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Add pg_get_serial_sequence() function, and cause pg_dump to use it.
This eliminates the assumption that a serial column's sequence will have the same name on reload that it was given in the original database. Christopher Kings-Lynne
1 parent ef28802 commit a0e842d

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6 files changed

+185
-29
lines changed

6 files changed

+185
-29
lines changed

‎doc/src/sgml/func.sgml

Lines changed: 44 additions & 21 deletions
Original file line numberDiff line numberDiff line change
@@ -1,5 +1,5 @@
11
<!--
2-
$PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.210 2004/06/24 19:57:14 tgl Exp $
2+
$PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.211 2004/06/25 17:20:21 tgl Exp $
33
PostgreSQL documentation
44
-->
55

@@ -7228,29 +7228,13 @@ SELECT pg_type_is_visible('myschema.widget'::regtype);
72287228
<primary>pg_get_userbyid</primary>
72297229
</indexterm>
72307230

7231+
<indexterm zone="functions-misc">
7232+
<primary>pg_get_serial_sequence</primary>
7233+
</indexterm>
7234+
72317235
<para>
72327236
<xref linkend="functions-misc-catalog-table"> lists functions that
72337237
extract information from the system catalogs.
7234-
<function>pg_get_viewdef</function>,
7235-
<function>pg_get_ruledef</function>,
7236-
<function>pg_get_indexdef</function>,
7237-
<function>pg_get_triggerdef</function>, and
7238-
<function>pg_get_constraintdef</function> respectively
7239-
reconstruct the creating command for a view, rule, index, trigger, or
7240-
constraint. (Note that this is a decompiled reconstruction, not
7241-
the original text of the command.) Most of these come in two
7242-
variants, one of which can optionally <quote>pretty-print</> the result.
7243-
The pretty-printed format is more readable, but the default format is more
7244-
likely to be
7245-
interpreted the same way by future versions of <productname>PostgreSQL</>;
7246-
avoid using pretty-printed output for dump purposes.
7247-
Passing <literal>false</> for the pretty-print parameter yields the
7248-
same result as the variant that does not have the parameter at all.
7249-
<function>pg_get_expr</function> decompiles the internal form of an
7250-
individual expression, such as the default value for a column. It
7251-
may be useful when examining the contents of system catalogs.
7252-
<function>pg_get_userbyid</function>
7253-
extracts a user's name given a user ID number.
72547238
</para>
72557239

72567240
<table id="functions-misc-catalog-table">
@@ -7335,10 +7319,49 @@ SELECT pg_type_is_visible('myschema.widget'::regtype);
73357319
<entry><type>name</type></entry>
73367320
<entry>get user name with given ID</entry>
73377321
</row>
7322+
<row>
7323+
<entry><literal><function>pg_get_serial_sequence</function>(<parameter>table_name</parameter>, <parameter>column_name</parameter>)</literal></entry>
7324+
<entry><type>text</type></entry>
7325+
<entry>get name of the sequence that a serial or bigserial column
7326+
uses</entry>
7327+
</row>
73387328
</tbody>
73397329
</tgroup>
73407330
</table>
73417331

7332+
<para>
7333+
<function>pg_get_viewdef</function>,
7334+
<function>pg_get_ruledef</function>,
7335+
<function>pg_get_indexdef</function>,
7336+
<function>pg_get_triggerdef</function>, and
7337+
<function>pg_get_constraintdef</function> respectively
7338+
reconstruct the creating command for a view, rule, index, trigger, or
7339+
constraint. (Note that this is a decompiled reconstruction, not
7340+
the original text of the command.)
7341+
<function>pg_get_expr</function> decompiles the internal form of an
7342+
individual expression, such as the default value for a column. It
7343+
may be useful when examining the contents of system catalogs.
7344+
Most of these functions come in two
7345+
variants, one of which can optionally <quote>pretty-print</> the result.
7346+
The pretty-printed format is more readable, but the default format is more
7347+
likely to be
7348+
interpreted the same way by future versions of <productname>PostgreSQL</>;
7349+
avoid using pretty-printed output for dump purposes.
7350+
Passing <literal>false</> for the pretty-print parameter yields the
7351+
same result as the variant that does not have the parameter at all.
7352+
</para>
7353+
7354+
<para>
7355+
<function>pg_get_userbyid</function>
7356+
extracts a user's name given a user ID number.
7357+
<function>pg_get_serial_sequence</function>
7358+
fetches the name of the sequence associated with a serial or
7359+
bigserial column. The name is suitably formatted
7360+
for passing to the sequence functions (see <xref
7361+
linkend="functions-sequence">).
7362+
NULL is returned if the column does not have a sequence attached.
7363+
</para>
7364+
73427365
<indexterm zone="functions-misc">
73437366
<primary>obj_description</primary>
73447367
</indexterm>

‎src/backend/utils/adt/ruleutils.c

Lines changed: 113 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -3,7 +3,7 @@
33
* back to source text
44
*
55
* IDENTIFICATION
6-
* $PostgreSQL: pgsql/src/backend/utils/adt/ruleutils.c,v 1.173 2004/06/18 06:13:49 tgl Exp $
6+
* $PostgreSQL: pgsql/src/backend/utils/adt/ruleutils.c,v 1.174 2004/06/25 17:20:24 tgl Exp $
77
*
88
* This software is copyrighted by Jan Wieck - Hamburg.
99
*
@@ -42,12 +42,14 @@
4242

4343
#include "access/genam.h"
4444
#include "catalog/catname.h"
45+
#include "catalog/dependency.h"
4546
#include "catalog/heap.h"
4647
#include "catalog/index.h"
4748
#include "catalog/indexing.h"
4849
#include "catalog/namespace.h"
4950
#include "catalog/pg_cast.h"
5051
#include "catalog/pg_constraint.h"
52+
#include "catalog/pg_depend.h"
5153
#include "catalog/pg_index.h"
5254
#include "catalog/pg_opclass.h"
5355
#include "catalog/pg_operator.h"
@@ -1232,6 +1234,116 @@ pg_get_userbyid(PG_FUNCTION_ARGS)
12321234
PG_RETURN_NAME(result);
12331235
}
12341236

1237+
1238+
/*
1239+
* pg_get_serial_sequence
1240+
* Get the name of the sequence used by a serial column,
1241+
* formatted suitably for passing to setval, nextval or currval.
1242+
*/
1243+
Datum
1244+
pg_get_serial_sequence(PG_FUNCTION_ARGS)
1245+
{
1246+
text *tablename = PG_GETARG_TEXT_P(0);
1247+
text *columnname = PG_GETARG_TEXT_P(1);
1248+
RangeVar *tablerv;
1249+
Oid tableOid;
1250+
char *column;
1251+
AttrNumber attnum;
1252+
Oid sequenceId = InvalidOid;
1253+
Relation depRel;
1254+
ScanKeyData key[3];
1255+
SysScanDesc scan;
1256+
HeapTuple tup;
1257+
1258+
/* Get the OID of the table */
1259+
tablerv = makeRangeVarFromNameList(textToQualifiedNameList(tablename,
1260+
"pg_get_serial_sequence"));
1261+
tableOid = RangeVarGetRelid(tablerv, false);
1262+
1263+
/* Get the number of the column */
1264+
column = DatumGetCString(DirectFunctionCall1(textout,
1265+
PointerGetDatum(columnname)));
1266+
1267+
attnum = get_attnum(tableOid, column);
1268+
if (attnum == InvalidAttrNumber)
1269+
ereport(ERROR,
1270+
(errcode(ERRCODE_UNDEFINED_COLUMN),
1271+
errmsg("column \"%s\" of relation \"%s\" does not exist",
1272+
column, tablerv->relname)));
1273+
1274+
/* Search the dependency table for the dependent sequence */
1275+
depRel = heap_openr(DependRelationName, AccessShareLock);
1276+
1277+
ScanKeyInit(&key[0],
1278+
Anum_pg_depend_refclassid,
1279+
BTEqualStrategyNumber, F_OIDEQ,
1280+
ObjectIdGetDatum(RelOid_pg_class));
1281+
ScanKeyInit(&key[1],
1282+
Anum_pg_depend_refobjid,
1283+
BTEqualStrategyNumber, F_OIDEQ,
1284+
ObjectIdGetDatum(tableOid));
1285+
ScanKeyInit(&key[2],
1286+
Anum_pg_depend_refobjsubid,
1287+
BTEqualStrategyNumber, F_INT4EQ,
1288+
Int32GetDatum(attnum));
1289+
1290+
scan = systable_beginscan(depRel, DependReferenceIndex, true,
1291+
SnapshotNow, 3, key);
1292+
1293+
while (HeapTupleIsValid(tup = systable_getnext(scan)))
1294+
{
1295+
Form_pg_depend deprec = (Form_pg_depend) GETSTRUCT(tup);
1296+
1297+
/*
1298+
* We assume any internal dependency of a relation on a column
1299+
* must be what we are looking for.
1300+
*/
1301+
if (deprec->classid == RelOid_pg_class &&
1302+
deprec->objsubid == 0 &&
1303+
deprec->deptype == DEPENDENCY_INTERNAL)
1304+
{
1305+
sequenceId = deprec->objid;
1306+
break;
1307+
}
1308+
}
1309+
1310+
systable_endscan(scan);
1311+
heap_close(depRel, AccessShareLock);
1312+
1313+
if (OidIsValid(sequenceId))
1314+
{
1315+
HeapTuple classtup;
1316+
Form_pg_class classtuple;
1317+
char *nspname;
1318+
char *result;
1319+
1320+
/* Get the sequence's pg_class entry */
1321+
classtup = SearchSysCache(RELOID,
1322+
ObjectIdGetDatum(sequenceId),
1323+
0, 0, 0);
1324+
if (!HeapTupleIsValid(classtup))
1325+
elog(ERROR, "cache lookup failed for relation %u", sequenceId);
1326+
classtuple = (Form_pg_class) GETSTRUCT(classtup);
1327+
1328+
/* Get the namespace */
1329+
nspname = get_namespace_name(classtuple->relnamespace);
1330+
if (!nspname)
1331+
elog(ERROR, "cache lookup failed for namespace %u",
1332+
classtuple->relnamespace);
1333+
1334+
/* And construct the result string */
1335+
result = quote_qualified_identifier(nspname,
1336+
NameStr(classtuple->relname));
1337+
1338+
ReleaseSysCache(classtup);
1339+
1340+
PG_RETURN_TEXT_P(string_to_text(result));
1341+
}
1342+
1343+
PG_RETURN_NULL();
1344+
}
1345+
1346+
12351347
/* ----------
12361348
* deparse_expression - General utility for deparsing expressions
12371349
*

‎src/bin/pg_dump/pg_dump.c

Lines changed: 20 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -12,7 +12,7 @@
1212
* by PostgreSQL
1313
*
1414
* IDENTIFICATION
15-
* $PostgreSQL: pgsql/src/bin/pg_dump/pg_dump.c,v 1.376 2004/06/21 13:36:41 tgl Exp $
15+
* $PostgreSQL: pgsql/src/bin/pg_dump/pg_dump.c,v 1.377 2004/06/25 17:20:26 tgl Exp $
1616
*
1717
*-------------------------------------------------------------------------
1818
*/
@@ -7319,9 +7319,27 @@ dumpSequence(Archive *fout, TableInfo *tbinfo)
73197319

73207320
if (!schemaOnly)
73217321
{
7322+
TableInfo *owning_tab;
7323+
73227324
resetPQExpBuffer(query);
73237325
appendPQExpBuffer(query, "SELECT pg_catalog.setval(");
7324-
appendStringLiteral(query, fmtId(tbinfo->dobj.name), true);
7326+
/*
7327+
* If this is a SERIAL sequence, then use the pg_get_serial_sequence
7328+
* function to avoid hard-coding the sequence name. Note that this
7329+
* implicitly assumes that the sequence and its owning table are in
7330+
* the same schema, because we don't schema-qualify the reference.
7331+
*/
7332+
if (OidIsValid(tbinfo->owning_tab) &&
7333+
(owning_tab = findTableByOid(tbinfo->owning_tab)) != NULL)
7334+
{
7335+
appendPQExpBuffer(query, "pg_catalog.pg_get_serial_sequence(");
7336+
appendStringLiteral(query, fmtId(owning_tab->dobj.name), true);
7337+
appendPQExpBuffer(query, ", ");
7338+
appendStringLiteral(query, owning_tab->attnames[tbinfo->owning_col-1], true);
7339+
appendPQExpBuffer(query, ")");
7340+
}
7341+
else
7342+
appendStringLiteral(query, fmtId(tbinfo->dobj.name), true);
73257343
appendPQExpBuffer(query, ", %s, %s);\n",
73267344
last, (called ? "true" : "false"));
73277345

‎src/include/catalog/catversion.h

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -37,7 +37,7 @@
3737
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
3838
* Portions Copyright (c) 1994, Regents of the University of California
3939
*
40-
* $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.239 2004/06/21 04:06:07 tgl Exp $
40+
* $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.240 2004/06/25 17:20:28 tgl Exp $
4141
*
4242
*-------------------------------------------------------------------------
4343
*/
@@ -53,6 +53,6 @@
5353
*/
5454

5555
/* yyyymmddN */
56-
#define CATALOG_VERSION_NO 200406202
56+
#define CATALOG_VERSION_NO 200406251
5757

5858
#endif

‎src/include/catalog/pg_proc.h

Lines changed: 3 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -7,7 +7,7 @@
77
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
88
* Portions Copyright (c) 1994, Regents of the University of California
99
*
10-
* $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.338 2004/06/16 01:26:49 tgl Exp $
10+
* $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.339 2004/06/25 17:20:28 tgl Exp $
1111
*
1212
* NOTES
1313
* The script catalog/genbki.sh reads this file and generates .bki
@@ -2238,6 +2238,8 @@ DATA(insert OID = 1387 ( pg_get_constraintdef PGNSP PGUID 12 f f t f s 1 25 "26
22382238
DESCR("constraint description");
22392239
DATA(insert OID = 1716 ( pg_get_expr PGNSP PGUID 12 f f t f s 2 25 "25 26" _null_ pg_get_expr - _null_ ));
22402240
DESCR("deparse an encoded expression");
2241+
DATA(insert OID = 1665 ( pg_get_serial_sequence PGNSP PGUID 12 f f t f s 2 25 "25 25" _null_ pg_get_serial_sequence - _null_ ));
2242+
DESCR("name of sequence for a serial column");
22412243

22422244

22432245
/* Generic referential integrity constraint triggers */

‎src/include/utils/builtins.h

Lines changed: 3 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -7,7 +7,7 @@
77
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
88
* Portions Copyright (c) 1994, Regents of the University of California
99
*
10-
* $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.243 2004/06/13 21:57:26 tgl Exp $
10+
* $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.244 2004/06/25 17:20:29 tgl Exp $
1111
*
1212
*-------------------------------------------------------------------------
1313
*/
@@ -472,9 +472,10 @@ extern Datum pg_get_triggerdef(PG_FUNCTION_ARGS);
472472
extern Datum pg_get_constraintdef(PG_FUNCTION_ARGS);
473473
extern Datum pg_get_constraintdef_ext(PG_FUNCTION_ARGS);
474474
extern char *pg_get_constraintdef_string(Oid constraintId);
475-
extern Datum pg_get_userbyid(PG_FUNCTION_ARGS);
476475
extern Datum pg_get_expr(PG_FUNCTION_ARGS);
477476
extern Datum pg_get_expr_ext(PG_FUNCTION_ARGS);
477+
extern Datum pg_get_userbyid(PG_FUNCTION_ARGS);
478+
extern Datum pg_get_serial_sequence(PG_FUNCTION_ARGS);
478479
extern char *deparse_expression(Node *expr, List *dpcontext,
479480
bool forceprefix, bool showimplicit);
480481
extern List *deparse_context_for(const char *aliasname, Oid relid);

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