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postgresql/src/backend/executor/nodeModifyTable.c

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Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
/*-------------------------------------------------------------------------
*
* nodeModifyTable.c
* routines to handle ModifyTable nodes.
*
Update copyrights for 2013 Fully update git head, and update back branches in ./COPYRIGHT and legal.sgml files.
2013-01-01 23:15:01 +01:00
* Portions Copyright (c) 1996-2013, PostgreSQL Global Development Group
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +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/nodeModifyTable.c
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
*
*-------------------------------------------------------------------------
*/
/* INTERFACE ROUTINES
pgindent run for 9.0
2010-02-26 03:01:40 +01:00
* ExecInitModifyTable - initialize the ModifyTable node
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
* ExecModifyTable - retrieve the next tuple from the node
* ExecEndModifyTable - shut down the ModifyTable node
* ExecReScanModifyTable - rescan the ModifyTable node
*
* NOTES
* Each ModifyTable node contains a list of one or more subplans,
* much like an Append node. There is one subplan per result relation.
* The key reason for this is that in an inherited UPDATE command, each
* result relation could have a different schema (more or different
* columns) requiring a different plan tree to produce it. In an
* inherited DELETE, all the subplans should produce the same output
* rowtype, but we might still find that different plans are appropriate
* for different child relations.
*
* If the query specifies RETURNING, then the ModifyTable returns a
* RETURNING tuple after completing each row insert, update, or delete.
pgindent run for 9.0
2010-02-26 03:01:40 +01:00
* It must be called again to continue the operation. Without RETURNING,
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
* we just loop within the node until all the work is done, then
* return NULL. This avoids useless call/return overhead.
*/
#include "postgres.h"
Split tuple struct defs from htup.h to htup_details.h This reduces unnecessary exposure of other headers through htup.h, which is very widely included by many files. I have chosen to move the function prototypes to the new file as well, because that means htup.h no longer needs to include tupdesc.h. In itself this doesn't have much effect in indirect inclusion of tupdesc.h throughout the tree, because it's also required by execnodes.h; but it's something to explore in the future, and it seemed best to do the htup.h change now while I'm busy with it.
2012-08-30 22:15:44 +02:00
#include "access/htup_details.h"
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
#include "access/xact.h"
#include "commands/trigger.h"
#include "executor/executor.h"
#include "executor/nodeModifyTable.h"
#include "miscadmin.h"
#include "nodes/nodeFuncs.h"
#include "storage/bufmgr.h"
#include "utils/builtins.h"
#include "utils/memutils.h"
Move Trigger and TriggerDesc structs out of rel.h into a new reltrigger.h This lets us stop including rel.h into execnodes.h, which is a widely used header.
2011-02-23 18:18:09 +01:00
#include "utils/rel.h"
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
#include "utils/tqual.h"
/*
* Verify that the tuples to be produced by INSERT or UPDATE match the
* target relation's rowtype
*
* We do this to guard against stale plans. If plan invalidation is
* functioning properly then we should never get a failure here, but better
* safe than sorry. Note that this is called after we have obtained lock
* on the target rel, so the rowtype can't change underneath us.
*
* The plan output is represented by its targetlist, because that makes
* handling the dropped-column case easier.
*/
static void
ExecCheckPlanOutput(Relation resultRel, List *targetList)
{
TupleDesc resultDesc = RelationGetDescr(resultRel);
int attno = 0;
ListCell *lc;
foreach(lc, targetList)
{
TargetEntry *tle = (TargetEntry *) lfirst(lc);
Form_pg_attribute attr;
if (tle->resjunk)
continue; /* ignore junk tlist items */
if (attno >= resultDesc->natts)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("table row type and query-specified row type do not match"),
errdetail("Query has too many columns.")));
attr = resultDesc->attrs[attno++];
if (!attr->attisdropped)
{
/* Normal case: demand type match */
if (exprType((Node *) tle->expr) != attr->atttypid)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("table row type and query-specified row type do not match"),
errdetail("Table has type %s at ordinal position %d, but query expects %s.",
format_type_be(attr->atttypid),
attno,
format_type_be(exprType((Node *) tle->expr)))));
}
else
{
/*
* For a dropped column, we can't check atttypid (it's likely 0).
* In any case the planner has most likely inserted an INT4 null.
* What we insist on is just *some* NULL constant.
*/
if (!IsA(tle->expr, Const) ||
!((Const *) tle->expr)->constisnull)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("table row type and query-specified row type do not match"),
errdetail("Query provides a value for a dropped column at ordinal position %d.",
attno)));
}
}
if (attno != resultDesc->natts)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("table row type and query-specified row type do not match"),
errdetail("Query has too few columns.")));
}
/*
* ExecProcessReturning --- evaluate a RETURNING list
*
* projectReturning: RETURNING projection info for current result rel
* tupleSlot: slot holding tuple actually inserted/updated/deleted
* planSlot: slot holding tuple returned by top subplan node
*
* Returns a slot holding the result tuple
*/
static TupleTableSlot *
ExecProcessReturning(ProjectionInfo *projectReturning,
TupleTableSlot *tupleSlot,
TupleTableSlot *planSlot)
{
ExprContext *econtext = projectReturning->pi_exprContext;
/*
* Reset per-tuple memory context to free any expression evaluation
* storage allocated in the previous cycle.
*/
ResetExprContext(econtext);
/* Make tuple and any needed join variables available to ExecProject */
econtext->ecxt_scantuple = tupleSlot;
econtext->ecxt_outertuple = planSlot;
/* Compute the RETURNING expressions */
return ExecProject(projectReturning, NULL);
}
/* ----------------------------------------------------------------
* ExecInsert
*
* For INSERT, we have to insert the tuple into the target relation
* and insert appropriate tuples into the index relations.
*
* Returns RETURNING result if any, otherwise NULL.
* ----------------------------------------------------------------
*/
static TupleTableSlot *
ExecInsert(TupleTableSlot *slot,
TupleTableSlot *planSlot,
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
EState *estate,
bool canSetTag)
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
{
HeapTuple tuple;
ResultRelInfo *resultRelInfo;
Relation resultRelationDesc;
Oid newId;
List *recheckIndexes = NIL;
/*
* get the heap tuple out of the tuple table slot, making sure we have a
* writable copy
*/
tuple = ExecMaterializeSlot(slot);
/*
* get information on the (current) result relation
*/
resultRelInfo = estate->es_result_relation_info;
resultRelationDesc = resultRelInfo->ri_RelationDesc;
/*
* If the result relation has OIDs, force the tuple's OID to zero so that
* heap_insert will assign a fresh OID. Usually the OID already will be
* zero at this point, but there are corner cases where the plan tree can
* return a tuple extracted literally from some table with the same
* rowtype.
*
* XXX if we ever wanted to allow users to assign their own OIDs to new
* rows, this'd be the place to do it. For the moment, we make a point of
* doing this before calling triggers, so that a user-supplied trigger
* could hack the OID if desired.
*/
if (resultRelationDesc->rd_rel->relhasoids)
HeapTupleSetOid(tuple, InvalidOid);
/* BEFORE ROW INSERT Triggers */
if (resultRelInfo->ri_TrigDesc &&
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
resultRelInfo->ri_TrigDesc->trig_insert_before_row)
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
{
Fix dangling-pointer problem in before-row update trigger processing. ExecUpdate checked for whether ExecBRUpdateTriggers had returned a new tuple value by seeing if the returned tuple was pointer-equal to the old one. But the "old one" was in estate->es_junkFilter's result slot, which would be scribbled on if we had done an EvalPlanQual update in response to a concurrent update of the target tuple; therefore we were comparing a dangling pointer to a live one. Given the right set of circumstances we could get a false match, resulting in not forcing the tuple to be stored in the slot we thought it was stored in. In the case reported by Maxim Boguk in bug #5798, this led to "cannot extract system attribute from virtual tuple" failures when trying to do "RETURNING ctid". I believe there is a very-low-probability chance of more serious errors, such as generating incorrect index entries based on the original rather than the trigger-modified version of the row. In HEAD, change all of ExecBRInsertTriggers, ExecIRInsertTriggers, ExecBRUpdateTriggers, and ExecIRUpdateTriggers so that they continue to have similar APIs. In the back branches I just changed ExecBRUpdateTriggers, since there is no bug in the ExecBRInsertTriggers case.
2011-02-22 03:18:04 +01:00
slot = ExecBRInsertTriggers(estate, resultRelInfo, slot);
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
Fix dangling-pointer problem in before-row update trigger processing. ExecUpdate checked for whether ExecBRUpdateTriggers had returned a new tuple value by seeing if the returned tuple was pointer-equal to the old one. But the "old one" was in estate->es_junkFilter's result slot, which would be scribbled on if we had done an EvalPlanQual update in response to a concurrent update of the target tuple; therefore we were comparing a dangling pointer to a live one. Given the right set of circumstances we could get a false match, resulting in not forcing the tuple to be stored in the slot we thought it was stored in. In the case reported by Maxim Boguk in bug #5798, this led to "cannot extract system attribute from virtual tuple" failures when trying to do "RETURNING ctid". I believe there is a very-low-probability chance of more serious errors, such as generating incorrect index entries based on the original rather than the trigger-modified version of the row. In HEAD, change all of ExecBRInsertTriggers, ExecIRInsertTriggers, ExecBRUpdateTriggers, and ExecIRUpdateTriggers so that they continue to have similar APIs. In the back branches I just changed ExecBRUpdateTriggers, since there is no bug in the ExecBRInsertTriggers case.
2011-02-22 03:18:04 +01:00
if (slot == NULL) /* "do nothing" */
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
return NULL;
Fix dangling-pointer problem in before-row update trigger processing. ExecUpdate checked for whether ExecBRUpdateTriggers had returned a new tuple value by seeing if the returned tuple was pointer-equal to the old one. But the "old one" was in estate->es_junkFilter's result slot, which would be scribbled on if we had done an EvalPlanQual update in response to a concurrent update of the target tuple; therefore we were comparing a dangling pointer to a live one. Given the right set of circumstances we could get a false match, resulting in not forcing the tuple to be stored in the slot we thought it was stored in. In the case reported by Maxim Boguk in bug #5798, this led to "cannot extract system attribute from virtual tuple" failures when trying to do "RETURNING ctid". I believe there is a very-low-probability chance of more serious errors, such as generating incorrect index entries based on the original rather than the trigger-modified version of the row. In HEAD, change all of ExecBRInsertTriggers, ExecIRInsertTriggers, ExecBRUpdateTriggers, and ExecIRUpdateTriggers so that they continue to have similar APIs. In the back branches I just changed ExecBRUpdateTriggers, since there is no bug in the ExecBRInsertTriggers case.
2011-02-22 03:18:04 +01:00
/* trigger might have changed tuple */
tuple = ExecMaterializeSlot(slot);
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
}
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
/* INSTEAD OF ROW INSERT Triggers */
if (resultRelInfo->ri_TrigDesc &&
resultRelInfo->ri_TrigDesc->trig_insert_instead_row)
{
Fix dangling-pointer problem in before-row update trigger processing. ExecUpdate checked for whether ExecBRUpdateTriggers had returned a new tuple value by seeing if the returned tuple was pointer-equal to the old one. But the "old one" was in estate->es_junkFilter's result slot, which would be scribbled on if we had done an EvalPlanQual update in response to a concurrent update of the target tuple; therefore we were comparing a dangling pointer to a live one. Given the right set of circumstances we could get a false match, resulting in not forcing the tuple to be stored in the slot we thought it was stored in. In the case reported by Maxim Boguk in bug #5798, this led to "cannot extract system attribute from virtual tuple" failures when trying to do "RETURNING ctid". I believe there is a very-low-probability chance of more serious errors, such as generating incorrect index entries based on the original rather than the trigger-modified version of the row. In HEAD, change all of ExecBRInsertTriggers, ExecIRInsertTriggers, ExecBRUpdateTriggers, and ExecIRUpdateTriggers so that they continue to have similar APIs. In the back branches I just changed ExecBRUpdateTriggers, since there is no bug in the ExecBRInsertTriggers case.
2011-02-22 03:18:04 +01:00
slot = ExecIRInsertTriggers(estate, resultRelInfo, slot);
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
Fix dangling-pointer problem in before-row update trigger processing. ExecUpdate checked for whether ExecBRUpdateTriggers had returned a new tuple value by seeing if the returned tuple was pointer-equal to the old one. But the "old one" was in estate->es_junkFilter's result slot, which would be scribbled on if we had done an EvalPlanQual update in response to a concurrent update of the target tuple; therefore we were comparing a dangling pointer to a live one. Given the right set of circumstances we could get a false match, resulting in not forcing the tuple to be stored in the slot we thought it was stored in. In the case reported by Maxim Boguk in bug #5798, this led to "cannot extract system attribute from virtual tuple" failures when trying to do "RETURNING ctid". I believe there is a very-low-probability chance of more serious errors, such as generating incorrect index entries based on the original rather than the trigger-modified version of the row. In HEAD, change all of ExecBRInsertTriggers, ExecIRInsertTriggers, ExecBRUpdateTriggers, and ExecIRUpdateTriggers so that they continue to have similar APIs. In the back branches I just changed ExecBRUpdateTriggers, since there is no bug in the ExecBRInsertTriggers case.
2011-02-22 03:18:04 +01:00
if (slot == NULL) /* "do nothing" */
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
return NULL;
Fix dangling-pointer problem in before-row update trigger processing. ExecUpdate checked for whether ExecBRUpdateTriggers had returned a new tuple value by seeing if the returned tuple was pointer-equal to the old one. But the "old one" was in estate->es_junkFilter's result slot, which would be scribbled on if we had done an EvalPlanQual update in response to a concurrent update of the target tuple; therefore we were comparing a dangling pointer to a live one. Given the right set of circumstances we could get a false match, resulting in not forcing the tuple to be stored in the slot we thought it was stored in. In the case reported by Maxim Boguk in bug #5798, this led to "cannot extract system attribute from virtual tuple" failures when trying to do "RETURNING ctid". I believe there is a very-low-probability chance of more serious errors, such as generating incorrect index entries based on the original rather than the trigger-modified version of the row. In HEAD, change all of ExecBRInsertTriggers, ExecIRInsertTriggers, ExecBRUpdateTriggers, and ExecIRUpdateTriggers so that they continue to have similar APIs. In the back branches I just changed ExecBRUpdateTriggers, since there is no bug in the ExecBRInsertTriggers case.
2011-02-22 03:18:04 +01:00
/* trigger might have changed tuple */
tuple = ExecMaterializeSlot(slot);
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
newId = InvalidOid;
}
else
{
/*
* Check the constraints of the tuple
*/
if (resultRelationDesc->rd_att->constr)
ExecConstraints(resultRelInfo, slot, estate);
/*
* insert the tuple
*
* Note: heap_insert returns the tid (location) of the new tuple in
* the t_self field.
*/
newId = heap_insert(resultRelationDesc, tuple,
estate->es_output_cid, 0, NULL);
/*
* insert index entries for tuple
*/
if (resultRelInfo->ri_NumIndices > 0)
recheckIndexes = ExecInsertIndexTuples(slot, &(tuple->t_self),
estate);
}
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
if (canSetTag)
{
(estate->es_processed)++;
estate->es_lastoid = newId;
setLastTid(&(tuple->t_self));
}
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
/* AFTER ROW INSERT Triggers */
ExecARInsertTriggers(estate, resultRelInfo, tuple, recheckIndexes);
Fix memory leak created by deferrable-index-constraints patches. We need to free the OID list returned by ExecInsertIndexTuples to avoid a query-lifespan memory leak. When many rows require rechecking, this can be a significant leak --- it's even more than the space used for the queued trigger events. Dean Rasheed
2010-01-31 19:15:39 +01:00
list_free(recheckIndexes);
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
/* Process RETURNING if present */
if (resultRelInfo->ri_projectReturning)
return ExecProcessReturning(resultRelInfo->ri_projectReturning,
slot, planSlot);
return NULL;
}
/* ----------------------------------------------------------------
* ExecDelete
*
* DELETE is like UPDATE, except that we delete the tuple and no
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
* index modifications are needed.
*
* When deleting from a table, tupleid identifies the tuple to
* delete and oldtuple is NULL. When deleting from a view,
* oldtuple is passed to the INSTEAD OF triggers and identifies
* what to delete, and tupleid is invalid.
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
*
* Returns RETURNING result if any, otherwise NULL.
* ----------------------------------------------------------------
*/
static TupleTableSlot *
ExecDelete(ItemPointer tupleid,
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
HeapTupleHeader oldtuple,
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
TupleTableSlot *planSlot,
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
EPQState *epqstate,
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
EState *estate,
bool canSetTag)
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
{
ResultRelInfo *resultRelInfo;
Relation resultRelationDesc;
HTSU_Result result;
Throw error if expiring tuple is again updated or deleted. This prevents surprising behavior when a FOR EACH ROW trigger BEFORE UPDATE or BEFORE DELETE directly or indirectly updates or deletes the the old row. Prior to this patch the requested action on the row could be silently ignored while all triggered actions based on the occurence of the requested action could be committed. One example of how this could happen is if the BEFORE DELETE trigger for a "parent" row deleted "children" which had trigger functions to update summary or status data on the parent. This also prevents similar surprising problems if the query has a volatile function which updates a target row while it is already being updated. There are related issues present in FOR UPDATE cursors and READ COMMITTED queries which are not handled by this patch. These issues need further evalution to determine what change, if any, is needed. Where the new error messages are generated, in most cases the best fix will be to move code from the BEFORE trigger to an AFTER trigger. Where this is not feasible, the trigger can avoid the error by re-issuing the triggering statement and returning NULL. Documentation changes will be submitted in a separate patch. Kevin Grittner and Tom Lane with input from Florian Pflug and Robert Haas, based on problems encountered during conversion of Wisconsin Circuit Court trigger logic to plpgsql triggers.
2012-10-26 21:55:36 +02:00
HeapUpdateFailureData hufd;
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
/*
* get information on the (current) result relation
*/
resultRelInfo = estate->es_result_relation_info;
resultRelationDesc = resultRelInfo->ri_RelationDesc;
/* BEFORE ROW DELETE Triggers */
if (resultRelInfo->ri_TrigDesc &&
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
resultRelInfo->ri_TrigDesc->trig_delete_before_row)
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
{
bool dodelete;
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
dodelete = ExecBRDeleteTriggers(estate, epqstate, resultRelInfo,
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
tupleid);
if (!dodelete) /* "do nothing" */
return NULL;
}
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
/* INSTEAD OF ROW DELETE Triggers */
if (resultRelInfo->ri_TrigDesc &&
resultRelInfo->ri_TrigDesc->trig_delete_instead_row)
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
{
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
HeapTupleData tuple;
bool dodelete;
Assert(oldtuple != NULL);
tuple.t_data = oldtuple;
tuple.t_len = HeapTupleHeaderGetDatumLength(oldtuple);
ItemPointerSetInvalid(&(tuple.t_self));
tuple.t_tableOid = InvalidOid;
dodelete = ExecIRDeleteTriggers(estate, resultRelInfo, &tuple);
if (!dodelete) /* "do nothing" */
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
return NULL;
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
}
else
{
/*
* delete the tuple
*
* Note: if es_crosscheck_snapshot isn't InvalidSnapshot, we check
* that the row to be deleted is visible to that snapshot, and throw a
* can't-serialize error if not. This is a special-case behavior
* needed for referential integrity updates in transaction-snapshot
* mode transactions.
*/
ldelete:;
result = heap_delete(resultRelationDesc, tupleid,
estate->es_output_cid,
estate->es_crosscheck_snapshot,
Throw error if expiring tuple is again updated or deleted. This prevents surprising behavior when a FOR EACH ROW trigger BEFORE UPDATE or BEFORE DELETE directly or indirectly updates or deletes the the old row. Prior to this patch the requested action on the row could be silently ignored while all triggered actions based on the occurence of the requested action could be committed. One example of how this could happen is if the BEFORE DELETE trigger for a "parent" row deleted "children" which had trigger functions to update summary or status data on the parent. This also prevents similar surprising problems if the query has a volatile function which updates a target row while it is already being updated. There are related issues present in FOR UPDATE cursors and READ COMMITTED queries which are not handled by this patch. These issues need further evalution to determine what change, if any, is needed. Where the new error messages are generated, in most cases the best fix will be to move code from the BEFORE trigger to an AFTER trigger. Where this is not feasible, the trigger can avoid the error by re-issuing the triggering statement and returning NULL. Documentation changes will be submitted in a separate patch. Kevin Grittner and Tom Lane with input from Florian Pflug and Robert Haas, based on problems encountered during conversion of Wisconsin Circuit Court trigger logic to plpgsql triggers.
2012-10-26 21:55:36 +02:00
true /* wait for commit */,
&hufd);
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
switch (result)
{
case HeapTupleSelfUpdated:
Throw error if expiring tuple is again updated or deleted. This prevents surprising behavior when a FOR EACH ROW trigger BEFORE UPDATE or BEFORE DELETE directly or indirectly updates or deletes the the old row. Prior to this patch the requested action on the row could be silently ignored while all triggered actions based on the occurence of the requested action could be committed. One example of how this could happen is if the BEFORE DELETE trigger for a "parent" row deleted "children" which had trigger functions to update summary or status data on the parent. This also prevents similar surprising problems if the query has a volatile function which updates a target row while it is already being updated. There are related issues present in FOR UPDATE cursors and READ COMMITTED queries which are not handled by this patch. These issues need further evalution to determine what change, if any, is needed. Where the new error messages are generated, in most cases the best fix will be to move code from the BEFORE trigger to an AFTER trigger. Where this is not feasible, the trigger can avoid the error by re-issuing the triggering statement and returning NULL. Documentation changes will be submitted in a separate patch. Kevin Grittner and Tom Lane with input from Florian Pflug and Robert Haas, based on problems encountered during conversion of Wisconsin Circuit Court trigger logic to plpgsql triggers.
2012-10-26 21:55:36 +02:00
/*
* The target tuple was already updated or deleted by the
* current command, or by a later command in the current
* transaction. The former case is possible in a join DELETE
* where multiple tuples join to the same target tuple.
* This is somewhat questionable, but Postgres has always
* allowed it: we just ignore additional deletion attempts.
*
* The latter case arises if the tuple is modified by a
* command in a BEFORE trigger, or perhaps by a command in a
* volatile function used in the query. In such situations we
* should not ignore the deletion, but it is equally unsafe to
* proceed. We don't want to discard the original DELETE
* while keeping the triggered actions based on its deletion;
* and it would be no better to allow the original DELETE
* while discarding updates that it triggered. The row update
* carries some information that might be important according
* to business rules; so throwing an error is the only safe
* course.
*
* If a trigger actually intends this type of interaction,
* it can re-execute the DELETE and then return NULL to
* cancel the outer delete.
*/
if (hufd.cmax != estate->es_output_cid)
ereport(ERROR,
(errcode(ERRCODE_TRIGGERED_DATA_CHANGE_VIOLATION),
errmsg("tuple to be updated was already modified by an operation triggered by the current command"),
errhint("Consider using an AFTER trigger instead of a BEFORE trigger to propagate changes to other rows.")));
/* Else, already deleted by self; nothing to do */
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
return NULL;
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
case HeapTupleMayBeUpdated:
break;
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
case HeapTupleUpdated:
if (IsolationUsesXactSnapshot())
ereport(ERROR,
(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
errmsg("could not serialize access due to concurrent update")));
Throw error if expiring tuple is again updated or deleted. This prevents surprising behavior when a FOR EACH ROW trigger BEFORE UPDATE or BEFORE DELETE directly or indirectly updates or deletes the the old row. Prior to this patch the requested action on the row could be silently ignored while all triggered actions based on the occurence of the requested action could be committed. One example of how this could happen is if the BEFORE DELETE trigger for a "parent" row deleted "children" which had trigger functions to update summary or status data on the parent. This also prevents similar surprising problems if the query has a volatile function which updates a target row while it is already being updated. There are related issues present in FOR UPDATE cursors and READ COMMITTED queries which are not handled by this patch. These issues need further evalution to determine what change, if any, is needed. Where the new error messages are generated, in most cases the best fix will be to move code from the BEFORE trigger to an AFTER trigger. Where this is not feasible, the trigger can avoid the error by re-issuing the triggering statement and returning NULL. Documentation changes will be submitted in a separate patch. Kevin Grittner and Tom Lane with input from Florian Pflug and Robert Haas, based on problems encountered during conversion of Wisconsin Circuit Court trigger logic to plpgsql triggers.
2012-10-26 21:55:36 +02:00
if (!ItemPointerEquals(tupleid, &hufd.ctid))
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
{
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
TupleTableSlot *epqslot;
epqslot = EvalPlanQual(estate,
epqstate,
resultRelationDesc,
resultRelInfo->ri_RangeTableIndex,
Improve concurrency of foreign key locking This patch introduces two additional lock modes for tuples: "SELECT FOR KEY SHARE" and "SELECT FOR NO KEY UPDATE". These don't block each other, in contrast with already existing "SELECT FOR SHARE" and "SELECT FOR UPDATE". UPDATE commands that do not modify the values stored in the columns that are part of the key of the tuple now grab a SELECT FOR NO KEY UPDATE lock on the tuple, allowing them to proceed concurrently with tuple locks of the FOR KEY SHARE variety. Foreign key triggers now use FOR KEY SHARE instead of FOR SHARE; this means the concurrency improvement applies to them, which is the whole point of this patch. The added tuple lock semantics require some rejiggering of the multixact module, so that the locking level that each transaction is holding can be stored alongside its Xid. Also, multixacts now need to persist across server restarts and crashes, because they can now represent not only tuple locks, but also tuple updates. This means we need more careful tracking of lifetime of pg_multixact SLRU files; since they now persist longer, we require more infrastructure to figure out when they can be removed. pg_upgrade also needs to be careful to copy pg_multixact files over from the old server to the new, or at least part of multixact.c state, depending on the versions of the old and new servers. Tuple time qualification rules (HeapTupleSatisfies routines) need to be careful not to consider tuples with the "is multi" infomask bit set as being only locked; they might need to look up MultiXact values (i.e. possibly do pg_multixact I/O) to find out the Xid that updated a tuple, whereas they previously were assured to only use information readily available from the tuple header. This is considered acceptable, because the extra I/O would involve cases that would previously cause some commands to block waiting for concurrent transactions to finish. Another important change is the fact that locking tuples that have previously been updated causes the future versions to be marked as locked, too; this is essential for correctness of foreign key checks. This causes additional WAL-logging, also (there was previously a single WAL record for a locked tuple; now there are as many as updated copies of the tuple there exist.) With all this in place, contention related to tuples being checked by foreign key rules should be much reduced. As a bonus, the old behavior that a subtransaction grabbing a stronger tuple lock than the parent (sub)transaction held on a given tuple and later aborting caused the weaker lock to be lost, has been fixed. Many new spec files were added for isolation tester framework, to ensure overall behavior is sane. There's probably room for several more tests. There were several reviewers of this patch; in particular, Noah Misch and Andres Freund spent considerable time in it. Original idea for the patch came from Simon Riggs, after a problem report by Joel Jacobson. Most code is from me, with contributions from Marti Raudsepp, Alexander Shulgin, Noah Misch and Andres Freund. This patch was discussed in several pgsql-hackers threads; the most important start at the following message-ids: AANLkTimo9XVcEzfiBR-ut3KVNDkjm2Vxh+t8kAmWjPuv@mail.gmail.com 1290721684-sup-3951@alvh.no-ip.org 1294953201-sup-2099@alvh.no-ip.org 1320343602-sup-2290@alvh.no-ip.org 1339690386-sup-8927@alvh.no-ip.org 4FE5FF020200002500048A3D@gw.wicourts.gov 4FEAB90A0200002500048B7D@gw.wicourts.gov
2013-01-23 16:04:59 +01:00
LockTupleExclusive,
Throw error if expiring tuple is again updated or deleted. This prevents surprising behavior when a FOR EACH ROW trigger BEFORE UPDATE or BEFORE DELETE directly or indirectly updates or deletes the the old row. Prior to this patch the requested action on the row could be silently ignored while all triggered actions based on the occurence of the requested action could be committed. One example of how this could happen is if the BEFORE DELETE trigger for a "parent" row deleted "children" which had trigger functions to update summary or status data on the parent. This also prevents similar surprising problems if the query has a volatile function which updates a target row while it is already being updated. There are related issues present in FOR UPDATE cursors and READ COMMITTED queries which are not handled by this patch. These issues need further evalution to determine what change, if any, is needed. Where the new error messages are generated, in most cases the best fix will be to move code from the BEFORE trigger to an AFTER trigger. Where this is not feasible, the trigger can avoid the error by re-issuing the triggering statement and returning NULL. Documentation changes will be submitted in a separate patch. Kevin Grittner and Tom Lane with input from Florian Pflug and Robert Haas, based on problems encountered during conversion of Wisconsin Circuit Court trigger logic to plpgsql triggers.
2012-10-26 21:55:36 +02:00
&hufd.ctid,
hufd.xmax);
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
if (!TupIsNull(epqslot))
{
Throw error if expiring tuple is again updated or deleted. This prevents surprising behavior when a FOR EACH ROW trigger BEFORE UPDATE or BEFORE DELETE directly or indirectly updates or deletes the the old row. Prior to this patch the requested action on the row could be silently ignored while all triggered actions based on the occurence of the requested action could be committed. One example of how this could happen is if the BEFORE DELETE trigger for a "parent" row deleted "children" which had trigger functions to update summary or status data on the parent. This also prevents similar surprising problems if the query has a volatile function which updates a target row while it is already being updated. There are related issues present in FOR UPDATE cursors and READ COMMITTED queries which are not handled by this patch. These issues need further evalution to determine what change, if any, is needed. Where the new error messages are generated, in most cases the best fix will be to move code from the BEFORE trigger to an AFTER trigger. Where this is not feasible, the trigger can avoid the error by re-issuing the triggering statement and returning NULL. Documentation changes will be submitted in a separate patch. Kevin Grittner and Tom Lane with input from Florian Pflug and Robert Haas, based on problems encountered during conversion of Wisconsin Circuit Court trigger logic to plpgsql triggers.
2012-10-26 21:55:36 +02:00
*tupleid = hufd.ctid;
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
goto ldelete;
}
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
}
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
/* tuple already deleted; nothing to do */
return NULL;
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
default:
elog(ERROR, "unrecognized heap_delete status: %u", result);
return NULL;
}
/*
* Note: Normally one would think that we have to delete index tuples
* associated with the heap tuple now...
*
* ... but in POSTGRES, we have no need to do this because VACUUM will
* take care of it later. We can't delete index tuples immediately
* anyway, since the tuple is still visible to other transactions.
*/
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
}
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
if (canSetTag)
(estate->es_processed)++;
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
/* AFTER ROW DELETE Triggers */
ExecARDeleteTriggers(estate, resultRelInfo, tupleid);
/* Process RETURNING if present */
if (resultRelInfo->ri_projectReturning)
{
/*
* We have to put the target tuple into a slot, which means first we
* gotta fetch it. We can use the trigger tuple slot.
*/
TupleTableSlot *slot = estate->es_trig_tuple_slot;
TupleTableSlot *rslot;
HeapTupleData deltuple;
Buffer delbuffer;
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
if (oldtuple != NULL)
{
deltuple.t_data = oldtuple;
deltuple.t_len = HeapTupleHeaderGetDatumLength(oldtuple);
ItemPointerSetInvalid(&(deltuple.t_self));
deltuple.t_tableOid = InvalidOid;
delbuffer = InvalidBuffer;
}
else
{
deltuple.t_self = *tupleid;
if (!heap_fetch(resultRelationDesc, SnapshotAny,
&deltuple, &delbuffer, false, NULL))
elog(ERROR, "failed to fetch deleted tuple for DELETE RETURNING");
}
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
if (slot->tts_tupleDescriptor != RelationGetDescr(resultRelationDesc))
ExecSetSlotDescriptor(slot, RelationGetDescr(resultRelationDesc));
ExecStoreTuple(&deltuple, slot, InvalidBuffer, false);
rslot = ExecProcessReturning(resultRelInfo->ri_projectReturning,
slot, planSlot);
ExecClearTuple(slot);
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
if (BufferIsValid(delbuffer))
ReleaseBuffer(delbuffer);
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
return rslot;
}
return NULL;
}
/* ----------------------------------------------------------------
* ExecUpdate
*
* note: we can't run UPDATE queries with transactions
* off because UPDATEs are actually INSERTs and our
* scan will mistakenly loop forever, updating the tuple
* it just inserted.. This should be fixed but until it
* is, we don't want to get stuck in an infinite loop
* which corrupts your database..
*
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
* When updating a table, tupleid identifies the tuple to
* update and oldtuple is NULL. When updating a view, oldtuple
* is passed to the INSTEAD OF triggers and identifies what to
* update, and tupleid is invalid.
*
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
* Returns RETURNING result if any, otherwise NULL.
* ----------------------------------------------------------------
*/
static TupleTableSlot *
ExecUpdate(ItemPointer tupleid,
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
HeapTupleHeader oldtuple,
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
TupleTableSlot *slot,
TupleTableSlot *planSlot,
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
EPQState *epqstate,
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
EState *estate,
bool canSetTag)
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
{
HeapTuple tuple;
ResultRelInfo *resultRelInfo;
Relation resultRelationDesc;
HTSU_Result result;
Throw error if expiring tuple is again updated or deleted. This prevents surprising behavior when a FOR EACH ROW trigger BEFORE UPDATE or BEFORE DELETE directly or indirectly updates or deletes the the old row. Prior to this patch the requested action on the row could be silently ignored while all triggered actions based on the occurence of the requested action could be committed. One example of how this could happen is if the BEFORE DELETE trigger for a "parent" row deleted "children" which had trigger functions to update summary or status data on the parent. This also prevents similar surprising problems if the query has a volatile function which updates a target row while it is already being updated. There are related issues present in FOR UPDATE cursors and READ COMMITTED queries which are not handled by this patch. These issues need further evalution to determine what change, if any, is needed. Where the new error messages are generated, in most cases the best fix will be to move code from the BEFORE trigger to an AFTER trigger. Where this is not feasible, the trigger can avoid the error by re-issuing the triggering statement and returning NULL. Documentation changes will be submitted in a separate patch. Kevin Grittner and Tom Lane with input from Florian Pflug and Robert Haas, based on problems encountered during conversion of Wisconsin Circuit Court trigger logic to plpgsql triggers.
2012-10-26 21:55:36 +02:00
HeapUpdateFailureData hufd;
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
List *recheckIndexes = NIL;
/*
* abort the operation if not running transactions
*/
if (IsBootstrapProcessingMode())
elog(ERROR, "cannot UPDATE during bootstrap");
/*
* get the heap tuple out of the tuple table slot, making sure we have a
* writable copy
*/
tuple = ExecMaterializeSlot(slot);
/*
* get information on the (current) result relation
*/
resultRelInfo = estate->es_result_relation_info;
resultRelationDesc = resultRelInfo->ri_RelationDesc;
/* BEFORE ROW UPDATE Triggers */
if (resultRelInfo->ri_TrigDesc &&
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
resultRelInfo->ri_TrigDesc->trig_update_before_row)
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
{
Fix dangling-pointer problem in before-row update trigger processing. ExecUpdate checked for whether ExecBRUpdateTriggers had returned a new tuple value by seeing if the returned tuple was pointer-equal to the old one. But the "old one" was in estate->es_junkFilter's result slot, which would be scribbled on if we had done an EvalPlanQual update in response to a concurrent update of the target tuple; therefore we were comparing a dangling pointer to a live one. Given the right set of circumstances we could get a false match, resulting in not forcing the tuple to be stored in the slot we thought it was stored in. In the case reported by Maxim Boguk in bug #5798, this led to "cannot extract system attribute from virtual tuple" failures when trying to do "RETURNING ctid". I believe there is a very-low-probability chance of more serious errors, such as generating incorrect index entries based on the original rather than the trigger-modified version of the row. In HEAD, change all of ExecBRInsertTriggers, ExecIRInsertTriggers, ExecBRUpdateTriggers, and ExecIRUpdateTriggers so that they continue to have similar APIs. In the back branches I just changed ExecBRUpdateTriggers, since there is no bug in the ExecBRInsertTriggers case.
2011-02-22 03:18:04 +01:00
slot = ExecBRUpdateTriggers(estate, epqstate, resultRelInfo,
tupleid, slot);
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
Fix dangling-pointer problem in before-row update trigger processing. ExecUpdate checked for whether ExecBRUpdateTriggers had returned a new tuple value by seeing if the returned tuple was pointer-equal to the old one. But the "old one" was in estate->es_junkFilter's result slot, which would be scribbled on if we had done an EvalPlanQual update in response to a concurrent update of the target tuple; therefore we were comparing a dangling pointer to a live one. Given the right set of circumstances we could get a false match, resulting in not forcing the tuple to be stored in the slot we thought it was stored in. In the case reported by Maxim Boguk in bug #5798, this led to "cannot extract system attribute from virtual tuple" failures when trying to do "RETURNING ctid". I believe there is a very-low-probability chance of more serious errors, such as generating incorrect index entries based on the original rather than the trigger-modified version of the row. In HEAD, change all of ExecBRInsertTriggers, ExecIRInsertTriggers, ExecBRUpdateTriggers, and ExecIRUpdateTriggers so that they continue to have similar APIs. In the back branches I just changed ExecBRUpdateTriggers, since there is no bug in the ExecBRInsertTriggers case.
2011-02-22 03:18:04 +01:00
if (slot == NULL) /* "do nothing" */
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
return NULL;
Fix dangling-pointer problem in before-row update trigger processing. ExecUpdate checked for whether ExecBRUpdateTriggers had returned a new tuple value by seeing if the returned tuple was pointer-equal to the old one. But the "old one" was in estate->es_junkFilter's result slot, which would be scribbled on if we had done an EvalPlanQual update in response to a concurrent update of the target tuple; therefore we were comparing a dangling pointer to a live one. Given the right set of circumstances we could get a false match, resulting in not forcing the tuple to be stored in the slot we thought it was stored in. In the case reported by Maxim Boguk in bug #5798, this led to "cannot extract system attribute from virtual tuple" failures when trying to do "RETURNING ctid". I believe there is a very-low-probability chance of more serious errors, such as generating incorrect index entries based on the original rather than the trigger-modified version of the row. In HEAD, change all of ExecBRInsertTriggers, ExecIRInsertTriggers, ExecBRUpdateTriggers, and ExecIRUpdateTriggers so that they continue to have similar APIs. In the back branches I just changed ExecBRUpdateTriggers, since there is no bug in the ExecBRInsertTriggers case.
2011-02-22 03:18:04 +01:00
/* trigger might have changed tuple */
tuple = ExecMaterializeSlot(slot);
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
}
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
/* INSTEAD OF ROW UPDATE Triggers */
if (resultRelInfo->ri_TrigDesc &&
resultRelInfo->ri_TrigDesc->trig_update_instead_row)
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
{
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
HeapTupleData oldtup;
Assert(oldtuple != NULL);
oldtup.t_data = oldtuple;
oldtup.t_len = HeapTupleHeaderGetDatumLength(oldtuple);
ItemPointerSetInvalid(&(oldtup.t_self));
oldtup.t_tableOid = InvalidOid;
Fix dangling-pointer problem in before-row update trigger processing. ExecUpdate checked for whether ExecBRUpdateTriggers had returned a new tuple value by seeing if the returned tuple was pointer-equal to the old one. But the "old one" was in estate->es_junkFilter's result slot, which would be scribbled on if we had done an EvalPlanQual update in response to a concurrent update of the target tuple; therefore we were comparing a dangling pointer to a live one. Given the right set of circumstances we could get a false match, resulting in not forcing the tuple to be stored in the slot we thought it was stored in. In the case reported by Maxim Boguk in bug #5798, this led to "cannot extract system attribute from virtual tuple" failures when trying to do "RETURNING ctid". I believe there is a very-low-probability chance of more serious errors, such as generating incorrect index entries based on the original rather than the trigger-modified version of the row. In HEAD, change all of ExecBRInsertTriggers, ExecIRInsertTriggers, ExecBRUpdateTriggers, and ExecIRUpdateTriggers so that they continue to have similar APIs. In the back branches I just changed ExecBRUpdateTriggers, since there is no bug in the ExecBRInsertTriggers case.
2011-02-22 03:18:04 +01:00
slot = ExecIRUpdateTriggers(estate, resultRelInfo,
&oldtup, slot);
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
Fix dangling-pointer problem in before-row update trigger processing. ExecUpdate checked for whether ExecBRUpdateTriggers had returned a new tuple value by seeing if the returned tuple was pointer-equal to the old one. But the "old one" was in estate->es_junkFilter's result slot, which would be scribbled on if we had done an EvalPlanQual update in response to a concurrent update of the target tuple; therefore we were comparing a dangling pointer to a live one. Given the right set of circumstances we could get a false match, resulting in not forcing the tuple to be stored in the slot we thought it was stored in. In the case reported by Maxim Boguk in bug #5798, this led to "cannot extract system attribute from virtual tuple" failures when trying to do "RETURNING ctid". I believe there is a very-low-probability chance of more serious errors, such as generating incorrect index entries based on the original rather than the trigger-modified version of the row. In HEAD, change all of ExecBRInsertTriggers, ExecIRInsertTriggers, ExecBRUpdateTriggers, and ExecIRUpdateTriggers so that they continue to have similar APIs. In the back branches I just changed ExecBRUpdateTriggers, since there is no bug in the ExecBRInsertTriggers case.
2011-02-22 03:18:04 +01:00
if (slot == NULL) /* "do nothing" */
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
return NULL;
Fix dangling-pointer problem in before-row update trigger processing. ExecUpdate checked for whether ExecBRUpdateTriggers had returned a new tuple value by seeing if the returned tuple was pointer-equal to the old one. But the "old one" was in estate->es_junkFilter's result slot, which would be scribbled on if we had done an EvalPlanQual update in response to a concurrent update of the target tuple; therefore we were comparing a dangling pointer to a live one. Given the right set of circumstances we could get a false match, resulting in not forcing the tuple to be stored in the slot we thought it was stored in. In the case reported by Maxim Boguk in bug #5798, this led to "cannot extract system attribute from virtual tuple" failures when trying to do "RETURNING ctid". I believe there is a very-low-probability chance of more serious errors, such as generating incorrect index entries based on the original rather than the trigger-modified version of the row. In HEAD, change all of ExecBRInsertTriggers, ExecIRInsertTriggers, ExecBRUpdateTriggers, and ExecIRUpdateTriggers so that they continue to have similar APIs. In the back branches I just changed ExecBRUpdateTriggers, since there is no bug in the ExecBRInsertTriggers case.
2011-02-22 03:18:04 +01:00
/* trigger might have changed tuple */
tuple = ExecMaterializeSlot(slot);
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
}
else
{
Improve concurrency of foreign key locking This patch introduces two additional lock modes for tuples: "SELECT FOR KEY SHARE" and "SELECT FOR NO KEY UPDATE". These don't block each other, in contrast with already existing "SELECT FOR SHARE" and "SELECT FOR UPDATE". UPDATE commands that do not modify the values stored in the columns that are part of the key of the tuple now grab a SELECT FOR NO KEY UPDATE lock on the tuple, allowing them to proceed concurrently with tuple locks of the FOR KEY SHARE variety. Foreign key triggers now use FOR KEY SHARE instead of FOR SHARE; this means the concurrency improvement applies to them, which is the whole point of this patch. The added tuple lock semantics require some rejiggering of the multixact module, so that the locking level that each transaction is holding can be stored alongside its Xid. Also, multixacts now need to persist across server restarts and crashes, because they can now represent not only tuple locks, but also tuple updates. This means we need more careful tracking of lifetime of pg_multixact SLRU files; since they now persist longer, we require more infrastructure to figure out when they can be removed. pg_upgrade also needs to be careful to copy pg_multixact files over from the old server to the new, or at least part of multixact.c state, depending on the versions of the old and new servers. Tuple time qualification rules (HeapTupleSatisfies routines) need to be careful not to consider tuples with the "is multi" infomask bit set as being only locked; they might need to look up MultiXact values (i.e. possibly do pg_multixact I/O) to find out the Xid that updated a tuple, whereas they previously were assured to only use information readily available from the tuple header. This is considered acceptable, because the extra I/O would involve cases that would previously cause some commands to block waiting for concurrent transactions to finish. Another important change is the fact that locking tuples that have previously been updated causes the future versions to be marked as locked, too; this is essential for correctness of foreign key checks. This causes additional WAL-logging, also (there was previously a single WAL record for a locked tuple; now there are as many as updated copies of the tuple there exist.) With all this in place, contention related to tuples being checked by foreign key rules should be much reduced. As a bonus, the old behavior that a subtransaction grabbing a stronger tuple lock than the parent (sub)transaction held on a given tuple and later aborting caused the weaker lock to be lost, has been fixed. Many new spec files were added for isolation tester framework, to ensure overall behavior is sane. There's probably room for several more tests. There were several reviewers of this patch; in particular, Noah Misch and Andres Freund spent considerable time in it. Original idea for the patch came from Simon Riggs, after a problem report by Joel Jacobson. Most code is from me, with contributions from Marti Raudsepp, Alexander Shulgin, Noah Misch and Andres Freund. This patch was discussed in several pgsql-hackers threads; the most important start at the following message-ids: AANLkTimo9XVcEzfiBR-ut3KVNDkjm2Vxh+t8kAmWjPuv@mail.gmail.com 1290721684-sup-3951@alvh.no-ip.org 1294953201-sup-2099@alvh.no-ip.org 1320343602-sup-2290@alvh.no-ip.org 1339690386-sup-8927@alvh.no-ip.org 4FE5FF020200002500048A3D@gw.wicourts.gov 4FEAB90A0200002500048B7D@gw.wicourts.gov
2013-01-23 16:04:59 +01:00
LockTupleMode lockmode;
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
/*
* Check the constraints of the tuple
*
* If we generate a new candidate tuple after EvalPlanQual testing, we
* must loop back here and recheck constraints. (We don't need to
pgindent run before PG 9.1 beta 1.
2011-04-10 17:42:00 +02:00
* redo triggers, however. If there are any BEFORE triggers then
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
* trigger.c will have done heap_lock_tuple to lock the correct tuple,
* so there's no need to do them again.)
*/
lreplace:;
if (resultRelationDesc->rd_att->constr)
ExecConstraints(resultRelInfo, slot, estate);
/*
* replace the heap tuple
*
* Note: if es_crosscheck_snapshot isn't InvalidSnapshot, we check
* that the row to be updated is visible to that snapshot, and throw a
* can't-serialize error if not. This is a special-case behavior
* needed for referential integrity updates in transaction-snapshot
* mode transactions.
*/
result = heap_update(resultRelationDesc, tupleid, tuple,
estate->es_output_cid,
estate->es_crosscheck_snapshot,
Throw error if expiring tuple is again updated or deleted. This prevents surprising behavior when a FOR EACH ROW trigger BEFORE UPDATE or BEFORE DELETE directly or indirectly updates or deletes the the old row. Prior to this patch the requested action on the row could be silently ignored while all triggered actions based on the occurence of the requested action could be committed. One example of how this could happen is if the BEFORE DELETE trigger for a "parent" row deleted "children" which had trigger functions to update summary or status data on the parent. This also prevents similar surprising problems if the query has a volatile function which updates a target row while it is already being updated. There are related issues present in FOR UPDATE cursors and READ COMMITTED queries which are not handled by this patch. These issues need further evalution to determine what change, if any, is needed. Where the new error messages are generated, in most cases the best fix will be to move code from the BEFORE trigger to an AFTER trigger. Where this is not feasible, the trigger can avoid the error by re-issuing the triggering statement and returning NULL. Documentation changes will be submitted in a separate patch. Kevin Grittner and Tom Lane with input from Florian Pflug and Robert Haas, based on problems encountered during conversion of Wisconsin Circuit Court trigger logic to plpgsql triggers.
2012-10-26 21:55:36 +02:00
true /* wait for commit */,
Improve concurrency of foreign key locking This patch introduces two additional lock modes for tuples: "SELECT FOR KEY SHARE" and "SELECT FOR NO KEY UPDATE". These don't block each other, in contrast with already existing "SELECT FOR SHARE" and "SELECT FOR UPDATE". UPDATE commands that do not modify the values stored in the columns that are part of the key of the tuple now grab a SELECT FOR NO KEY UPDATE lock on the tuple, allowing them to proceed concurrently with tuple locks of the FOR KEY SHARE variety. Foreign key triggers now use FOR KEY SHARE instead of FOR SHARE; this means the concurrency improvement applies to them, which is the whole point of this patch. The added tuple lock semantics require some rejiggering of the multixact module, so that the locking level that each transaction is holding can be stored alongside its Xid. Also, multixacts now need to persist across server restarts and crashes, because they can now represent not only tuple locks, but also tuple updates. This means we need more careful tracking of lifetime of pg_multixact SLRU files; since they now persist longer, we require more infrastructure to figure out when they can be removed. pg_upgrade also needs to be careful to copy pg_multixact files over from the old server to the new, or at least part of multixact.c state, depending on the versions of the old and new servers. Tuple time qualification rules (HeapTupleSatisfies routines) need to be careful not to consider tuples with the "is multi" infomask bit set as being only locked; they might need to look up MultiXact values (i.e. possibly do pg_multixact I/O) to find out the Xid that updated a tuple, whereas they previously were assured to only use information readily available from the tuple header. This is considered acceptable, because the extra I/O would involve cases that would previously cause some commands to block waiting for concurrent transactions to finish. Another important change is the fact that locking tuples that have previously been updated causes the future versions to be marked as locked, too; this is essential for correctness of foreign key checks. This causes additional WAL-logging, also (there was previously a single WAL record for a locked tuple; now there are as many as updated copies of the tuple there exist.) With all this in place, contention related to tuples being checked by foreign key rules should be much reduced. As a bonus, the old behavior that a subtransaction grabbing a stronger tuple lock than the parent (sub)transaction held on a given tuple and later aborting caused the weaker lock to be lost, has been fixed. Many new spec files were added for isolation tester framework, to ensure overall behavior is sane. There's probably room for several more tests. There were several reviewers of this patch; in particular, Noah Misch and Andres Freund spent considerable time in it. Original idea for the patch came from Simon Riggs, after a problem report by Joel Jacobson. Most code is from me, with contributions from Marti Raudsepp, Alexander Shulgin, Noah Misch and Andres Freund. This patch was discussed in several pgsql-hackers threads; the most important start at the following message-ids: AANLkTimo9XVcEzfiBR-ut3KVNDkjm2Vxh+t8kAmWjPuv@mail.gmail.com 1290721684-sup-3951@alvh.no-ip.org 1294953201-sup-2099@alvh.no-ip.org 1320343602-sup-2290@alvh.no-ip.org 1339690386-sup-8927@alvh.no-ip.org 4FE5FF020200002500048A3D@gw.wicourts.gov 4FEAB90A0200002500048B7D@gw.wicourts.gov
2013-01-23 16:04:59 +01:00
&hufd, &lockmode);
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
switch (result)
{
case HeapTupleSelfUpdated:
Throw error if expiring tuple is again updated or deleted. This prevents surprising behavior when a FOR EACH ROW trigger BEFORE UPDATE or BEFORE DELETE directly or indirectly updates or deletes the the old row. Prior to this patch the requested action on the row could be silently ignored while all triggered actions based on the occurence of the requested action could be committed. One example of how this could happen is if the BEFORE DELETE trigger for a "parent" row deleted "children" which had trigger functions to update summary or status data on the parent. This also prevents similar surprising problems if the query has a volatile function which updates a target row while it is already being updated. There are related issues present in FOR UPDATE cursors and READ COMMITTED queries which are not handled by this patch. These issues need further evalution to determine what change, if any, is needed. Where the new error messages are generated, in most cases the best fix will be to move code from the BEFORE trigger to an AFTER trigger. Where this is not feasible, the trigger can avoid the error by re-issuing the triggering statement and returning NULL. Documentation changes will be submitted in a separate patch. Kevin Grittner and Tom Lane with input from Florian Pflug and Robert Haas, based on problems encountered during conversion of Wisconsin Circuit Court trigger logic to plpgsql triggers.
2012-10-26 21:55:36 +02:00
/*
* The target tuple was already updated or deleted by the
* current command, or by a later command in the current
* transaction. The former case is possible in a join UPDATE
* where multiple tuples join to the same target tuple.
* This is pretty questionable, but Postgres has always
* allowed it: we just execute the first update action and
* ignore additional update attempts.
*
* The latter case arises if the tuple is modified by a
* command in a BEFORE trigger, or perhaps by a command in a
* volatile function used in the query. In such situations we
* should not ignore the update, but it is equally unsafe to
* proceed. We don't want to discard the original UPDATE
* while keeping the triggered actions based on it; and we
* have no principled way to merge this update with the
* previous ones. So throwing an error is the only safe
* course.
*
* If a trigger actually intends this type of interaction,
* it can re-execute the UPDATE (assuming it can figure out
* how) and then return NULL to cancel the outer update.
*/
if (hufd.cmax != estate->es_output_cid)
ereport(ERROR,
(errcode(ERRCODE_TRIGGERED_DATA_CHANGE_VIOLATION),
errmsg("tuple to be updated was already modified by an operation triggered by the current command"),
errhint("Consider using an AFTER trigger instead of a BEFORE trigger to propagate changes to other rows.")));
/* Else, already updated by self; nothing to do */
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
return NULL;
case HeapTupleMayBeUpdated:
break;
case HeapTupleUpdated:
if (IsolationUsesXactSnapshot())
ereport(ERROR,
(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
errmsg("could not serialize access due to concurrent update")));
Throw error if expiring tuple is again updated or deleted. This prevents surprising behavior when a FOR EACH ROW trigger BEFORE UPDATE or BEFORE DELETE directly or indirectly updates or deletes the the old row. Prior to this patch the requested action on the row could be silently ignored while all triggered actions based on the occurence of the requested action could be committed. One example of how this could happen is if the BEFORE DELETE trigger for a "parent" row deleted "children" which had trigger functions to update summary or status data on the parent. This also prevents similar surprising problems if the query has a volatile function which updates a target row while it is already being updated. There are related issues present in FOR UPDATE cursors and READ COMMITTED queries which are not handled by this patch. These issues need further evalution to determine what change, if any, is needed. Where the new error messages are generated, in most cases the best fix will be to move code from the BEFORE trigger to an AFTER trigger. Where this is not feasible, the trigger can avoid the error by re-issuing the triggering statement and returning NULL. Documentation changes will be submitted in a separate patch. Kevin Grittner and Tom Lane with input from Florian Pflug and Robert Haas, based on problems encountered during conversion of Wisconsin Circuit Court trigger logic to plpgsql triggers.
2012-10-26 21:55:36 +02:00
if (!ItemPointerEquals(tupleid, &hufd.ctid))
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
{
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
TupleTableSlot *epqslot;
epqslot = EvalPlanQual(estate,
epqstate,
resultRelationDesc,
resultRelInfo->ri_RangeTableIndex,
Improve concurrency of foreign key locking This patch introduces two additional lock modes for tuples: "SELECT FOR KEY SHARE" and "SELECT FOR NO KEY UPDATE". These don't block each other, in contrast with already existing "SELECT FOR SHARE" and "SELECT FOR UPDATE". UPDATE commands that do not modify the values stored in the columns that are part of the key of the tuple now grab a SELECT FOR NO KEY UPDATE lock on the tuple, allowing them to proceed concurrently with tuple locks of the FOR KEY SHARE variety. Foreign key triggers now use FOR KEY SHARE instead of FOR SHARE; this means the concurrency improvement applies to them, which is the whole point of this patch. The added tuple lock semantics require some rejiggering of the multixact module, so that the locking level that each transaction is holding can be stored alongside its Xid. Also, multixacts now need to persist across server restarts and crashes, because they can now represent not only tuple locks, but also tuple updates. This means we need more careful tracking of lifetime of pg_multixact SLRU files; since they now persist longer, we require more infrastructure to figure out when they can be removed. pg_upgrade also needs to be careful to copy pg_multixact files over from the old server to the new, or at least part of multixact.c state, depending on the versions of the old and new servers. Tuple time qualification rules (HeapTupleSatisfies routines) need to be careful not to consider tuples with the "is multi" infomask bit set as being only locked; they might need to look up MultiXact values (i.e. possibly do pg_multixact I/O) to find out the Xid that updated a tuple, whereas they previously were assured to only use information readily available from the tuple header. This is considered acceptable, because the extra I/O would involve cases that would previously cause some commands to block waiting for concurrent transactions to finish. Another important change is the fact that locking tuples that have previously been updated causes the future versions to be marked as locked, too; this is essential for correctness of foreign key checks. This causes additional WAL-logging, also (there was previously a single WAL record for a locked tuple; now there are as many as updated copies of the tuple there exist.) With all this in place, contention related to tuples being checked by foreign key rules should be much reduced. As a bonus, the old behavior that a subtransaction grabbing a stronger tuple lock than the parent (sub)transaction held on a given tuple and later aborting caused the weaker lock to be lost, has been fixed. Many new spec files were added for isolation tester framework, to ensure overall behavior is sane. There's probably room for several more tests. There were several reviewers of this patch; in particular, Noah Misch and Andres Freund spent considerable time in it. Original idea for the patch came from Simon Riggs, after a problem report by Joel Jacobson. Most code is from me, with contributions from Marti Raudsepp, Alexander Shulgin, Noah Misch and Andres Freund. This patch was discussed in several pgsql-hackers threads; the most important start at the following message-ids: AANLkTimo9XVcEzfiBR-ut3KVNDkjm2Vxh+t8kAmWjPuv@mail.gmail.com 1290721684-sup-3951@alvh.no-ip.org 1294953201-sup-2099@alvh.no-ip.org 1320343602-sup-2290@alvh.no-ip.org 1339690386-sup-8927@alvh.no-ip.org 4FE5FF020200002500048A3D@gw.wicourts.gov 4FEAB90A0200002500048B7D@gw.wicourts.gov
2013-01-23 16:04:59 +01:00
lockmode,
Throw error if expiring tuple is again updated or deleted. This prevents surprising behavior when a FOR EACH ROW trigger BEFORE UPDATE or BEFORE DELETE directly or indirectly updates or deletes the the old row. Prior to this patch the requested action on the row could be silently ignored while all triggered actions based on the occurence of the requested action could be committed. One example of how this could happen is if the BEFORE DELETE trigger for a "parent" row deleted "children" which had trigger functions to update summary or status data on the parent. This also prevents similar surprising problems if the query has a volatile function which updates a target row while it is already being updated. There are related issues present in FOR UPDATE cursors and READ COMMITTED queries which are not handled by this patch. These issues need further evalution to determine what change, if any, is needed. Where the new error messages are generated, in most cases the best fix will be to move code from the BEFORE trigger to an AFTER trigger. Where this is not feasible, the trigger can avoid the error by re-issuing the triggering statement and returning NULL. Documentation changes will be submitted in a separate patch. Kevin Grittner and Tom Lane with input from Florian Pflug and Robert Haas, based on problems encountered during conversion of Wisconsin Circuit Court trigger logic to plpgsql triggers.
2012-10-26 21:55:36 +02:00
&hufd.ctid,
hufd.xmax);
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
if (!TupIsNull(epqslot))
{
Throw error if expiring tuple is again updated or deleted. This prevents surprising behavior when a FOR EACH ROW trigger BEFORE UPDATE or BEFORE DELETE directly or indirectly updates or deletes the the old row. Prior to this patch the requested action on the row could be silently ignored while all triggered actions based on the occurence of the requested action could be committed. One example of how this could happen is if the BEFORE DELETE trigger for a "parent" row deleted "children" which had trigger functions to update summary or status data on the parent. This also prevents similar surprising problems if the query has a volatile function which updates a target row while it is already being updated. There are related issues present in FOR UPDATE cursors and READ COMMITTED queries which are not handled by this patch. These issues need further evalution to determine what change, if any, is needed. Where the new error messages are generated, in most cases the best fix will be to move code from the BEFORE trigger to an AFTER trigger. Where this is not feasible, the trigger can avoid the error by re-issuing the triggering statement and returning NULL. Documentation changes will be submitted in a separate patch. Kevin Grittner and Tom Lane with input from Florian Pflug and Robert Haas, based on problems encountered during conversion of Wisconsin Circuit Court trigger logic to plpgsql triggers.
2012-10-26 21:55:36 +02:00
*tupleid = hufd.ctid;
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
slot = ExecFilterJunk(resultRelInfo->ri_junkFilter, epqslot);
tuple = ExecMaterializeSlot(slot);
goto lreplace;
}
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
}
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
/* tuple already deleted; nothing to do */
return NULL;
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
default:
elog(ERROR, "unrecognized heap_update status: %u", result);
return NULL;
}
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
/*
* Note: instead of having to update the old index tuples associated
pgindent run before PG 9.1 beta 1.
2011-04-10 17:42:00 +02:00
* with the heap tuple, all we do is form and insert new index tuples.
* This is because UPDATEs are actually DELETEs and INSERTs, and index
* tuple deletion is done later by VACUUM (see notes in ExecDelete).
* All we do here is insert new index tuples. -cim 9/27/89
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
*/
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
/*
* insert index entries for tuple
*
* Note: heap_update returns the tid (location) of the new tuple in
* the t_self field.
*
* If it's a HOT update, we mustn't insert new index entries.
*/
if (resultRelInfo->ri_NumIndices > 0 && !HeapTupleIsHeapOnly(tuple))
recheckIndexes = ExecInsertIndexTuples(slot, &(tuple->t_self),
estate);
}
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
if (canSetTag)
(estate->es_processed)++;
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
/* AFTER ROW UPDATE Triggers */
ExecARUpdateTriggers(estate, resultRelInfo, tupleid, tuple,
recheckIndexes);
Fix memory leak created by deferrable-index-constraints patches. We need to free the OID list returned by ExecInsertIndexTuples to avoid a query-lifespan memory leak. When many rows require rechecking, this can be a significant leak --- it's even more than the space used for the queued trigger events. Dean Rasheed
2010-01-31 19:15:39 +01:00
list_free(recheckIndexes);
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
/* Process RETURNING if present */
if (resultRelInfo->ri_projectReturning)
return ExecProcessReturning(resultRelInfo->ri_projectReturning,
slot, planSlot);
return NULL;
}
/*
* Process BEFORE EACH STATEMENT triggers
*/
static void
fireBSTriggers(ModifyTableState *node)
{
switch (node->operation)
{
case CMD_INSERT:
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
ExecBSInsertTriggers(node->ps.state, node->resultRelInfo);
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
break;
case CMD_UPDATE:
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
ExecBSUpdateTriggers(node->ps.state, node->resultRelInfo);
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
break;
case CMD_DELETE:
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
ExecBSDeleteTriggers(node->ps.state, node->resultRelInfo);
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
break;
default:
elog(ERROR, "unknown operation");
break;
}
}
/*
* Process AFTER EACH STATEMENT triggers
*/
static void
fireASTriggers(ModifyTableState *node)
{
switch (node->operation)
{
case CMD_INSERT:
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
ExecASInsertTriggers(node->ps.state, node->resultRelInfo);
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
break;
case CMD_UPDATE:
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
ExecASUpdateTriggers(node->ps.state, node->resultRelInfo);
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
break;
case CMD_DELETE:
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
ExecASDeleteTriggers(node->ps.state, node->resultRelInfo);
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
break;
default:
elog(ERROR, "unknown operation");
break;
}
}
/* ----------------------------------------------------------------
* ExecModifyTable
*
* Perform table modifications as required, and return RETURNING results
* if needed.
* ----------------------------------------------------------------
*/
TupleTableSlot *
ExecModifyTable(ModifyTableState *node)
{
pgindent run for 9.0
2010-02-26 03:01:40 +01:00
EState *estate = node->ps.state;
CmdType operation = node->operation;
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
ResultRelInfo *saved_resultRelInfo;
ResultRelInfo *resultRelInfo;
pgindent run for 9.0
2010-02-26 03:01:40 +01:00
PlanState *subplanstate;
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
JunkFilter *junkfilter;
TupleTableSlot *slot;
TupleTableSlot *planSlot;
ItemPointer tupleid = NULL;
ItemPointerData tuple_ctid;
pgindent run before PG 9.1 beta 1.
2011-04-10 17:42:00 +02:00
HeapTupleHeader oldtuple = NULL;
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
Fix handling of data-modifying CTE subplans in EvalPlanQual. We can't just skip initializing such subplans, because the referencing CTE node will expect to find the subplan available when it initializes. That in turn means that ExecInitModifyTable must allow the case (which actually it needed to do anyway, since there's no guarantee that ModifyTable is exactly at the top of the CTE plan tree). So move the complaint about not being allowed in EvalPlanQual mode to execution instead of initialization. Testing turned up yet another problem, which is that we'd try to re-initialize the result relation's index list, leading to leaks and dangling pointers. Per report from Phil Sorber. Back-patch to 9.1 where data-modifying CTEs were introduced.
2012-01-28 23:43:57 +01:00
/*
* This should NOT get called during EvalPlanQual; we should have passed a
* subplan tree to EvalPlanQual, instead. Use a runtime test not just
* Assert because this condition is easy to miss in testing. (Note:
* although ModifyTable should not get executed within an EvalPlanQual
* operation, we do have to allow it to be initialized and shut down in
* case it is within a CTE subplan. Hence this test must be here, not in
* ExecInitModifyTable.)
*/
if (estate->es_epqTuple != NULL)
elog(ERROR, "ModifyTable should not be called during EvalPlanQual");
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
/*
* If we've already completed processing, don't try to do more. We need
* this test because ExecPostprocessPlan might call us an extra time, and
* our subplan's nodes aren't necessarily robust against being called
* extra times.
*/
if (node->mt_done)
return NULL;
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
/*
* On first call, fire BEFORE STATEMENT triggers before proceeding.
*/
if (node->fireBSTriggers)
{
fireBSTriggers(node);
node->fireBSTriggers = false;
}
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
/* Preload local variables */
resultRelInfo = node->resultRelInfo + node->mt_whichplan;
subplanstate = node->mt_plans[node->mt_whichplan];
junkfilter = resultRelInfo->ri_junkFilter;
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
/*
* es_result_relation_info must point to the currently active result
pgindent run before PG 9.1 beta 1.
2011-04-10 17:42:00 +02:00
* relation while we are within this ModifyTable node. Even though
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
* ModifyTable nodes can't be nested statically, they can be nested
* dynamically (since our subplan could include a reference to a modifying
* CTE). So we have to save and restore the caller's value.
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
*/
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
saved_resultRelInfo = estate->es_result_relation_info;
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
estate->es_result_relation_info = resultRelInfo;
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
/*
* Fetch rows from subplan(s), and execute the required table modification
* for each row.
*/
for (;;)
{
Reset the per-output-tuple exprcontext each time through the main loop in ExecModifyTable(). This avoids memory leakage when trigger functions leave junk behind in that context (as they more or less must). Problem and solution identified by Dean Rasheed. I'm a bit concerned about the longevity of this solution --- once a plan can have multiple ModifyTable nodes, we are very possibly going to have to do something different. But it should hold up for 9.0.
2010-08-18 23:52:24 +02:00
/*
pgindent run before PG 9.1 beta 1.
2011-04-10 17:42:00 +02:00
* Reset the per-output-tuple exprcontext. This is needed because
Reset the per-output-tuple exprcontext each time through the main loop in ExecModifyTable(). This avoids memory leakage when trigger functions leave junk behind in that context (as they more or less must). Problem and solution identified by Dean Rasheed. I'm a bit concerned about the longevity of this solution --- once a plan can have multiple ModifyTable nodes, we are very possibly going to have to do something different. But it should hold up for 9.0.
2010-08-18 23:52:24 +02:00
* triggers expect to use that context as workspace. It's a bit ugly
* to do this below the top level of the plan, however. We might need
* to rethink this later.
*/
ResetPerTupleExprContext(estate);
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
planSlot = ExecProcNode(subplanstate);
if (TupIsNull(planSlot))
{
/* advance to next subplan if any */
node->mt_whichplan++;
if (node->mt_whichplan < node->mt_nplans)
{
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
resultRelInfo++;
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
subplanstate = node->mt_plans[node->mt_whichplan];
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
junkfilter = resultRelInfo->ri_junkFilter;
estate->es_result_relation_info = resultRelInfo;
Fix PlanRowMark/ExecRowMark structures to handle inheritance correctly. In an inherited UPDATE/DELETE, each target table has its own subplan, because it might have a column set different from other targets. This means that the resjunk columns we add to support EvalPlanQual might be at different physical column numbers in each subplan. The EvalPlanQual rewrite I did for 9.0 failed to account for this, resulting in possible misbehavior or even crashes during concurrent updates to the same row, as seen in a recent report from Gordon Shannon. Revise the data structure so that we track resjunk column numbers separately for each subplan. I also chose to move responsibility for identifying the physical column numbers back to executor startup, instead of assuming that numbers derived during preprocess_targetlist would stay valid throughout subsequent massaging of the plan. That's a bit slower, so we might want to consider undoing it someday; but it would complicate the patch considerably and didn't seem justifiable in a bug fix that has to be back-patched to 9.0.
2011-01-13 02:47:02 +01:00
EvalPlanQualSetPlan(&node->mt_epqstate, subplanstate->plan,
node->mt_arowmarks[node->mt_whichplan]);
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
continue;
}
else
break;
}
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
EvalPlanQualSetSlot(&node->mt_epqstate, planSlot);
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
slot = planSlot;
if (junkfilter != NULL)
{
/*
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
* extract the 'ctid' or 'wholerow' junk attribute.
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
*/
if (operation == CMD_UPDATE || operation == CMD_DELETE)
{
Datum datum;
bool isNull;
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
if (resultRelInfo->ri_RelationDesc->rd_rel->relkind == RELKIND_RELATION)
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
{
datum = ExecGetJunkAttribute(slot,
junkfilter->jf_junkAttNo,
&isNull);
/* shouldn't ever get a null result... */
if (isNull)
elog(ERROR, "ctid is NULL");
tupleid = (ItemPointer) DatumGetPointer(datum);
pgindent run before PG 9.1 beta 1.
2011-04-10 17:42:00 +02:00
tuple_ctid = *tupleid; /* be sure we don't free
* ctid!! */
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
tupleid = &tuple_ctid;
}
else
{
datum = ExecGetJunkAttribute(slot,
junkfilter->jf_junkAttNo,
&isNull);
/* shouldn't ever get a null result... */
if (isNull)
elog(ERROR, "wholerow is NULL");
oldtuple = DatumGetHeapTupleHeader(datum);
}
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
}
/*
* apply the junkfilter if needed.
*/
if (operation != CMD_DELETE)
slot = ExecFilterJunk(junkfilter, slot);
}
switch (operation)
{
case CMD_INSERT:
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
slot = ExecInsert(slot, planSlot, estate, node->canSetTag);
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
break;
case CMD_UPDATE:
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
slot = ExecUpdate(tupleid, oldtuple, slot, planSlot,
pgindent run before PG 9.1 beta 1.
2011-04-10 17:42:00 +02:00
&node->mt_epqstate, estate, node->canSetTag);
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
break;
case CMD_DELETE:
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
slot = ExecDelete(tupleid, oldtuple, planSlot,
pgindent run before PG 9.1 beta 1.
2011-04-10 17:42:00 +02:00
&node->mt_epqstate, estate, node->canSetTag);
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
break;
default:
elog(ERROR, "unknown operation");
break;
}
/*
* If we got a RETURNING result, return it to caller. We'll continue
* the work on next call.
*/
if (slot)
{
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
estate->es_result_relation_info = saved_resultRelInfo;
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
return slot;
}
}
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
/* Restore es_result_relation_info before exiting */
estate->es_result_relation_info = saved_resultRelInfo;
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
/*
* We're done, but fire AFTER STATEMENT triggers before exiting.
*/
fireASTriggers(node);
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
node->mt_done = true;
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
return NULL;
}
/* ----------------------------------------------------------------
* ExecInitModifyTable
* ----------------------------------------------------------------
*/
ModifyTableState *
ExecInitModifyTable(ModifyTable *node, EState *estate, int eflags)
{
ModifyTableState *mtstate;
CmdType operation = node->operation;
int nplans = list_length(node->plans);
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
ResultRelInfo *saved_resultRelInfo;
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
ResultRelInfo *resultRelInfo;
TupleDesc tupDesc;
Plan *subplan;
ListCell *l;
int i;
/* check for unsupported flags */
Assert(!(eflags & (EXEC_FLAG_BACKWARD | EXEC_FLAG_MARK)));
/*
* create state structure
*/
mtstate = makeNode(ModifyTableState);
mtstate->ps.plan = (Plan *) node;
mtstate->ps.state = estate;
mtstate->ps.targetlist = NIL; /* not actually used */
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
mtstate->operation = operation;
mtstate->canSetTag = node->canSetTag;
mtstate->mt_done = false;
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
mtstate->mt_plans = (PlanState **) palloc0(sizeof(PlanState *) * nplans);
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
mtstate->resultRelInfo = estate->es_result_relations + node->resultRelIndex;
Fix PlanRowMark/ExecRowMark structures to handle inheritance correctly. In an inherited UPDATE/DELETE, each target table has its own subplan, because it might have a column set different from other targets. This means that the resjunk columns we add to support EvalPlanQual might be at different physical column numbers in each subplan. The EvalPlanQual rewrite I did for 9.0 failed to account for this, resulting in possible misbehavior or even crashes during concurrent updates to the same row, as seen in a recent report from Gordon Shannon. Revise the data structure so that we track resjunk column numbers separately for each subplan. I also chose to move responsibility for identifying the physical column numbers back to executor startup, instead of assuming that numbers derived during preprocess_targetlist would stay valid throughout subsequent massaging of the plan. That's a bit slower, so we might want to consider undoing it someday; but it would complicate the patch considerably and didn't seem justifiable in a bug fix that has to be back-patched to 9.0.
2011-01-13 02:47:02 +01:00
mtstate->mt_arowmarks = (List **) palloc0(sizeof(List *) * nplans);
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
mtstate->mt_nplans = nplans;
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
Fix PlanRowMark/ExecRowMark structures to handle inheritance correctly. In an inherited UPDATE/DELETE, each target table has its own subplan, because it might have a column set different from other targets. This means that the resjunk columns we add to support EvalPlanQual might be at different physical column numbers in each subplan. The EvalPlanQual rewrite I did for 9.0 failed to account for this, resulting in possible misbehavior or even crashes during concurrent updates to the same row, as seen in a recent report from Gordon Shannon. Revise the data structure so that we track resjunk column numbers separately for each subplan. I also chose to move responsibility for identifying the physical column numbers back to executor startup, instead of assuming that numbers derived during preprocess_targetlist would stay valid throughout subsequent massaging of the plan. That's a bit slower, so we might want to consider undoing it someday; but it would complicate the patch considerably and didn't seem justifiable in a bug fix that has to be back-patched to 9.0.
2011-01-13 02:47:02 +01:00
/* set up epqstate with dummy subplan data for the moment */
EvalPlanQualInit(&mtstate->mt_epqstate, estate, NULL, NIL, node->epqParam);
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
mtstate->fireBSTriggers = true;
/*
* call ExecInitNode on each of the plans to be executed and save the
pgindent run before PG 9.1 beta 1.
2011-04-10 17:42:00 +02:00
* results into the array "mt_plans". This is also a convenient place to
* verify that the proposed target relations are valid and open their
* indexes for insertion of new index entries. Note we *must* set
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
* estate->es_result_relation_info correctly while we initialize each
* sub-plan; ExecContextForcesOids depends on that!
*/
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
saved_resultRelInfo = estate->es_result_relation_info;
resultRelInfo = mtstate->resultRelInfo;
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
i = 0;
foreach(l, node->plans)
{
subplan = (Plan *) lfirst(l);
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
/*
* Verify result relation is a valid target for the current operation
*/
CheckValidResultRel(resultRelInfo->ri_RelationDesc, operation);
/*
* If there are indices on the result relation, open them and save
* descriptors in the result relation info, so that we can add new
pgindent run before PG 9.1 beta 1.
2011-04-10 17:42:00 +02:00
* index entries for the tuples we add/update. We need not do this
Run pgindent on 9.2 source tree in preparation for first 9.3 commit-fest.
2012-06-10 21:20:04 +02:00
* for a DELETE, however, since deletion doesn't affect indexes. Also,
* inside an EvalPlanQual operation, the indexes might be open
Fix handling of data-modifying CTE subplans in EvalPlanQual. We can't just skip initializing such subplans, because the referencing CTE node will expect to find the subplan available when it initializes. That in turn means that ExecInitModifyTable must allow the case (which actually it needed to do anyway, since there's no guarantee that ModifyTable is exactly at the top of the CTE plan tree). So move the complaint about not being allowed in EvalPlanQual mode to execution instead of initialization. Testing turned up yet another problem, which is that we'd try to re-initialize the result relation's index list, leading to leaks and dangling pointers. Per report from Phil Sorber. Back-patch to 9.1 where data-modifying CTEs were introduced.
2012-01-28 23:43:57 +01:00
* already, since we share the resultrel state with the original
* query.
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
*/
if (resultRelInfo->ri_RelationDesc->rd_rel->relhasindex &&
Fix handling of data-modifying CTE subplans in EvalPlanQual. We can't just skip initializing such subplans, because the referencing CTE node will expect to find the subplan available when it initializes. That in turn means that ExecInitModifyTable must allow the case (which actually it needed to do anyway, since there's no guarantee that ModifyTable is exactly at the top of the CTE plan tree). So move the complaint about not being allowed in EvalPlanQual mode to execution instead of initialization. Testing turned up yet another problem, which is that we'd try to re-initialize the result relation's index list, leading to leaks and dangling pointers. Per report from Phil Sorber. Back-patch to 9.1 where data-modifying CTEs were introduced.
2012-01-28 23:43:57 +01:00
operation != CMD_DELETE &&
resultRelInfo->ri_IndexRelationDescs == NULL)
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
ExecOpenIndices(resultRelInfo);
/* Now init the plan for this result rel */
estate->es_result_relation_info = resultRelInfo;
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
mtstate->mt_plans[i] = ExecInitNode(subplan, estate, eflags);
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
resultRelInfo++;
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
i++;
}
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
estate->es_result_relation_info = saved_resultRelInfo;
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
/*
* Initialize RETURNING projections if needed.
*/
if (node->returningLists)
{
TupleTableSlot *slot;
ExprContext *econtext;
/*
pgindent run for 9.0
2010-02-26 03:01:40 +01:00
* Initialize result tuple slot and assign its rowtype using the first
* RETURNING list. We assume the rest will look the same.
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
*/
tupDesc = ExecTypeFromTL((List *) linitial(node->returningLists),
false);
/* Set up a slot for the output of the RETURNING projection(s) */
ExecInitResultTupleSlot(estate, &mtstate->ps);
ExecAssignResultType(&mtstate->ps, tupDesc);
slot = mtstate->ps.ps_ResultTupleSlot;
/* Need an econtext too */
econtext = CreateExprContext(estate);
mtstate->ps.ps_ExprContext = econtext;
/*
* Build a projection for each result rel.
*/
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
resultRelInfo = mtstate->resultRelInfo;
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
foreach(l, node->returningLists)
{
List *rlist = (List *) lfirst(l);
List *rliststate;
rliststate = (List *) ExecInitExpr((Expr *) rlist, &mtstate->ps);
resultRelInfo->ri_projectReturning =
ExecBuildProjectionInfo(rliststate, econtext, slot,
resultRelInfo->ri_RelationDesc->rd_att);
resultRelInfo++;
}
}
else
{
/*
pgindent run for 9.0
2010-02-26 03:01:40 +01:00
* We still must construct a dummy result tuple type, because InitPlan
* expects one (maybe should change that?).
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
*/
tupDesc = ExecTypeFromTL(NIL, false);
ExecInitResultTupleSlot(estate, &mtstate->ps);
ExecAssignResultType(&mtstate->ps, tupDesc);
mtstate->ps.ps_ExprContext = NULL;
}
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
/*
pgindent run for 9.0
2010-02-26 03:01:40 +01:00
* If we have any secondary relations in an UPDATE or DELETE, they need to
* be treated like non-locked relations in SELECT FOR UPDATE, ie, the
* EvalPlanQual mechanism needs to be told about them. Locate the
* relevant ExecRowMarks.
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
*/
foreach(l, node->rowMarks)
{
PlanRowMark *rc = (PlanRowMark *) lfirst(l);
Fix PlanRowMark/ExecRowMark structures to handle inheritance correctly. In an inherited UPDATE/DELETE, each target table has its own subplan, because it might have a column set different from other targets. This means that the resjunk columns we add to support EvalPlanQual might be at different physical column numbers in each subplan. The EvalPlanQual rewrite I did for 9.0 failed to account for this, resulting in possible misbehavior or even crashes during concurrent updates to the same row, as seen in a recent report from Gordon Shannon. Revise the data structure so that we track resjunk column numbers separately for each subplan. I also chose to move responsibility for identifying the physical column numbers back to executor startup, instead of assuming that numbers derived during preprocess_targetlist would stay valid throughout subsequent massaging of the plan. That's a bit slower, so we might want to consider undoing it someday; but it would complicate the patch considerably and didn't seem justifiable in a bug fix that has to be back-patched to 9.0.
2011-01-13 02:47:02 +01:00
ExecRowMark *erm;
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
Assert(IsA(rc, PlanRowMark));
/* ignore "parent" rowmarks; they are irrelevant at runtime */
if (rc->isParent)
continue;
Fix PlanRowMark/ExecRowMark structures to handle inheritance correctly. In an inherited UPDATE/DELETE, each target table has its own subplan, because it might have a column set different from other targets. This means that the resjunk columns we add to support EvalPlanQual might be at different physical column numbers in each subplan. The EvalPlanQual rewrite I did for 9.0 failed to account for this, resulting in possible misbehavior or even crashes during concurrent updates to the same row, as seen in a recent report from Gordon Shannon. Revise the data structure so that we track resjunk column numbers separately for each subplan. I also chose to move responsibility for identifying the physical column numbers back to executor startup, instead of assuming that numbers derived during preprocess_targetlist would stay valid throughout subsequent massaging of the plan. That's a bit slower, so we might want to consider undoing it someday; but it would complicate the patch considerably and didn't seem justifiable in a bug fix that has to be back-patched to 9.0.
2011-01-13 02:47:02 +01:00
/* find ExecRowMark (same for all subplans) */
erm = ExecFindRowMark(estate, rc->rti);
/* build ExecAuxRowMark for each subplan */
for (i = 0; i < nplans; 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
{
Fix PlanRowMark/ExecRowMark structures to handle inheritance correctly. In an inherited UPDATE/DELETE, each target table has its own subplan, because it might have a column set different from other targets. This means that the resjunk columns we add to support EvalPlanQual might be at different physical column numbers in each subplan. The EvalPlanQual rewrite I did for 9.0 failed to account for this, resulting in possible misbehavior or even crashes during concurrent updates to the same row, as seen in a recent report from Gordon Shannon. Revise the data structure so that we track resjunk column numbers separately for each subplan. I also chose to move responsibility for identifying the physical column numbers back to executor startup, instead of assuming that numbers derived during preprocess_targetlist would stay valid throughout subsequent massaging of the plan. That's a bit slower, so we might want to consider undoing it someday; but it would complicate the patch considerably and didn't seem justifiable in a bug fix that has to be back-patched to 9.0.
2011-01-13 02:47:02 +01:00
ExecAuxRowMark *aerm;
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
Fix PlanRowMark/ExecRowMark structures to handle inheritance correctly. In an inherited UPDATE/DELETE, each target table has its own subplan, because it might have a column set different from other targets. This means that the resjunk columns we add to support EvalPlanQual might be at different physical column numbers in each subplan. The EvalPlanQual rewrite I did for 9.0 failed to account for this, resulting in possible misbehavior or even crashes during concurrent updates to the same row, as seen in a recent report from Gordon Shannon. Revise the data structure so that we track resjunk column numbers separately for each subplan. I also chose to move responsibility for identifying the physical column numbers back to executor startup, instead of assuming that numbers derived during preprocess_targetlist would stay valid throughout subsequent massaging of the plan. That's a bit slower, so we might want to consider undoing it someday; but it would complicate the patch considerably and didn't seem justifiable in a bug fix that has to be back-patched to 9.0.
2011-01-13 02:47:02 +01:00
subplan = mtstate->mt_plans[i]->plan;
aerm = ExecBuildAuxRowMark(erm, subplan->targetlist);
mtstate->mt_arowmarks[i] = lappend(mtstate->mt_arowmarks[i], aerm);
}
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
}
Fix PlanRowMark/ExecRowMark structures to handle inheritance correctly. In an inherited UPDATE/DELETE, each target table has its own subplan, because it might have a column set different from other targets. This means that the resjunk columns we add to support EvalPlanQual might be at different physical column numbers in each subplan. The EvalPlanQual rewrite I did for 9.0 failed to account for this, resulting in possible misbehavior or even crashes during concurrent updates to the same row, as seen in a recent report from Gordon Shannon. Revise the data structure so that we track resjunk column numbers separately for each subplan. I also chose to move responsibility for identifying the physical column numbers back to executor startup, instead of assuming that numbers derived during preprocess_targetlist would stay valid throughout subsequent massaging of the plan. That's a bit slower, so we might want to consider undoing it someday; but it would complicate the patch considerably and didn't seem justifiable in a bug fix that has to be back-patched to 9.0.
2011-01-13 02:47:02 +01:00
/* select first subplan */
mtstate->mt_whichplan = 0;
subplan = (Plan *) linitial(node->plans);
EvalPlanQualSetPlan(&mtstate->mt_epqstate, subplan,
mtstate->mt_arowmarks[0]);
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
/*
* Initialize the junk filter(s) if needed. INSERT queries need a filter
pgindent run for 9.0
2010-02-26 03:01:40 +01:00
* if there are any junk attrs in the tlist. UPDATE and DELETE always
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
* need a filter, since there's always a junk 'ctid' or 'wholerow'
* attribute present --- no need to look first.
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
*
* If there are multiple result relations, each one needs its own junk
pgindent run for 9.0
2010-02-26 03:01:40 +01:00
* filter. Note multiple rels are only possible for UPDATE/DELETE, so we
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
* can't be fooled by some needing a filter and some not.
*
* This section of code is also a convenient place to verify that the
* output of an INSERT or UPDATE matches the target table(s).
*/
{
bool junk_filter_needed = false;
switch (operation)
{
case CMD_INSERT:
foreach(l, subplan->targetlist)
{
TargetEntry *tle = (TargetEntry *) lfirst(l);
if (tle->resjunk)
{
junk_filter_needed = true;
break;
}
}
break;
case CMD_UPDATE:
case CMD_DELETE:
junk_filter_needed = true;
break;
default:
elog(ERROR, "unknown operation");
break;
}
if (junk_filter_needed)
{
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
resultRelInfo = mtstate->resultRelInfo;
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
for (i = 0; i < nplans; i++)
{
JunkFilter *j;
subplan = mtstate->mt_plans[i]->plan;
if (operation == CMD_INSERT || operation == CMD_UPDATE)
ExecCheckPlanOutput(resultRelInfo->ri_RelationDesc,
subplan->targetlist);
j = ExecInitJunkFilter(subplan->targetlist,
resultRelInfo->ri_RelationDesc->rd_att->tdhasoid,
ExecInitExtraTupleSlot(estate));
if (operation == CMD_UPDATE || operation == CMD_DELETE)
{
Support triggers on views. This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 19:43:33 +02:00
/* For UPDATE/DELETE, find the appropriate junk attr now */
if (resultRelInfo->ri_RelationDesc->rd_rel->relkind == RELKIND_RELATION)
{
j->jf_junkAttNo = ExecFindJunkAttribute(j, "ctid");
if (!AttributeNumberIsValid(j->jf_junkAttNo))
elog(ERROR, "could not find junk ctid column");
}
else
{
j->jf_junkAttNo = ExecFindJunkAttribute(j, "wholerow");
if (!AttributeNumberIsValid(j->jf_junkAttNo))
elog(ERROR, "could not find junk wholerow column");
}
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
}
resultRelInfo->ri_junkFilter = j;
resultRelInfo++;
}
}
else
{
if (operation == CMD_INSERT)
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
ExecCheckPlanOutput(mtstate->resultRelInfo->ri_RelationDesc,
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
subplan->targetlist);
}
}
/*
pgindent run for 9.0
2010-02-26 03:01:40 +01:00
* Set up a tuple table slot for use for trigger output tuples. In a plan
* containing multiple ModifyTable nodes, all can share one such slot, so
* we keep it in the estate.
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
*/
if (estate->es_trig_tuple_slot == NULL)
estate->es_trig_tuple_slot = ExecInitExtraTupleSlot(estate);
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
/*
* Lastly, if this is not the primary (canSetTag) ModifyTable node, add it
* to estate->es_auxmodifytables so that it will be run to completion by
* ExecPostprocessPlan. (It'd actually work fine to add the primary
pgindent run before PG 9.1 beta 1.
2011-04-10 17:42:00 +02:00
* ModifyTable node too, but there's no need.) Note the use of lcons not
* lappend: we need later-initialized ModifyTable nodes to be shut down
* before earlier ones. This ensures that we don't throw away RETURNING
* rows that need to be seen by a later CTE subplan.
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
*/
if (!mtstate->canSetTag)
Fix order of shutdown processing when CTEs contain inter-references. We need ExecutorEnd to run the ModifyTable nodes to completion in reverse order of initialization, not forward order. Easily done by constructing the list back-to-front.
2011-02-26 05:53:34 +01:00
estate->es_auxmodifytables = lcons(mtstate,
estate->es_auxmodifytables);
Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH. This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-26 00:56:23 +01:00
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
return mtstate;
}
/* ----------------------------------------------------------------
* ExecEndModifyTable
*
* Shuts down the plan.
*
* Returns nothing of interest.
* ----------------------------------------------------------------
*/
void
ExecEndModifyTable(ModifyTableState *node)
{
pgindent run for 9.0
2010-02-26 03:01:40 +01:00
int i;
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
/*
* Free the exprcontext
*/
ExecFreeExprContext(&node->ps);
/*
* clean out the tuple table
*/
ExecClearTuple(node->ps.ps_ResultTupleSlot);
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
/*
* Terminate EPQ execution if active
*/
EvalPlanQualEnd(&node->mt_epqstate);
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
/*
* shut down subplans
*/
pgindent run for 9.0
2010-02-26 03:01:40 +01:00
for (i = 0; i < node->mt_nplans; i++)
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
ExecEndNode(node->mt_plans[i]);
}
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
ExecReScanModifyTable(ModifyTableState *node)
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
{
/*
pgindent run for 9.0
2010-02-26 03:01:40 +01:00
* Currently, we don't need to support rescan on ModifyTable nodes. The
* semantics of that would be a bit debatable anyway.
Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c. They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-10 03:43:50 +02:00
*/
elog(ERROR, "ExecReScanModifyTable is not implemented");
}