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Add a RESTART (without parameter) option to ALTER SEQUENCE, allowing a

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sequence to be reset to its original starting value.  This requires adding the
original start value to the set of parameters (columns) of a sequence object,
which is a user-visible change with potential compatibility implications;
it also forces initdb.

Also add hopefully-SQL-compatible RESTART/CONTINUE IDENTITY options to
TRUNCATE TABLE.  RESTART IDENTITY executes ALTER SEQUENCE RESTART for all
sequences "owned by" any of the truncated relations.  CONTINUE IDENTITY is
a no-op option.

Zoltan Boszormenyi
This commit is contained in:
Tom Lane
2008-05-16 23:36:05 +00:00
parent 8a2f5d221b
commit 10a3471bed
18 changed files with 513 additions and 106 deletions
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129
src/backend/commands/sequence.c
View File

@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/commands/sequence.c,v 1.150 2008/05/12 00:00:47 alvherre Exp $
* $PostgreSQL: pgsql/src/backend/commands/sequence.c,v 1.151 2008/05/16 23:36:04 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -91,7 +91,7 @@ static Relation open_share_lock(SeqTable seq);
static void init_sequence(Oid relid, SeqTable *p_elm, Relation *p_rel);
static Form_pg_sequence read_info(SeqTable elm, Relation rel, Buffer *buf);
static void init_params(List *options, bool isInit,
Form_pg_sequence new, List **owned_by);
Form_pg_sequence new, Form_pg_sequence old, List **owned_by);
static void do_setval(Oid relid, int64 next, bool iscalled);
static void process_owned_by(Relation seqrel, List *owned_by);
@@ -119,10 +119,10 @@ DefineSequence(CreateSeqStmt *seq)
NameData name;
/* Check and set all option values */
init_params(seq->options, true, &new, &owned_by);
init_params(seq->options, true, &new, NULL, &owned_by);
/*
* Create relation (and fill *null & *value)
* Create relation (and fill value[] and null[] for the tuple)
*/
stmt->tableElts = NIL;
for (i = SEQ_COL_FIRSTCOL; i <= SEQ_COL_LASTCOL; i++)
@@ -151,6 +151,11 @@ DefineSequence(CreateSeqStmt *seq)
coldef->colname = "last_value";
value[i - 1] = Int64GetDatumFast(new.last_value);
break;
case SEQ_COL_STARTVAL:
coldef->typename = makeTypeNameFromOid(INT8OID, -1);
coldef->colname = "start_value";
value[i - 1] = Int64GetDatumFast(new.start_value);
break;
case SEQ_COL_INCBY:
coldef->typename = makeTypeNameFromOid(INT8OID, -1);
coldef->colname = "increment_by";
@@ -314,6 +319,29 @@ void
AlterSequence(AlterSeqStmt *stmt)
{
Oid relid;
/* find sequence */
relid = RangeVarGetRelid(stmt->sequence, false);
/* allow ALTER to sequence owner only */
/* if you change this, see also callers of AlterSequenceInternal! */
if (!pg_class_ownercheck(relid, GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS,
stmt->sequence->relname);
/* do the work */
AlterSequenceInternal(relid, stmt->options);
}
/*
* AlterSequenceInternal
*
* Same as AlterSequence except that the sequence is specified by OID
* and we assume the caller already checked permissions.
*/
void
AlterSequenceInternal(Oid relid, List *options)
{
SeqTable elm;
Relation seqrel;
Buffer buf;
@@ -323,23 +351,14 @@ AlterSequence(AlterSeqStmt *stmt)
List *owned_by;
/* open and AccessShareLock sequence */
relid = RangeVarGetRelid(stmt->sequence, false);
init_sequence(relid, &elm, &seqrel);
/* allow ALTER to sequence owner only */
if (!pg_class_ownercheck(elm->relid, GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS,
stmt->sequence->relname);
/* lock page' buffer and read tuple into new sequence structure */
seq = read_info(elm, seqrel, &buf);
page = BufferGetPage(buf);
/* Copy old values of options into workspace */
memcpy(&new, seq, sizeof(FormData_pg_sequence));
/* Check and set new values */
init_params(stmt->options, false, &new, &owned_by);
/* Fill workspace with appropriate new info */
init_params(options, false, &new, seq, &owned_by);
/* Clear local cache so that we don't think we have cached numbers */
/* Note that we do not change the currval() state */
@@ -970,7 +989,7 @@ read_info(SeqTable elm, Relation rel, Buffer *buf)
*/
static void
init_params(List *options, bool isInit,
Form_pg_sequence new, List **owned_by)
Form_pg_sequence new, Form_pg_sequence old, List **owned_by)
{
DefElem *last_value = NULL;
DefElem *increment_by = NULL;
@@ -982,6 +1001,12 @@ init_params(List *options, bool isInit,
*owned_by = NIL;
/* Copy old values of options into workspace */
if (old != NULL)
memcpy(new, old, sizeof(FormData_pg_sequence));
else
memset(new, 0, sizeof(FormData_pg_sequence));
foreach(option, options)
{
DefElem *defel = (DefElem *) lfirst(option);
@@ -994,13 +1019,24 @@ init_params(List *options, bool isInit,
errmsg("conflicting or redundant options")));
increment_by = defel;
}
/*
* start is for a new sequence restart is for alter
*/
else if (strcmp(defel->defname, "start") == 0 ||
strcmp(defel->defname, "restart") == 0)
else if (strcmp(defel->defname, "start") == 0)
{
if (!isInit)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("use RESTART not START in ALTER SEQUENCE")));
if (last_value)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("conflicting or redundant options")));
last_value = defel;
}
else if (strcmp(defel->defname, "restart") == 0)
{
if (isInit)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("use START not RESTART in CREATE SEQUENCE")));
if (last_value)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
@@ -1109,24 +1145,59 @@ init_params(List *options, bool isInit,
bufm, bufx)));
}
/* START WITH */
/* START/RESTART [WITH] */
if (last_value != NULL)
{
new->last_value = defGetInt64(last_value);
if (last_value->arg != NULL)
new->last_value = defGetInt64(last_value);
else
{
Assert(old != NULL);
new->last_value = old->start_value;
}
if (isInit)
new->start_value = new->last_value;
new->is_called = false;
new->log_cnt = 1;
}
else if (isInit)
{
if (new->increment_by > 0)
new->last_value = new->min_value; /* ascending seq */
new->start_value = new->min_value; /* ascending seq */
else
new->last_value = new->max_value; /* descending seq */
new->start_value = new->max_value; /* descending seq */
new->last_value = new->start_value;
new->is_called = false;
new->log_cnt = 1;
}
/* crosscheck */
/* crosscheck START */
if (new->start_value < new->min_value)
{
char bufs[100],
bufm[100];
snprintf(bufs, sizeof(bufs), INT64_FORMAT, new->start_value);
snprintf(bufm, sizeof(bufm), INT64_FORMAT, new->min_value);
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("START value (%s) cannot be less than MINVALUE (%s)",
bufs, bufm)));
}
if (new->start_value > new->max_value)
{
char bufs[100],
bufm[100];
snprintf(bufs, sizeof(bufs), INT64_FORMAT, new->start_value);
snprintf(bufm, sizeof(bufm), INT64_FORMAT, new->max_value);
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("START value (%s) cannot be greater than MAXVALUE (%s)",
bufs, bufm)));
}
/* must crosscheck RESTART separately */
if (new->last_value < new->min_value)
{
char bufs[100],
@@ -1136,7 +1207,7 @@ init_params(List *options, bool isInit,
snprintf(bufm, sizeof(bufm), INT64_FORMAT, new->min_value);
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("START value (%s) cannot be less than MINVALUE (%s)",
errmsg("RESTART value (%s) cannot be less than MINVALUE (%s)",
bufs, bufm)));
}
if (new->last_value > new->max_value)
@@ -1148,7 +1219,7 @@ init_params(List *options, bool isInit,
snprintf(bufm, sizeof(bufm), INT64_FORMAT, new->max_value);
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("START value (%s) cannot be greater than MAXVALUE (%s)",
errmsg("RESTART value (%s) cannot be greater than MAXVALUE (%s)",
bufs, bufm)));
}

57
src/backend/commands/tablecmds.c
View File

@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.253 2008/05/12 00:00:48 alvherre Exp $
* $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.254 2008/05/16 23:36:04 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -37,6 +37,7 @@
#include "catalog/toasting.h"
#include "commands/cluster.h"
#include "commands/defrem.h"
#include "commands/sequence.h"
#include "commands/tablecmds.h"
#include "commands/tablespace.h"
#include "commands/trigger.h"
@@ -531,6 +532,7 @@ ExecuteTruncate(TruncateStmt *stmt)
{
List *rels = NIL;
List *relids = NIL;
List *seq_relids = NIL;
EState *estate;
ResultRelInfo *resultRelInfos;
ResultRelInfo *resultRelInfo;
@@ -596,6 +598,40 @@ ExecuteTruncate(TruncateStmt *stmt)
heap_truncate_check_FKs(rels, false);
#endif
/*
* If we are asked to restart sequences, find all the sequences,
* lock them (we only need AccessShareLock because that's all that
* ALTER SEQUENCE takes), and check permissions. We want to do this
* early since it's pointless to do all the truncation work only to fail
* on sequence permissions.
*/
if (stmt->restart_seqs)
{
foreach(cell, rels)
{
Relation rel = (Relation) lfirst(cell);
List *seqlist = getOwnedSequences(RelationGetRelid(rel));
ListCell *seqcell;
foreach(seqcell, seqlist)
{
Oid seq_relid = lfirst_oid(seqcell);
Relation seq_rel;
seq_rel = relation_open(seq_relid, AccessShareLock);
/* This check must match AlterSequence! */
if (!pg_class_ownercheck(seq_relid, GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS,
RelationGetRelationName(seq_rel));
seq_relids = lappend_oid(seq_relids, seq_relid);
relation_close(seq_rel, NoLock);
}
}
}
/* Prepare to catch AFTER triggers. */
AfterTriggerBeginQuery();
@@ -694,6 +730,25 @@ ExecuteTruncate(TruncateStmt *stmt)
heap_close(rel, NoLock);
}
/*
* Lastly, restart any owned sequences if we were asked to. This is done
* last because it's nontransactional: restarts will not roll back if
* we abort later. Hence it's important to postpone them as long as
* possible. (This is also a big reason why we locked and
* permission-checked the sequences beforehand.)
*/
if (stmt->restart_seqs)
{
List *options = list_make1(makeDefElem("restart", NULL));
foreach(cell, seq_relids)
{
Oid seq_relid = lfirst_oid(cell);
AlterSequenceInternal(seq_relid, options);
}
}
}
/*