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Make ALTER TABLE RENAME update foreign-key trigger arguments correctly.

Browse Source 
Brent Verner, with review and kibitzing from Tom Lane.
REL7_2_STABLE
Tom Lane 24 years ago
parent 8bfc437301
commit f14fdad858
3 changed files with 304 additions and 13 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
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  1. 284
      src/backend/commands/rename.c
  2. 12
      src/backend/utils/adt/ri_triggers.c
  3. 21
      src/include/commands/trigger.h

284
src/backend/commands/rename.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/commands/Attic/rename.c,v 1.61 2001/11/05 17:46:24 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/commands/Attic/rename.c,v 1.62 2001/11/12 00:46:36 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -16,25 +16,43 @@
#include <errno.h>
#include "access/genam.h"
#include "access/heapam.h"
#include "access/itup.h"
#include "catalog/catname.h"
#include "catalog/pg_index.h"
#include "catalog/pg_trigger.h"
#include "catalog/pg_type.h"
#include "catalog/heap.h"
#include "catalog/indexing.h"
#include "catalog/catalog.h"
#include "commands/rename.h"
#include "commands/trigger.h"
#include "miscadmin.h"
#include "storage/smgr.h"
#include "optimizer/prep.h"
#include "rewrite/rewriteDefine.h"
#include "rewrite/rewriteSupport.h"
#include "utils/acl.h"
#include "utils/builtins.h"
#include "utils/fmgroids.h"
#include "utils/relcache.h"
#include "utils/syscache.h"
#include "utils/temprel.h"
#define RI_TRIGGER_PK 1 /* is a trigger on the PK relation */
#define RI_TRIGGER_FK 2 /* is a trigger on the FK relation */
#define RI_TRIGGER_NONE 0 /* is not an RI trigger function */
static int ri_trigger_type(Oid tgfoid);
static void update_ri_trigger_args(Oid relid,
const char* oldname,
const char* newname,
bool fk_scan,
bool update_relname);
/*
* renameatt - changes the name of a attribute in a relation
*
@ -226,6 +244,22 @@ renameatt(char *relname,
freeList(indexoidlist);
heap_close(attrelation, RowExclusiveLock);
/*
* Update att name in any RI triggers associated with the relation.
*/
if (targetrelation->rd_rel->reltriggers > 0)
{
/* update tgargs column reference where att is primary key */
update_ri_trigger_args(RelationGetRelid(targetrelation),
oldattname, newattname,
false, false);
/* update tgargs column reference where att is foreign key */
update_ri_trigger_args(RelationGetRelid(targetrelation),
oldattname, newattname,
true, false);
}
heap_close(targetrelation, NoLock); /* close rel but keep lock! */
}
@ -240,6 +274,7 @@ renamerel(const char *oldrelname, const char *newrelname)
HeapTuple reltup;
Oid reloid;
char relkind;
bool relhastriggers;
Relation irelations[Num_pg_class_indices];
if (!allowSystemTableMods && IsSystemRelationName(oldrelname))
@ -265,6 +300,7 @@ renamerel(const char *oldrelname, const char *newrelname)
reloid = RelationGetRelid(targetrelation);
relkind = targetrelation->rd_rel->relkind;
relhastriggers = (targetrelation->rd_rel->reltriggers > 0);
/*
* Close rel, but keep exclusive lock!
@ -331,4 +367,250 @@ renamerel(const char *oldrelname, const char *newrelname)
newrulename = MakeRetrieveViewRuleName(newrelname);
RenameRewriteRule(oldrulename, newrulename);
}
/*
* Update rel name in any RI triggers associated with the relation.
*/
if (relhastriggers)
{
/* update tgargs where relname is primary key */
update_ri_trigger_args(reloid,
oldrelname, newrelname,
false, true);
/* update tgargs where relname is foreign key */
update_ri_trigger_args(reloid,
oldrelname, newrelname,
true, true);
}
}
/*
* Given a trigger function OID, determine whether it is an RI trigger,
* and if so whether it is attached to PK or FK relation.
*
* XXX this probably doesn't belong here; should be exported by
* ri_triggers.c
*/
static int
ri_trigger_type(Oid tgfoid)
{
switch (tgfoid)
{
case F_RI_FKEY_CASCADE_DEL:
case F_RI_FKEY_CASCADE_UPD:
case F_RI_FKEY_RESTRICT_DEL:
case F_RI_FKEY_RESTRICT_UPD:
case F_RI_FKEY_SETNULL_DEL:
case F_RI_FKEY_SETNULL_UPD:
case F_RI_FKEY_SETDEFAULT_DEL:
case F_RI_FKEY_SETDEFAULT_UPD:
case F_RI_FKEY_NOACTION_DEL:
case F_RI_FKEY_NOACTION_UPD:
return RI_TRIGGER_PK;
case F_RI_FKEY_CHECK_INS:
case F_RI_FKEY_CHECK_UPD:
return RI_TRIGGER_FK;
}
return RI_TRIGGER_NONE;
}
/*
* Scan pg_trigger for RI triggers that are on the specified relation
* (if fk_scan is false) or have it as the tgconstrrel (if fk_scan
* is true). Update RI trigger args fields matching oldname to contain
* newname instead. If update_relname is true, examine the relname
* fields; otherwise examine the attname fields.
*/
static void
update_ri_trigger_args(Oid relid,
const char* oldname,
const char* newname,
bool fk_scan,
bool update_relname)
{
Relation tgrel;
Relation irel;
ScanKeyData skey[1];
IndexScanDesc idxtgscan;
RetrieveIndexResult idxres;
Datum values[Natts_pg_trigger];
char nulls[Natts_pg_trigger];
char replaces[Natts_pg_trigger];
tgrel = heap_openr(TriggerRelationName, RowExclusiveLock);
if (fk_scan)
irel = index_openr(TriggerConstrRelidIndex);
else
irel = index_openr(TriggerRelidIndex);
ScanKeyEntryInitialize(&skey[0], 0x0,
1, /* always column 1 of index */
F_OIDEQ,
ObjectIdGetDatum(relid));
idxtgscan = index_beginscan(irel, false, 1, skey);
while ((idxres = index_getnext(idxtgscan, ForwardScanDirection)) != NULL)
{
HeapTupleData tupledata;
Buffer buffer;
HeapTuple tuple;
Form_pg_trigger pg_trigger;
bytea* val;
bytea* newtgargs;
bool isnull;
int tg_type;
bool examine_pk;
bool changed;
int tgnargs;
int i;
int newlen;
const char *arga[RI_MAX_ARGUMENTS];
const char *argp;
tupledata.t_self = idxres->heap_iptr;
heap_fetch(tgrel, SnapshotNow, &tupledata, &buffer, idxtgscan);
pfree(idxres);
if (!tupledata.t_data)
continue;
tuple = &tupledata;
pg_trigger = (Form_pg_trigger) GETSTRUCT(tuple);
tg_type = ri_trigger_type(pg_trigger->tgfoid);
if (tg_type == RI_TRIGGER_NONE)
{
/* Not an RI trigger, forget it */
ReleaseBuffer(buffer);
continue;
}
/*
* It is an RI trigger, so parse the tgargs bytea.
*
* NB: we assume the field will never be compressed or moved
* out of line; so does trigger.c ...
*/
tgnargs = pg_trigger->tgnargs;
val = (bytea *) fastgetattr(tuple,
Anum_pg_trigger_tgargs,
tgrel->rd_att, &isnull);
if (isnull || tgnargs < RI_FIRST_ATTNAME_ARGNO ||
tgnargs > RI_MAX_ARGUMENTS)
{
/* This probably shouldn't happen, but ignore busted triggers */
ReleaseBuffer(buffer);
continue;
}
argp = (const char *) VARDATA(val);
for (i = 0; i < tgnargs; i++)
{
arga[i] = argp;
argp += strlen(argp)+1;
}
/*
* Figure out which item(s) to look at. If the trigger is
* primary-key type and attached to my rel, I should look at
* the PK fields; if it is foreign-key type and attached to my
* rel, I should look at the FK fields. But the opposite rule
* holds when examining triggers found by tgconstrrel search.
*/
examine_pk = (tg_type == RI_TRIGGER_PK) == (!fk_scan);
changed = false;
if (update_relname)
{
/* Change the relname if needed */
i = examine_pk ? RI_PK_RELNAME_ARGNO : RI_FK_RELNAME_ARGNO;
if (strcmp(arga[i], oldname) == 0)
{
arga[i] = newname;
changed = true;
}
}
else
{
/* Change attname(s) if needed */
i = examine_pk ? RI_FIRST_ATTNAME_ARGNO + RI_KEYPAIR_PK_IDX :
RI_FIRST_ATTNAME_ARGNO + RI_KEYPAIR_FK_IDX;
for (; i < tgnargs; i += 2)
{
if (strcmp(arga[i], oldname) == 0)
{
arga[i] = newname;
changed = true;
}
}
}
if (!changed)
{
/* Don't need to update this tuple */
ReleaseBuffer(buffer);
continue;
}
/*
* Construct modified tgargs bytea.
*/
newlen = VARHDRSZ;
for (i = 0; i < tgnargs; i++)
newlen += strlen(arga[i]) + 1;
newtgargs = (bytea *) palloc(newlen);
VARATT_SIZEP(newtgargs) = newlen;
newlen = VARHDRSZ;
for (i = 0; i < tgnargs; i++)
{
strcpy(((char *) newtgargs) + newlen, arga[i]);
newlen += strlen(arga[i]) + 1;
}
/*
* Build modified tuple.
*/
for (i = 0; i < Natts_pg_trigger; i++)
{
values[i] = (Datum) 0;
replaces[i] = ' ';
nulls[i] = ' ';
}
values[Anum_pg_trigger_tgargs - 1] = PointerGetDatum(newtgargs);
replaces[Anum_pg_trigger_tgargs - 1] = 'r';
tuple = heap_modifytuple(tuple, tgrel, values, nulls, replaces);
/*
* Now we can release hold on original tuple.
*/
ReleaseBuffer(buffer);
/*
* Update pg_trigger and its indexes
*/
simple_heap_update(tgrel, &tuple->t_self, tuple);
{
Relation irelations[Num_pg_attr_indices];
CatalogOpenIndices(Num_pg_trigger_indices, Name_pg_trigger_indices, irelations);
CatalogIndexInsert(irelations, Num_pg_trigger_indices, tgrel, tuple);
CatalogCloseIndices(Num_pg_trigger_indices, irelations);
}
/* free up our scratch memory */
pfree(newtgargs);
heap_freetuple(tuple);
}
index_endscan(idxtgscan);
index_close(irel);
heap_close(tgrel, RowExclusiveLock);
/*
* Increment cmd counter to make updates visible; this is needed
* in case the same tuple has to be updated again by next pass
* (can happen in case of a self-referential FK relationship).
*/
CommandCounterIncrement();
}

12
src/backend/utils/adt/ri_triggers.c
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@ -18,7 +18,7 @@
* Portions Copyright (c) 2000-2001, PostgreSQL Global Development Group
* Copyright 1999 Jan Wieck
*
* $Header: /cvsroot/pgsql/src/backend/utils/adt/ri_triggers.c,v 1.29 2001/10/25 05:49:45 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/utils/adt/ri_triggers.c,v 1.30 2001/11/12 00:46:36 tgl Exp $
*
* ----------
*/
@ -43,16 +43,6 @@
* Local definitions
* ----------
*/
#define RI_CONSTRAINT_NAME_ARGNO 0
#define RI_FK_RELNAME_ARGNO 1
#define RI_PK_RELNAME_ARGNO 2
#define RI_MATCH_TYPE_ARGNO 3
#define RI_FIRST_ATTNAME_ARGNO 4
#define RI_MAX_NUMKEYS 16
#define RI_MAX_ARGUMENTS (RI_FIRST_ATTNAME_ARGNO + (RI_MAX_NUMKEYS * 2))
#define RI_KEYPAIR_FK_IDX 0
#define RI_KEYPAIR_PK_IDX 1
#define RI_INIT_QUERYHASHSIZE 128
#define RI_INIT_OPREQHASHSIZE 128

21
src/include/commands/trigger.h
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@ -6,7 +6,7 @@
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: trigger.h,v 1.30 2001/11/05 17:46:33 momjian Exp $
* $Id: trigger.h,v 1.31 2001/11/12 00:46:36 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -78,6 +78,25 @@ typedef struct TriggerData
#define TRIGGER_FIRED_AFTER(event) \
(!TRIGGER_FIRED_BEFORE (event))
/*
* RI trigger function arguments are stored in pg_trigger.tgargs bytea
*
* constrname\0fkrel\0pkrel\0matchtype\0fkatt\0pkatt\0fkatt\0pkatt\0...
*
* There are one or more pairs of fkatt/pkatt names.
*/
#define RI_CONSTRAINT_NAME_ARGNO 0
#define RI_FK_RELNAME_ARGNO 1
#define RI_PK_RELNAME_ARGNO 2
#define RI_MATCH_TYPE_ARGNO 3
#define RI_FIRST_ATTNAME_ARGNO 4 /* first attname pair starts here */
#define RI_KEYPAIR_FK_IDX 0
#define RI_KEYPAIR_PK_IDX 1
#define RI_MAX_NUMKEYS INDEX_MAX_KEYS
#define RI_MAX_ARGUMENTS (RI_FIRST_ATTNAME_ARGNO + (RI_MAX_NUMKEYS * 2))
extern void CreateTrigger(CreateTrigStmt *stmt);
extern void DropTrigger(DropTrigStmt *stmt);

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