database/postgres
database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-04-22 23:02:54 +03:00
Code
postgres/src/backend/executor/execMain.c

1406 lines
35 KiB
C
Raw Blame History

/*-------------------------------------------------------------------------
*
* execMain.c--
* top level executor interface routines
*
* INTERFACE ROUTINES
* ExecutorStart()
* ExecutorRun()
* ExecutorEnd()
*
* The old ExecutorMain() has been replaced by ExecutorStart(),
* ExecutorRun() and ExecutorEnd()
*
* These three procedures are the external interfaces to the executor.
* In each case, the query descriptor and the execution state is required
* as arguments
*
* ExecutorStart() must be called at the beginning of any execution of any
* query plan and ExecutorEnd() should always be called at the end of
* execution of a plan.
*
* ExecutorRun accepts 'feature' and 'count' arguments that specify whether
* the plan is to be executed forwards, backwards, and for how many tuples.
*
* Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/executor/execMain.c,v 1.30 1997/11/17 16:41:04 thomas Exp $
*
*-------------------------------------------------------------------------
*/
#include <string.h>
#include "postgres.h"
#include "miscadmin.h"
#include "executor/executor.h"
#include "executor/execdefs.h"
#include "executor/execdebug.h"
#include "executor/nodeIndexscan.h"
#include "utils/builtins.h"
#include "utils/palloc.h"
#include "utils/acl.h"
#include "utils/syscache.h"
#include "parser/parsetree.h" /* rt_fetch() */
#include "storage/bufmgr.h"
#include "storage/lmgr.h"
#include "storage/smgr.h"
#include "commands/async.h"
/* #include "access/localam.h" */
#include "optimizer/var.h"
#include "access/heapam.h"
#include "catalog/heap.h"
#include "commands/trigger.h"
/* decls for local routines only used within this module */
static void
ExecCheckPerms(CmdType operation, int resultRelation, List *rangeTable,
Query *parseTree);
static TupleDesc
InitPlan(CmdType operation, Query *parseTree,
Plan *plan, EState *estate);
static void EndPlan(Plan *plan, EState *estate);
static TupleTableSlot *
ExecutePlan(EState *estate, Plan *plan,
Query *parseTree, CmdType operation,
int numberTuples, ScanDirection direction,
void (*printfunc) ());
static void ExecRetrieve(TupleTableSlot *slot, void (*printfunc) (),
EState *estate);
static void
ExecAppend(TupleTableSlot *slot, ItemPointer tupleid,
EState *estate);
static void
ExecDelete(TupleTableSlot *slot, ItemPointer tupleid,
EState *estate);
static void
ExecReplace(TupleTableSlot *slot, ItemPointer tupleid,
EState *estate, Query *parseTree);
/* end of local decls */
#ifdef QUERY_LIMIT
static int queryLimit = ALL_TUPLES;
#undef ALL_TUPLES
#define ALL_TUPLES queryLimit
int ExecutorLimit(int limit);
int
ExecutorLimit(int limit)
{
return queryLimit = limit;
}
#endif
/* ----------------------------------------------------------------
* ExecutorStart
*
* This routine must be called at the beginning of any execution of any
* query plan
*
* returns (AttrInfo*) which describes the attributes of the tuples to
* be returned by the query.
*
* ----------------------------------------------------------------
*/
TupleDesc
ExecutorStart(QueryDesc *queryDesc, EState *estate)
{
TupleDesc result;
/* sanity checks */
Assert(queryDesc != NULL);
result = InitPlan(queryDesc->operation,
queryDesc->parsetree,
queryDesc->plantree,
estate);
/*
* reset buffer refcount. the current refcounts are saved and will be
* restored when ExecutorEnd is called
*
* this makes sure that when ExecutorRun's are called recursively as for
* postquel functions, the buffers pinned by one ExecutorRun will not
* be unpinned by another ExecutorRun.
*/
BufferRefCountReset(estate->es_refcount);
return result;
}
/* ----------------------------------------------------------------
* ExecutorRun
*
* This is the main routine of the executor module. It accepts
* the query descriptor from the traffic cop and executes the
* query plan.
*
* ExecutorStart must have been called already.
*
* the different features supported are:
* EXEC_RUN: retrieve all tuples in the forward direction
* EXEC_FOR: retrieve 'count' number of tuples in the forward dir
* EXEC_BACK: retrieve 'count' number of tuples in the backward dir
* EXEC_RETONE: return one tuple but don't 'retrieve' it
* used in postquel function processing
*
*
* ----------------------------------------------------------------
*/
TupleTableSlot *
ExecutorRun(QueryDesc *queryDesc, EState *estate, int feature, int count)
{
CmdType operation;
Query *parseTree;
Plan *plan;
TupleTableSlot *result;
CommandDest dest;
void (*destination) ();
/* ----------------
* sanity checks
* ----------------
*/
Assert(queryDesc != NULL);
/* ----------------
* extract information from the query descriptor
* and the query feature.
* ----------------
*/
operation = queryDesc->operation;
parseTree = queryDesc->parsetree;
plan = queryDesc->plantree;
dest = queryDesc->dest;
destination = (void (*) ()) DestToFunction(dest);
estate->es_processed = 0;
estate->es_lastoid = InvalidOid;
#if 0
/*
* It doesn't work in common case (i.g. if function has a aggregate).
* Now we store parameter values before ExecutorStart. - vadim
* 01/22/97
*/
#ifdef INDEXSCAN_PATCH
/*
* If the plan is an index scan and some of the scan key are function
* arguments rescan the indices after the parameter values have been
* stored in the execution state. DZ - 27-8-1996
*/
if ((nodeTag(plan) == T_IndexScan) &&
(((IndexScan *) plan)->indxstate->iss_RuntimeKeyInfo != NULL))
{
ExprContext *econtext;
econtext = ((IndexScan *) plan)->scan.scanstate->cstate.cs_ExprContext;
ExecIndexReScan((IndexScan *) plan, econtext, plan);
}
#endif
#endif
switch (feature)
{
case EXEC_RUN:
result = ExecutePlan(estate,
plan,
parseTree,
operation,
ALL_TUPLES,
ForwardScanDirection,
destination);
break;
case EXEC_FOR:
result = ExecutePlan(estate,
plan,
parseTree,
operation,
count,
ForwardScanDirection,
destination);
break;
/* ----------------
* retrieve next n "backward" tuples
* ----------------
*/
case EXEC_BACK:
result = ExecutePlan(estate,
plan,
parseTree,
operation,
count,
BackwardScanDirection,
destination);
break;
/* ----------------
* return one tuple but don't "retrieve" it.
* (this is used by the rule manager..) -cim 9/14/89
* ----------------
*/
case EXEC_RETONE:
result = ExecutePlan(estate,
plan,
parseTree,
operation,
ONE_TUPLE,
ForwardScanDirection,
destination);
break;
default:
result = NULL;
elog(DEBUG, "ExecutorRun: Unknown feature %d", feature);
break;
}
return result;
}
/* ----------------------------------------------------------------
* ExecutorEnd
*
* This routine must be called at the end of any execution of any
* query plan
*
* returns (AttrInfo*) which describes the attributes of the tuples to
* be returned by the query.
*
* ----------------------------------------------------------------
*/
void
ExecutorEnd(QueryDesc *queryDesc, EState *estate)
{
/* sanity checks */
Assert(queryDesc != NULL);
EndPlan(queryDesc->plantree, estate);
/* restore saved refcounts. */
BufferRefCountRestore(estate->es_refcount);
}
/* ===============================================================
* ===============================================================
static routines follow
* ===============================================================
* ===============================================================
*/
static void
ExecCheckPerms(CmdType operation,
int resultRelation,
List *rangeTable,
Query *parseTree)
{
int i = 1;
Oid relid;
HeapTuple htp;
List *lp;
List *qvars,
*tvars;
int32 ok = 1,
aclcheck_result = -1;
char *opstr;
NameData rname;
char *userName;
#define CHECK(MODE) pg_aclcheck(rname.data, userName, MODE)
userName = GetPgUserName();
foreach(lp, rangeTable)
{
RangeTblEntry *rte = lfirst(lp);
relid = rte->relid;
htp = SearchSysCacheTuple(RELOID,
ObjectIdGetDatum(relid),
0, 0, 0);
if (!HeapTupleIsValid(htp))
elog(WARN, "ExecCheckPerms: bogus RT relid: %d",
relid);
StrNCpy(rname.data,
((Form_pg_class) GETSTRUCT(htp))->relname.data,
NAMEDATALEN);
if (i == resultRelation)
{ /* this is the result relation */
qvars = pull_varnos(parseTree->qual);
tvars = pull_varnos((Node *) parseTree->targetList);
if (intMember(resultRelation, qvars) ||
intMember(resultRelation, tvars))
{
/* result relation is scanned */
ok = ((aclcheck_result = CHECK(ACL_RD)) == ACLCHECK_OK);
opstr = "read";
if (!ok)
break;
}
switch (operation)
{
case CMD_INSERT:
ok = ((aclcheck_result = CHECK(ACL_AP)) == ACLCHECK_OK) ||
((aclcheck_result = CHECK(ACL_WR)) == ACLCHECK_OK);
opstr = "append";
break;
case CMD_NOTIFY: /* what does this mean?? -- jw,
* 1/6/94 */
case CMD_DELETE:
case CMD_UPDATE:
ok = ((aclcheck_result = CHECK(ACL_WR)) == ACLCHECK_OK);
opstr = "write";
break;
default:
elog(WARN, "ExecCheckPerms: bogus operation %d",
operation);
}
}
else
{
/* XXX NOTIFY?? */
ok = ((aclcheck_result = CHECK(ACL_RD)) == ACLCHECK_OK);
opstr = "read";
}
if (!ok)
break;
++i;
}
if (!ok)
{
elog(WARN, "%s: %s", rname.data, aclcheck_error_strings[aclcheck_result]);
}
}
/* ----------------------------------------------------------------
* InitPlan
*
* Initializes the query plan: open files, allocate storage
* and start up the rule manager
* ----------------------------------------------------------------
*/
static TupleDesc
InitPlan(CmdType operation, Query *parseTree, Plan *plan, EState *estate)
{
List *rangeTable;
int resultRelation;
Relation intoRelationDesc;
TupleDesc tupType;
List *targetList;
int len;
/* ----------------
* get information from query descriptor
* ----------------
*/
rangeTable = parseTree->rtable;
resultRelation = parseTree->resultRelation;
/* ----------------
* initialize the node's execution state
* ----------------
*/
estate->es_range_table = rangeTable;
/* ----------------
* initialize the BaseId counter so node base_id's
* are assigned correctly. Someday baseid's will have to
* be stored someplace other than estate because they
* should be unique per query planned.
* ----------------
*/
estate->es_BaseId = 1;
/* ----------------
* initialize result relation stuff
* ----------------
*/
if (resultRelation != 0 && operation != CMD_SELECT)
{
/* ----------------
* if we have a result relation, open it and
* initialize the result relation info stuff.
* ----------------
*/
RelationInfo *resultRelationInfo;
Index resultRelationIndex;
RangeTblEntry *rtentry;
Oid resultRelationOid;
Relation resultRelationDesc;
resultRelationIndex = resultRelation;
rtentry = rt_fetch(resultRelationIndex, rangeTable);
resultRelationOid = rtentry->relid;
resultRelationDesc = heap_open(resultRelationOid);
if (resultRelationDesc->rd_rel->relkind == RELKIND_SEQUENCE)
elog(WARN, "You can't change sequence relation %s",
resultRelationDesc->rd_rel->relname.data);
/*
* Write-lock the result relation right away: if the relation is
* used in a subsequent scan, we won't have to elevate the
* read-lock set by heap_beginscan to a write-lock (needed by
* heap_insert, heap_delete and heap_replace). This will hopefully
* prevent some deadlocks. - 01/24/94
*/
RelationSetLockForWrite(resultRelationDesc);
resultRelationInfo = makeNode(RelationInfo);
resultRelationInfo->ri_RangeTableIndex = resultRelationIndex;
resultRelationInfo->ri_RelationDesc = resultRelationDesc;
resultRelationInfo->ri_NumIndices = 0;
resultRelationInfo->ri_IndexRelationDescs = NULL;
resultRelationInfo->ri_IndexRelationInfo = NULL;
/* ----------------
* open indices on result relation and save descriptors
* in the result relation information..
* ----------------
*/
ExecOpenIndices(resultRelationOid, resultRelationInfo);
estate->es_result_relation_info = resultRelationInfo;
}
else
{
/* ----------------
* if no result relation, then set state appropriately
* ----------------
*/
estate->es_result_relation_info = NULL;
}
#ifndef NO_SECURITY
ExecCheckPerms(operation, resultRelation, rangeTable, parseTree);
#endif
/* ----------------
* initialize the executor "tuple" table.
* ----------------
*/
{
int nSlots = ExecCountSlotsNode(plan);
TupleTable tupleTable = ExecCreateTupleTable(nSlots + 10); /* why add ten? - jolly */
estate->es_tupleTable = tupleTable;
}
/* ----------------
* initialize the private state information for
* all the nodes in the query tree. This opens
* files, allocates storage and leaves us ready
* to start processing tuples..
* ----------------
*/
ExecInitNode(plan, estate, NULL);
/* ----------------
* get the tuple descriptor describing the type
* of tuples to return.. (this is especially important
* if we are creating a relation with "retrieve into")
* ----------------
*/
tupType = ExecGetTupType(plan); /* tuple descriptor */
targetList = plan->targetlist;
len = ExecTargetListLength(targetList); /* number of attributes */
/* ----------------
* now that we have the target list, initialize the junk filter
* if this is a REPLACE or a DELETE query.
* We also init the junk filter if this is an append query
* (there might be some rule lock info there...)
* NOTE: in the future we might want to initialize the junk
* filter for all queries.
* ----------------
*/
if (operation == CMD_UPDATE || operation == CMD_DELETE ||
operation == CMD_INSERT)
{
JunkFilter *j = (JunkFilter *) ExecInitJunkFilter(targetList);
estate->es_junkFilter = j;
}
else
estate->es_junkFilter = NULL;
/* ----------------
* initialize the "into" relation
* ----------------
*/
intoRelationDesc = (Relation) NULL;
if (operation == CMD_SELECT)
{
char *intoName;
char archiveMode;
Oid intoRelationId;
TupleDesc tupdesc;
if (!parseTree->isPortal)
{
/*
* a select into table
*/
if (parseTree->into != NULL)
{
/* ----------------
* create the "into" relation
*
* note: there is currently no way for the user to
* specify the desired archive mode of the
* "into" relation...
* ----------------
*/
intoName = parseTree->into;
archiveMode = 'n';
/*
* have to copy tupType to get rid of constraints
*/
tupdesc = CreateTupleDescCopy(tupType);
/* fixup to prevent zero-length columns in create */
setVarAttrLenForCreateTable(tupdesc, targetList, rangeTable);
intoRelationId = heap_create(intoName,
intoName, /* not used */
archiveMode,
DEFAULT_SMGR,
tupdesc);
#ifdef NOT_USED /* it's copy ... */
resetVarAttrLenForCreateTable(tupdesc);
#endif
FreeTupleDesc(tupdesc);
/* ----------------
* XXX rather than having to call setheapoverride(true)
* and then back to false, we should change the
* arguments to heap_open() instead..
* ----------------
*/
setheapoverride(true);
intoRelationDesc = heap_open(intoRelationId);
setheapoverride(false);
}
}
}
estate->es_into_relation_descriptor = intoRelationDesc;
/* ----------------
* return the type information..
* ----------------
*/
/*
attinfo = (AttrInfo *)palloc(sizeof(AttrInfo));
attinfo->numAttr = len;
attinfo->attrs = tupType->attrs;
*/
return tupType;
}
/* ----------------------------------------------------------------
* EndPlan
*
* Cleans up the query plan -- closes files and free up storages
* ----------------------------------------------------------------
*/
static void
EndPlan(Plan *plan, EState *estate)
{
RelationInfo *resultRelationInfo;
Relation intoRelationDesc;
/* ----------------
* get information from state
* ----------------
*/
resultRelationInfo = estate->es_result_relation_info;
intoRelationDesc = estate->es_into_relation_descriptor;
/* ----------------
* shut down the query
* ----------------
*/
ExecEndNode(plan, plan);
/* ----------------
* destroy the executor "tuple" table.
* ----------------
*/
{
TupleTable tupleTable = (TupleTable) estate->es_tupleTable;
ExecDestroyTupleTable(tupleTable, true); /* was missing last arg */
estate->es_tupleTable = NULL;
}
/* ----------------
* close the result relations if necessary
* ----------------
*/
if (resultRelationInfo != NULL)
{
Relation resultRelationDesc;
resultRelationDesc = resultRelationInfo->ri_RelationDesc;
heap_close(resultRelationDesc);
/* ----------------
* close indices on the result relation
* ----------------
*/
ExecCloseIndices(resultRelationInfo);
}
/* ----------------
* close the "into" relation if necessary
* ----------------
*/
if (intoRelationDesc != NULL)
{
heap_close(intoRelationDesc);
}
}
/* ----------------------------------------------------------------
* ExecutePlan
*
* processes the query plan to retrieve 'tupleCount' tuples in the
* direction specified.
* Retrieves all tuples if tupleCount is 0
*
* result is either a slot containing a tuple in the case
* of a RETRIEVE or NULL otherwise.
*
* ----------------------------------------------------------------
*/
/* the ctid attribute is a 'junk' attribute that is removed before the
user can see it*/
static TupleTableSlot *
ExecutePlan(EState *estate,
Plan *plan,
Query *parseTree,
CmdType operation,
int numberTuples,
ScanDirection direction,
void (*printfunc) ())
{
JunkFilter *junkfilter;
TupleTableSlot *slot;
ItemPointer tupleid = NULL;
ItemPointerData tuple_ctid;
int current_tuple_count;
TupleTableSlot *result;
/* ----------------
* initialize local variables
* ----------------
*/
slot = NULL;
current_tuple_count = 0;
result = NULL;
/* ----------------
* Set the direction.
* ----------------
*/
estate->es_direction = direction;
/* ----------------
* Loop until we've processed the proper number
* of tuples from the plan..
* ----------------
*/
for (;;)
{
if (operation != CMD_NOTIFY)
{
/* ----------------
* Execute the plan and obtain a tuple
* ----------------
*/
/* at the top level, the parent of a plan (2nd arg) is itself */
slot = ExecProcNode(plan, plan);
/* ----------------
* if the tuple is null, then we assume
* there is nothing more to process so
* we just return null...
* ----------------
*/
if (TupIsNull(slot))
{
result = NULL;
break;
}
}
/* ----------------
* if we have a junk filter, then project a new
* tuple with the junk removed.
*
* Store this new "clean" tuple in the place of the
* original tuple.
*
* Also, extract all the junk ifnormation we need.
* ----------------
*/
if ((junkfilter = estate->es_junkFilter) != (JunkFilter *) NULL)
{
Datum datum;
/* NameData attrName; */
HeapTuple newTuple;
bool isNull;
/* ---------------
* extract the 'ctid' junk attribute.
* ---------------
*/
if (operation == CMD_UPDATE || operation == CMD_DELETE)
{
if (!ExecGetJunkAttribute(junkfilter,
slot,
"ctid",
&datum,
&isNull))
elog(WARN, "ExecutePlan: NO (junk) `ctid' was found!");
if (isNull)
elog(WARN, "ExecutePlan: (junk) `ctid' is NULL!");
tupleid = (ItemPointer) DatumGetPointer(datum);
tuple_ctid = *tupleid; /* make sure we don't free the
* ctid!! */
tupleid = &tuple_ctid;
}
/* ---------------
* Finally create a new "clean" tuple with all junk attributes
* removed
* ---------------
*/
newTuple = ExecRemoveJunk(junkfilter, slot);
slot = ExecStoreTuple(newTuple, /* tuple to store */
slot, /* destination slot */
InvalidBuffer, /* this tuple has no
* buffer */
true); /* tuple should be pfreed */
} /* if (junkfilter... */
/* ----------------
* now that we have a tuple, do the appropriate thing
* with it.. either return it to the user, add
* it to a relation someplace, delete it from a
* relation, or modify some of it's attributes.
* ----------------
*/
switch (operation)
{
case CMD_SELECT:
ExecRetrieve(slot, /* slot containing tuple */
printfunc, /* print function */
estate); /* */
result = slot;
break;
case CMD_INSERT:
ExecAppend(slot, tupleid, estate);
result = NULL;
break;
case CMD_DELETE:
ExecDelete(slot, tupleid, estate);
result = NULL;
break;
case CMD_UPDATE:
ExecReplace(slot, tupleid, estate, parseTree);
result = NULL;
break;
/*
* Total hack. I'm ignoring any accessor functions for
* Relation, RelationTupleForm, NameData. Assuming that
* NameData.data has offset 0.
*/
case CMD_NOTIFY:
{
RelationInfo *rInfo = estate->es_result_relation_info;
Relation rDesc = rInfo->ri_RelationDesc;
Async_Notify(rDesc->rd_rel->relname.data);
result = NULL;
current_tuple_count = 0;
numberTuples = 1;
elog(DEBUG, "ExecNotify %s", &rDesc->rd_rel->relname);
}
break;
default:
elog(DEBUG, "ExecutePlan: unknown operation in queryDesc");
result = NULL;
break;
}
/* ----------------
* check our tuple count.. if we've returned the
* proper number then return, else loop again and
* process more tuples..
* ----------------
*/
current_tuple_count += 1;
if (numberTuples == current_tuple_count)
break;
}
/* ----------------
* here, result is either a slot containing a tuple in the case
* of a RETRIEVE or NULL otherwise.
* ----------------
*/
return result;
}
/* ----------------------------------------------------------------
* ExecRetrieve
*
* RETRIEVEs are easy.. we just pass the tuple to the appropriate
* print function. The only complexity is when we do a
* "retrieve into", in which case we insert the tuple into
* the appropriate relation (note: this is a newly created relation
* so we don't need to worry about indices or locks.)
* ----------------------------------------------------------------
*/
static void
ExecRetrieve(TupleTableSlot *slot,
void (*printfunc) (),
EState *estate)
{
HeapTuple tuple;
TupleDesc attrtype;
/* ----------------
* get the heap tuple out of the tuple table slot
* ----------------
*/
tuple = slot->val;
attrtype = slot->ttc_tupleDescriptor;
/* ----------------
* insert the tuple into the "into relation"
* ----------------
*/
if (estate->es_into_relation_descriptor != NULL)
{
heap_insert(estate->es_into_relation_descriptor, tuple);
IncrAppended();
}
/* ----------------
* send the tuple to the front end (or the screen)
* ----------------
*/
(*printfunc) (tuple, attrtype);
IncrRetrieved();
(estate->es_processed)++;
}
/* ----------------------------------------------------------------
* ExecAppend
*
* APPENDs are trickier.. we have to insert the tuple into
* the base relation and insert appropriate tuples into the
* index relations.
* ----------------------------------------------------------------
*/
static void
ExecAppend(TupleTableSlot *slot,
ItemPointer tupleid,
EState *estate)
{
HeapTuple tuple;
RelationInfo *resultRelationInfo;
Relation resultRelationDesc;
int numIndices;
Oid newId;
/* ----------------
* get the heap tuple out of the tuple table slot
* ----------------
*/
tuple = slot->val;
/* ----------------
* get information on the result relation
* ----------------
*/
resultRelationInfo = estate->es_result_relation_info;
resultRelationDesc = resultRelationInfo->ri_RelationDesc;
/* ----------------
* have to add code to preform unique checking here.
* cim -12/1/89
* ----------------
*/
/* BEFORE ROW INSERT Triggers */
if (resultRelationDesc->trigdesc &&
resultRelationDesc->trigdesc->n_before_row[TRIGGER_EVENT_INSERT] > 0)
{
HeapTuple newtuple;
newtuple = ExecBRInsertTriggers(resultRelationDesc, tuple);
if (newtuple == NULL) /* "do nothing" */
return;
if (newtuple != tuple) /* modified by Trigger(s) */
{
Assert(slot->ttc_shouldFree);
pfree(tuple);
slot->val = tuple = newtuple;
}
}
/* ----------------
* Check the constraints of a tuple
* ----------------
*/
if (resultRelationDesc->rd_att->constr)
{
HeapTuple newtuple;
newtuple = ExecConstraints("ExecAppend", resultRelationDesc, tuple);
if (newtuple != tuple) /* modified by DEFAULT */
{
Assert(slot->ttc_shouldFree);
pfree(tuple);
slot->val = tuple = newtuple;
}
}
/* ----------------
* insert the tuple
* ----------------
*/
newId = heap_insert(resultRelationDesc, /* relation desc */
tuple); /* heap tuple */
IncrAppended();
/* ----------------
* process indices
*
* Note: heap_insert adds a new tuple to a relation. As a side
* effect, the tupleid of the new tuple is placed in the new
* tuple's t_ctid field.
* ----------------
*/
numIndices = resultRelationInfo->ri_NumIndices;
if (numIndices > 0)
{
ExecInsertIndexTuples(slot, &(tuple->t_ctid), estate, false);
}
(estate->es_processed)++;
estate->es_lastoid = newId;
/* AFTER ROW INSERT Triggers */
if (resultRelationDesc->trigdesc &&
resultRelationDesc->trigdesc->n_after_row[TRIGGER_EVENT_INSERT] > 0)
ExecARInsertTriggers(resultRelationDesc, tuple);
}
/* ----------------------------------------------------------------
* ExecDelete
*
* DELETE is like append, we delete the tuple and its
* index tuples.
* ----------------------------------------------------------------
*/
static void
ExecDelete(TupleTableSlot *slot,
ItemPointer tupleid,
EState *estate)
{
RelationInfo *resultRelationInfo;
Relation resultRelationDesc;
/* ----------------
* get the result relation information
* ----------------
*/
resultRelationInfo = estate->es_result_relation_info;
resultRelationDesc = resultRelationInfo->ri_RelationDesc;
/* BEFORE ROW DELETE Triggers */
if (resultRelationDesc->trigdesc &&
resultRelationDesc->trigdesc->n_before_row[TRIGGER_EVENT_DELETE] > 0)
{
bool dodelete;
dodelete = ExecBRDeleteTriggers(resultRelationDesc, tupleid);
if (!dodelete) /* "do nothing" */
return;
}
/* ----------------
* delete the tuple
* ----------------
*/
if (heap_delete(resultRelationDesc, /* relation desc */
tupleid)) /* item pointer to tuple */
return;
IncrDeleted();
(estate->es_processed)++;
/* ----------------
* 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 the vacuum daemon automatically
* opens an index scan and deletes index tuples
* when it finds deleted heap tuples. -cim 9/27/89
* ----------------
*/
/* AFTER ROW DELETE Triggers */
if (resultRelationDesc->trigdesc &&
resultRelationDesc->trigdesc->n_after_row[TRIGGER_EVENT_DELETE] > 0)
ExecARDeleteTriggers(resultRelationDesc, tupleid);
}
/* ----------------------------------------------------------------
* ExecReplace
*
* note: we can't run replace queries with transactions
* off because replaces are actually appends and our
* scan will mistakenly loop forever, replacing the tuple
* it just appended.. This should be fixed but until it
* is, we don't want to get stuck in an infinite loop
* which corrupts your database..
* ----------------------------------------------------------------
*/
static void
ExecReplace(TupleTableSlot *slot,
ItemPointer tupleid,
EState *estate,
Query *parseTree)
{
HeapTuple tuple;
RelationInfo *resultRelationInfo;
Relation resultRelationDesc;
int numIndices;
/* ----------------
* abort the operation if not running transactions
* ----------------
*/
if (IsBootstrapProcessingMode())
{
elog(DEBUG, "ExecReplace: replace can't run without transactions");
return;
}
/* ----------------
* get the heap tuple out of the tuple table slot
* ----------------
*/
tuple = slot->val;
/* ----------------
* get the result relation information
* ----------------
*/
resultRelationInfo = estate->es_result_relation_info;
resultRelationDesc = resultRelationInfo->ri_RelationDesc;
/* ----------------
* have to add code to preform unique checking here.
* in the event of unique tuples, this becomes a deletion
* of the original tuple affected by the replace.
* cim -12/1/89
* ----------------
*/
/* BEFORE ROW UPDATE Triggers */
if (resultRelationDesc->trigdesc &&
resultRelationDesc->trigdesc->n_before_row[TRIGGER_EVENT_UPDATE] > 0)
{
HeapTuple newtuple;
newtuple = ExecBRUpdateTriggers(resultRelationDesc, tupleid, tuple);
if (newtuple == NULL) /* "do nothing" */
return;
if (newtuple != tuple) /* modified by Trigger(s) */
{
Assert(slot->ttc_shouldFree);
pfree(tuple);
slot->val = tuple = newtuple;
}
}
/* ----------------
* Check the constraints of a tuple
* ----------------
*/
if (resultRelationDesc->rd_att->constr)
{
HeapTuple newtuple;
newtuple = ExecConstraints("ExecReplace", resultRelationDesc, tuple);
if (newtuple != tuple) /* modified by DEFAULT */
{
Assert(slot->ttc_shouldFree);
pfree(tuple);
slot->val = tuple = newtuple;
}
}
/* ----------------
* replace the heap tuple
*
* Don't want to continue if our heap_replace didn't actually
* do a replace. This would be the case if heap_replace
* detected a non-functional update. -kw 12/30/93
* ----------------
*/
if (heap_replace(resultRelationDesc, /* relation desc */
tupleid, /* item ptr of tuple to replace */
tuple))
{ /* replacement heap tuple */
return;
}
IncrReplaced();
(estate->es_processed)++;
/* ----------------
* Note: instead of having to update the old index tuples
* associated with the heap tuple, all we do is form
* and insert new index tuples.. This is because
* replaces are actually deletes and inserts and
* index tuple deletion is done automagically by
* the vaccuum deamon.. All we do is insert new
* index tuples. -cim 9/27/89
* ----------------
*/
/* ----------------
* process indices
*
* heap_replace updates a tuple in the base relation by invalidating
* it and then appending a new tuple to the relation. As a side
* effect, the tupleid of the new tuple is placed in the new
* tuple's t_ctid field. So we now insert index tuples using
* the new tupleid stored there.
* ----------------
*/
numIndices = resultRelationInfo->ri_NumIndices;
if (numIndices > 0)
{
ExecInsertIndexTuples(slot, &(tuple->t_ctid), estate, true);
}
/* AFTER ROW UPDATE Triggers */
if (resultRelationDesc->trigdesc &&
resultRelationDesc->trigdesc->n_after_row[TRIGGER_EVENT_UPDATE] > 0)
ExecARUpdateTriggers(resultRelationDesc, tupleid, tuple);
}
#if 0
static HeapTuple
ExecAttrDefault(Relation rel, HeapTuple tuple)
{
int ndef = rel->rd_att->constr->num_defval;
AttrDefault *attrdef = rel->rd_att->constr->defval;
ExprContext *econtext = makeNode(ExprContext);
HeapTuple newtuple;
Node *expr;
bool isnull;
bool isdone;
Datum val;
Datum *replValue = NULL;
char *replNull = NULL;
char *repl = NULL;
int i;
econtext->ecxt_scantuple = NULL; /* scan tuple slot */
econtext->ecxt_innertuple = NULL; /* inner tuple slot */
econtext->ecxt_outertuple = NULL; /* outer tuple slot */
econtext->ecxt_relation = NULL; /* relation */
econtext->ecxt_relid = 0; /* relid */
econtext->ecxt_param_list_info = NULL; /* param list info */
econtext->ecxt_range_table = NULL; /* range table */
for (i = 0; i < ndef; i++)
{
if (!heap_attisnull(tuple, attrdef[i].adnum))
continue;
expr = (Node *) stringToNode(attrdef[i].adbin);
val = ExecEvalExpr(expr, econtext, &isnull, &isdone);
pfree(expr);
if (isnull)
continue;
if (repl == NULL)
{
repl = (char *) palloc(rel->rd_att->natts * sizeof(char));
replNull = (char *) palloc(rel->rd_att->natts * sizeof(char));
replValue = (Datum *) palloc(rel->rd_att->natts * sizeof(Datum));
MemSet(repl, ' ', rel->rd_att->natts * sizeof(char));
}
repl[attrdef[i].adnum - 1] = 'r';
replNull[attrdef[i].adnum - 1] = ' ';
replValue[attrdef[i].adnum - 1] = val;
}
pfree(econtext);
if (repl == NULL)
return (tuple);
newtuple = heap_modifytuple(tuple, InvalidBuffer, rel, replValue, replNull, repl);
pfree(repl);
pfree(replNull);
pfree(replValue);
return (newtuple);
}
#endif
static char *
ExecRelCheck(Relation rel, HeapTuple tuple)
{
int ncheck = rel->rd_att->constr->num_check;
ConstrCheck *check = rel->rd_att->constr->check;
ExprContext *econtext = makeNode(ExprContext);
TupleTableSlot *slot = makeNode(TupleTableSlot);
RangeTblEntry *rte = makeNode(RangeTblEntry);
List *rtlist;
List *qual;
bool res;
int i;
slot->val = tuple;
slot->ttc_shouldFree = false;
slot->ttc_descIsNew = true;
slot->ttc_tupleDescriptor = rel->rd_att;
slot->ttc_buffer = InvalidBuffer;
slot->ttc_whichplan = -1;
rte->relname = nameout(&(rel->rd_rel->relname));
rte->timeRange = NULL;
rte->refname = rte->relname;
rte->relid = rel->rd_id;
rte->inh = false;
rte->archive = false;
rte->inFromCl = true;
rte->timeQual = NULL;
rtlist = lcons(rte, NIL);
econtext->ecxt_scantuple = slot; /* scan tuple slot */
econtext->ecxt_innertuple = NULL; /* inner tuple slot */
econtext->ecxt_outertuple = NULL; /* outer tuple slot */
econtext->ecxt_relation = rel; /* relation */
econtext->ecxt_relid = 0; /* relid */
econtext->ecxt_param_list_info = NULL; /* param list info */
econtext->ecxt_range_table = rtlist; /* range table */
for (i = 0; i < ncheck; i++)
{
qual = (List *) stringToNode(check[i].ccbin);
res = ExecQual(qual, econtext);
pfree(qual);
if (!res)
return (check[i].ccname);
}
pfree(slot);
pfree(rte->relname);
pfree(rte);
pfree(rtlist);
pfree(econtext);
return ((char *) NULL);
}
HeapTuple
ExecConstraints(char *caller, Relation rel, HeapTuple tuple)
{
HeapTuple newtuple = tuple;
Assert(rel->rd_att->constr);
#if 0
if (rel->rd_att->constr->num_defval > 0)
newtuple = tuple = ExecAttrDefault(rel, tuple);
#endif
if (rel->rd_att->constr->has_not_null)
{
int attrChk;
for (attrChk = 1; attrChk <= rel->rd_att->natts; attrChk++)
{
if (rel->rd_att->attrs[attrChk - 1]->attnotnull && heap_attisnull(tuple, attrChk))
elog(WARN, "%s: Fail to add null value in not null attribute %s",
caller, rel->rd_att->attrs[attrChk - 1]->attname.data);
}
}
if (rel->rd_att->constr->num_check > 0)
{
char *failed;
if ((failed = ExecRelCheck(rel, tuple)) != NULL)
elog(WARN, "%s: rejected due to CHECK constraint %s", caller, failed);
}
return (newtuple);
}
View Git Blame Copy Permalink