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
* If there is just one function without ordinality, the scan result
pgindent run for 9.4 This includes removing tabs after periods in C comments, which was applied to back branches, so this change should not effect backpatching.
2014-05-06 18:12:18 +02:00
* tupdesc is the same as the function result tupdesc --- except that we
* may stuff new names into it below, so drop any rowtype label.
Add SQL Standard WITH ORDINALITY support for UNNEST (and any other SRF) Author: Andrew Gierth, David Fetter Reviewers: Dean Rasheed, Jeevan Chalke, Stephen Frost
2013-07-29 17:38:01 +02:00
*/
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
if (scanstate->simple)
Add SQL Standard WITH ORDINALITY support for UNNEST (and any other SRF) Author: Andrew Gierth, David Fetter Reviewers: Dean Rasheed, Jeevan Chalke, Stephen Frost
2013-07-29 17:38:01 +02:00
{
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
scan_tupdesc = CreateTupleDescCopy(scanstate->funcstates[0].tupdesc);
scan_tupdesc->tdtypeid = RECORDOID;
scan_tupdesc->tdtypmod = -1;
}
else
{
AttrNumber attno = 0;
Add SQL Standard WITH ORDINALITY support for UNNEST (and any other SRF) Author: Andrew Gierth, David Fetter Reviewers: Dean Rasheed, Jeevan Chalke, Stephen Frost
2013-07-29 17:38:01 +02:00
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
if (node->funcordinality)
natts++;
Put back blessing of record-function tupledesc, which I removed in a fit of over-optimization.
2005-04-15 00:09:40 +02:00
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
scan_tupdesc = CreateTemplateTupleDesc(natts, false);
Add SQL Standard WITH ORDINALITY support for UNNEST (and any other SRF) Author: Andrew Gierth, David Fetter Reviewers: Dean Rasheed, Jeevan Chalke, Stephen Frost
2013-07-29 17:38:01 +02:00
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
for (i = 0; i < nfuncs; i++)
{
TupleDesc tupdesc = scanstate->funcstates[i].tupdesc;
int colcount = scanstate->funcstates[i].colcount;
int j;
Add SQL Standard WITH ORDINALITY support for UNNEST (and any other SRF) Author: Andrew Gierth, David Fetter Reviewers: Dean Rasheed, Jeevan Chalke, Stephen Frost
2013-07-29 17:38:01 +02:00
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
for (j = 1; j <= colcount; j++)
TupleDescCopyEntry(scan_tupdesc, ++attno, tupdesc, j);
}
/* If doing ordinality, add a column of type "bigint" at the end */
if (node->funcordinality)
{
TupleDescInitEntry(scan_tupdesc,
++attno,
NULL, /* don't care about the name here */
INT8OID,
-1,
0);
}
Add SQL Standard WITH ORDINALITY support for UNNEST (and any other SRF) Author: Andrew Gierth, David Fetter Reviewers: Dean Rasheed, Jeevan Chalke, Stephen Frost
2013-07-29 17:38:01 +02:00
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
Assert(attno == natts);
}
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
ExecAssignScanType(&scanstate->ss, scan_tupdesc);
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
/*
Fix wrong/misleading comments, be more consistent about where to call ExecAssignResultTypeFromTL().
2003-01-12 23:01:38 +01:00
* Initialize result tuple type and projection info.
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
*/
Phase 1 of read-only-plans project: cause executor state nodes to point to plan nodes, not vice-versa. All executor state nodes now inherit from struct PlanState. Copying of plan trees has been simplified by not storing a list of SubPlans in Plan nodes (eliminating duplicate links). The executor still needs such a list, but it can build it during ExecutorStart since it has to scan the plan tree anyway. No initdb forced since no stored-on-disk structures changed, but you will need a full recompile because of node-numbering changes.
2002-12-05 16:50:39 +01:00
ExecAssignResultTypeFromTL(&scanstate->ss.ps);
Teach the planner to remove SubqueryScan nodes from the plan if they aren't doing anything useful (ie, neither selection nor projection). Also, extend to SubqueryScan the hacks already in place to avoid unnecessary ExecProject calls when the result would just be the same tuple the subquery already delivered. This saves some overhead in UNION and other set operations, as well as avoiding overhead for unflatten-able subqueries. Per example from Sokolov Yura.
2005-05-23 00:30:20 +02:00
ExecAssignScanProjectionInfo(&scanstate->ss);
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
Avoid leaking memory while evaluating arguments for a table function. ExecMakeTableFunctionResult evaluated the arguments for a function-in-FROM in the query-lifespan memory context. This is insignificant in simple cases where the function relation is scanned only once; but if the function is in a sub-SELECT or is on the inside of a nested loop, any memory consumed during argument evaluation can add up quickly. (The potential for trouble here had been foreseen long ago, per existing comments; but we'd not previously seen a complaint from the field about it.) To fix, create an additional temporary context just for this purpose. Per an example from MauMau. Back-patch to all active branches.
2014-06-20 04:13:41 +02:00
/*
* Create a memory context that ExecMakeTableFunctionResult can use to
* evaluate function arguments in. We can't use the per-tuple context for
* this because it gets reset too often; but we don't want to leak
* evaluation results into the query-lifespan context either. We just
* need one context, because we evaluate each function separately.
*/
scanstate->argcontext = AllocSetContextCreate(CurrentMemoryContext,
"Table function arguments",
Add macros to make AllocSetContextCreate() calls simpler and safer. I found that half a dozen (nearly 5%) of our AllocSetContextCreate calls had typos in the context-sizing parameters. While none of these led to especially significant problems, they did create minor inefficiencies, and it's now clear that expecting people to copy-and-paste those calls accurately is not a great idea. Let's reduce the risk of future errors by introducing single macros that encapsulate the common use-cases. Three such macros are enough to cover all but two special-purpose contexts; those two calls can be left as-is, I think. While this patch doesn't in itself improve matters for third-party extensions, it doesn't break anything for them either, and they can gradually adopt the simplified notation over time. In passing, change TopMemoryContext to use the default allocation parameters. Formerly it could only be extended 8K at a time. That was probably reasonable when this code was written; but nowadays we create many more contexts than we did then, so that it's not unusual to have a couple hundred K in TopMemoryContext, even without considering various dubious code that sticks other things there. There seems no good reason not to let it use growing blocks like most other contexts. Back-patch to 9.6, mostly because that's still close enough to HEAD that it's easy to do so, and keeping the branches in sync can be expected to avoid some future back-patching pain. The bugs fixed by these changes don't seem to be significant enough to justify fixing them further back. Discussion: <21072.1472321324@sss.pgh.pa.us>
2016-08-27 23:50:38 +02:00
ALLOCSET_DEFAULT_SIZES);
Avoid leaking memory while evaluating arguments for a table function. ExecMakeTableFunctionResult evaluated the arguments for a function-in-FROM in the query-lifespan memory context. This is insignificant in simple cases where the function relation is scanned only once; but if the function is in a sub-SELECT or is on the inside of a nested loop, any memory consumed during argument evaluation can add up quickly. (The potential for trouble here had been foreseen long ago, per existing comments; but we'd not previously seen a complaint from the field about it.) To fix, create an additional temporary context just for this purpose. Per an example from MauMau. Back-patch to all active branches.
2014-06-20 04:13:41 +02:00
Phase 1 of read-only-plans project: cause executor state nodes to point to plan nodes, not vice-versa. All executor state nodes now inherit from struct PlanState. Copying of plan trees has been simplified by not storing a list of SubPlans in Plan nodes (eliminating duplicate links). The executor still needs such a list, but it can build it during ExecutorStart since it has to scan the plan tree anyway. No initdb forced since no stored-on-disk structures changed, but you will need a full recompile because of node-numbering changes.
2002-12-05 16:50:39 +01:00
return scanstate;
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
}
/* ----------------------------------------------------------------
* ExecEndFunctionScan
*
* frees any storage allocated through C routines.
* ----------------------------------------------------------------
*/
void
Phase 1 of read-only-plans project: cause executor state nodes to point to plan nodes, not vice-versa. All executor state nodes now inherit from struct PlanState. Copying of plan trees has been simplified by not storing a list of SubPlans in Plan nodes (eliminating duplicate links). The executor still needs such a list, but it can build it during ExecutorStart since it has to scan the plan tree anyway. No initdb forced since no stored-on-disk structures changed, but you will need a full recompile because of node-numbering changes.
2002-12-05 16:50:39 +01:00
ExecEndFunctionScan(FunctionScanState *node)
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
{
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
int i;
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
/*
Revise executor APIs so that all per-query state structure is built in a per-query memory context created by CreateExecutorState --- and destroyed by FreeExecutorState. This provides a final solution to the longstanding problem of memory leaked by various ExecEndNode calls.
2002-12-15 17:17:59 +01:00
* Free the exprcontext
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
*/
Phase 1 of read-only-plans project: cause executor state nodes to point to plan nodes, not vice-versa. All executor state nodes now inherit from struct PlanState. Copying of plan trees has been simplified by not storing a list of SubPlans in Plan nodes (eliminating duplicate links). The executor still needs such a list, but it can build it during ExecutorStart since it has to scan the plan tree anyway. No initdb forced since no stored-on-disk structures changed, but you will need a full recompile because of node-numbering changes.
2002-12-05 16:50:39 +01:00
ExecFreeExprContext(&node->ss.ps);
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
/*
* clean out the tuple table
*/
Phase 1 of read-only-plans project: cause executor state nodes to point to plan nodes, not vice-versa. All executor state nodes now inherit from struct PlanState. Copying of plan trees has been simplified by not storing a list of SubPlans in Plan nodes (eliminating duplicate links). The executor still needs such a list, but it can build it during ExecutorStart since it has to scan the plan tree anyway. No initdb forced since no stored-on-disk structures changed, but you will need a full recompile because of node-numbering changes.
2002-12-05 16:50:39 +01:00
ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
ExecClearTuple(node->ss.ss_ScanTupleSlot);
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
/*
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
* Release slots and tuplestore resources
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
*/
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
for (i = 0; i < node->nfuncs; i++)
{
FunctionScanPerFuncState *fs = &node->funcstates[i];
if (fs->func_slot)
ExecClearTuple(fs->func_slot);
if (fs->tstore != NULL)
{
tuplestore_end(node->funcstates[i].tstore);
fs->tstore = NULL;
}
}
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
}
/* ----------------------------------------------------------------
Make NestLoop plan nodes pass outer-relation variables into their inner relation using the general PARAM_EXEC executor parameter mechanism, rather than the ad-hoc kluge of passing the outer tuple down through ExecReScan. The previous method was hard to understand and could never be extended to handle parameters coming from multiple join levels. This patch doesn't change the set of possible plans nor have any significant performance effect, but it's necessary infrastructure for future generalization of the concept of an inner indexscan plan. ExecReScan's second parameter is now unused, so it's removed.
2010-07-12 19:01:06 +02:00
* ExecReScanFunctionScan
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
*
* Rescans the relation.
* ----------------------------------------------------------------
*/
void
Make NestLoop plan nodes pass outer-relation variables into their inner relation using the general PARAM_EXEC executor parameter mechanism, rather than the ad-hoc kluge of passing the outer tuple down through ExecReScan. The previous method was hard to understand and could never be extended to handle parameters coming from multiple join levels. This patch doesn't change the set of possible plans nor have any significant performance effect, but it's necessary infrastructure for future generalization of the concept of an inner indexscan plan. ExecReScan's second parameter is now unused, so it's removed.
2010-07-12 19:01:06 +02:00
ExecReScanFunctionScan(FunctionScanState *node)
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
{
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
FunctionScan *scan = (FunctionScan *) node->ss.ps.plan;
int i;
Bitmapset *chgparam = node->ss.ps.chgParam;
Phase 1 of read-only-plans project: cause executor state nodes to point to plan nodes, not vice-versa. All executor state nodes now inherit from struct PlanState. Copying of plan trees has been simplified by not storing a list of SubPlans in Plan nodes (eliminating duplicate links). The executor still needs such a list, but it can build it during ExecutorStart since it has to scan the plan tree anyway. No initdb forced since no stored-on-disk structures changed, but you will need a full recompile because of node-numbering changes.
2002-12-05 16:50:39 +01:00
ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
for (i = 0; i < node->nfuncs; i++)
{
FunctionScanPerFuncState *fs = &node->funcstates[i];
Re-implement EvalPlanQual processing to improve its performance and eliminate a lot of strange behaviors that occurred in join cases. We now identify the "current" row for every joined relation in UPDATE, DELETE, and SELECT FOR UPDATE/SHARE queries. If an EvalPlanQual recheck is necessary, we jam the appropriate row into each scan node in the rechecking plan, forcing it to emit only that one row. The former behavior could rescan the whole of each joined relation for each recheck, which was terrible for performance, and what's much worse could result in duplicated output tuples. Also, the original implementation of EvalPlanQual could not re-use the recheck execution tree --- it had to go through a full executor init and shutdown for every row to be tested. To avoid this overhead, I've associated a special runtime Param with each LockRows or ModifyTable plan node, and arranged to make every scan node below such a node depend on that Param. Thus, by signaling a change in that Param, the EPQ machinery can just rescan the already-built test plan. This patch also adds a prohibition on set-returning functions in the targetlist of SELECT FOR UPDATE/SHARE. This is needed to avoid the duplicate-output-tuple problem. It seems fairly reasonable since the other restrictions on SELECT FOR UPDATE are meant to ensure that there is a unique correspondence between source tuples and result tuples, which an output SRF destroys as much as anything else does.
2009-10-26 03:26:45 +01:00
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
if (fs->func_slot)
ExecClearTuple(fs->func_slot);
}
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
ExecScanReScan(&node->ss);
Add SQL Standard WITH ORDINALITY support for UNNEST (and any other SRF) Author: Andrew Gierth, David Fetter Reviewers: Dean Rasheed, Jeevan Chalke, Stephen Frost
2013-07-29 17:38:01 +02:00
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
/*
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
* Here we have a choice whether to drop the tuplestores (and recompute
* the function outputs) or just rescan them. We must recompute if an
* expression contains changed parameters, else we rescan.
*
* XXX maybe we should recompute if the function is volatile? But in
* general the executor doesn't conditionalize its actions on that.
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
*/
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
if (chgparam)
{
ListCell *lc;
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
i = 0;
foreach(lc, scan->functions)
{
RangeTblFunction *rtfunc = (RangeTblFunction *) lfirst(lc);
if (bms_overlap(chgparam, rtfunc->funcparams))
{
if (node->funcstates[i].tstore != NULL)
{
tuplestore_end(node->funcstates[i].tstore);
node->funcstates[i].tstore = NULL;
}
node->funcstates[i].rowcount = -1;
}
i++;
}
}
/* Reset ordinality counter */
node->ordinal = 0;
/* Make sure we rewind any remaining tuplestores */
for (i = 0; i < node->nfuncs; i++)
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
{
Support multi-argument UNNEST(), and TABLE() syntax for multiple functions. This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
2013-11-22 01:37:02 +01:00
if (node->funcstates[i].tstore != NULL)
tuplestore_rescan(node->funcstates[i].tstore);
First pass at set-returning-functions in FROM, by Joe Conway with some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
2002-05-12 22:10:05 +02:00
}
}