From a0e842d81b435681a46e6dd1e50f14f9967ced37 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Fri, 25 Jun 2004 17:20:29 +0000
Subject: [PATCH] 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
---
doc/src/sgml/func.sgml | 65 +++++++++++------
src/backend/utils/adt/ruleutils.c | 114 +++++++++++++++++++++++++++++-
src/bin/pg_dump/pg_dump.c | 22 +++++-
src/include/catalog/catversion.h | 4 +-
src/include/catalog/pg_proc.h | 4 +-
src/include/utils/builtins.h | 5 +-
6 files changed, 185 insertions(+), 29 deletions(-)
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 106c4cf775f..3c23f43a59f 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -1,5 +1,5 @@
<!--
-$PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.210 2004/06/24 19:57:14 tgl Exp $
+$PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.211 2004/06/25 17:20:21 tgl Exp $
PostgreSQL documentation
-->
@@ -7228,29 +7228,13 @@ SELECT pg_type_is_visible('myschema.widget'::regtype);
<primary>pg_get_userbyid</primary>
</indexterm>
+ <indexterm zone="functions-misc">
+ <primary>pg_get_serial_sequence</primary>
+ </indexterm>
+
<para>
<xref linkend="functions-misc-catalog-table"> lists functions that
extract information from the system catalogs.
- <function>pg_get_viewdef</function>,
- <function>pg_get_ruledef</function>,
- <function>pg_get_indexdef</function>,
- <function>pg_get_triggerdef</function>, and
- <function>pg_get_constraintdef</function> respectively
- reconstruct the creating command for a view, rule, index, trigger, or
- constraint. (Note that this is a decompiled reconstruction, not
- the original text of the command.) Most of these come in two
- variants, one of which can optionally <quote>pretty-print</> the result.
- The pretty-printed format is more readable, but the default format is more
- likely to be
- interpreted the same way by future versions of <productname>PostgreSQL</>;
- avoid using pretty-printed output for dump purposes.
- Passing <literal>false</> for the pretty-print parameter yields the
- same result as the variant that does not have the parameter at all.
- <function>pg_get_expr</function> decompiles the internal form of an
- individual expression, such as the default value for a column. It
- may be useful when examining the contents of system catalogs.
- <function>pg_get_userbyid</function>
- extracts a user's name given a user ID number.
</para>
<table id="functions-misc-catalog-table">
@@ -7335,10 +7319,49 @@ SELECT pg_type_is_visible('myschema.widget'::regtype);
<entry><type>name</type></entry>
<entry>get user name with given ID</entry>
</row>
+ <row>
+ <entry><literal><function>pg_get_serial_sequence</function>(<parameter>table_name</parameter>, <parameter>column_name</parameter>)</literal></entry>
+ <entry><type>text</type></entry>
+ <entry>get name of the sequence that a serial or bigserial column
+ uses</entry>
+ </row>
</tbody>
</tgroup>
</table>
+ <para>
+ <function>pg_get_viewdef</function>,
+ <function>pg_get_ruledef</function>,
+ <function>pg_get_indexdef</function>,
+ <function>pg_get_triggerdef</function>, and
+ <function>pg_get_constraintdef</function> respectively
+ reconstruct the creating command for a view, rule, index, trigger, or
+ constraint. (Note that this is a decompiled reconstruction, not
+ the original text of the command.)
+ <function>pg_get_expr</function> decompiles the internal form of an
+ individual expression, such as the default value for a column. It
+ may be useful when examining the contents of system catalogs.
+ Most of these functions come in two
+ variants, one of which can optionally <quote>pretty-print</> the result.
+ The pretty-printed format is more readable, but the default format is more
+ likely to be
+ interpreted the same way by future versions of <productname>PostgreSQL</>;
+ avoid using pretty-printed output for dump purposes.
+ Passing <literal>false</> for the pretty-print parameter yields the
+ same result as the variant that does not have the parameter at all.
+ </para>
+
+ <para>
+ <function>pg_get_userbyid</function>
+ extracts a user's name given a user ID number.
+ <function>pg_get_serial_sequence</function>
+ fetches the name of the sequence associated with a serial or
+ bigserial column. The name is suitably formatted
+ for passing to the sequence functions (see <xref
+ linkend="functions-sequence">).
+ NULL is returned if the column does not have a sequence attached.
+ </para>
+
<indexterm zone="functions-misc">
<primary>obj_description</primary>
</indexterm>
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 1a2fe54d7ac..208cbf5d31b 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -3,7 +3,7 @@
* back to source text
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/utils/adt/ruleutils.c,v 1.173 2004/06/18 06:13:49 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/adt/ruleutils.c,v 1.174 2004/06/25 17:20:24 tgl Exp $
*
* This software is copyrighted by Jan Wieck - Hamburg.
*
@@ -42,12 +42,14 @@
#include "access/genam.h"
#include "catalog/catname.h"
+#include "catalog/dependency.h"
#include "catalog/heap.h"
#include "catalog/index.h"
#include "catalog/indexing.h"
#include "catalog/namespace.h"
#include "catalog/pg_cast.h"
#include "catalog/pg_constraint.h"
+#include "catalog/pg_depend.h"
#include "catalog/pg_index.h"
#include "catalog/pg_opclass.h"
#include "catalog/pg_operator.h"
@@ -1232,6 +1234,116 @@ pg_get_userbyid(PG_FUNCTION_ARGS)
PG_RETURN_NAME(result);
}
+
+/*
+ * pg_get_serial_sequence
+ * Get the name of the sequence used by a serial column,
+ * formatted suitably for passing to setval, nextval or currval.
+ */
+Datum
+pg_get_serial_sequence(PG_FUNCTION_ARGS)
+{
+ text *tablename = PG_GETARG_TEXT_P(0);
+ text *columnname = PG_GETARG_TEXT_P(1);
+ RangeVar *tablerv;
+ Oid tableOid;
+ char *column;
+ AttrNumber attnum;
+ Oid sequenceId = InvalidOid;
+ Relation depRel;
+ ScanKeyData key[3];
+ SysScanDesc scan;
+ HeapTuple tup;
+
+ /* Get the OID of the table */
+ tablerv = makeRangeVarFromNameList(textToQualifiedNameList(tablename,
+ "pg_get_serial_sequence"));
+ tableOid = RangeVarGetRelid(tablerv, false);
+
+ /* Get the number of the column */
+ column = DatumGetCString(DirectFunctionCall1(textout,
+ PointerGetDatum(columnname)));
+
+ attnum = get_attnum(tableOid, column);
+ if (attnum == InvalidAttrNumber)
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_COLUMN),
+ errmsg("column \"%s\" of relation \"%s\" does not exist",
+ column, tablerv->relname)));
+
+ /* Search the dependency table for the dependent sequence */
+ depRel = heap_openr(DependRelationName, AccessShareLock);
+
+ ScanKeyInit(&key[0],
+ Anum_pg_depend_refclassid,
+ BTEqualStrategyNumber, F_OIDEQ,
+ ObjectIdGetDatum(RelOid_pg_class));
+ ScanKeyInit(&key[1],
+ Anum_pg_depend_refobjid,
+ BTEqualStrategyNumber, F_OIDEQ,
+ ObjectIdGetDatum(tableOid));
+ ScanKeyInit(&key[2],
+ Anum_pg_depend_refobjsubid,
+ BTEqualStrategyNumber, F_INT4EQ,
+ Int32GetDatum(attnum));
+
+ scan = systable_beginscan(depRel, DependReferenceIndex, true,
+ SnapshotNow, 3, key);
+
+ while (HeapTupleIsValid(tup = systable_getnext(scan)))
+ {
+ Form_pg_depend deprec = (Form_pg_depend) GETSTRUCT(tup);
+
+ /*
+ * We assume any internal dependency of a relation on a column
+ * must be what we are looking for.
+ */
+ if (deprec->classid == RelOid_pg_class &&
+ deprec->objsubid == 0 &&
+ deprec->deptype == DEPENDENCY_INTERNAL)
+ {
+ sequenceId = deprec->objid;
+ break;
+ }
+ }
+
+ systable_endscan(scan);
+ heap_close(depRel, AccessShareLock);
+
+ if (OidIsValid(sequenceId))
+ {
+ HeapTuple classtup;
+ Form_pg_class classtuple;
+ char *nspname;
+ char *result;
+
+ /* Get the sequence's pg_class entry */
+ classtup = SearchSysCache(RELOID,
+ ObjectIdGetDatum(sequenceId),
+ 0, 0, 0);
+ if (!HeapTupleIsValid(classtup))
+ elog(ERROR, "cache lookup failed for relation %u", sequenceId);
+ classtuple = (Form_pg_class) GETSTRUCT(classtup);
+
+ /* Get the namespace */
+ nspname = get_namespace_name(classtuple->relnamespace);
+ if (!nspname)
+ elog(ERROR, "cache lookup failed for namespace %u",
+ classtuple->relnamespace);
+
+ /* And construct the result string */
+ result = quote_qualified_identifier(nspname,
+ NameStr(classtuple->relname));
+
+ ReleaseSysCache(classtup);
+
+ PG_RETURN_TEXT_P(string_to_text(result));
+ }
+
+ PG_RETURN_NULL();
+}
+
+
/* ----------
* deparse_expression - General utility for deparsing expressions
*
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 694a42e3b4a..00793ebbced 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -12,7 +12,7 @@
* by PostgreSQL
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/bin/pg_dump/pg_dump.c,v 1.376 2004/06/21 13:36:41 tgl Exp $
+ * $PostgreSQL: pgsql/src/bin/pg_dump/pg_dump.c,v 1.377 2004/06/25 17:20:26 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -7319,9 +7319,27 @@ dumpSequence(Archive *fout, TableInfo *tbinfo)
if (!schemaOnly)
{
+ TableInfo *owning_tab;
+
resetPQExpBuffer(query);
appendPQExpBuffer(query, "SELECT pg_catalog.setval(");
- appendStringLiteral(query, fmtId(tbinfo->dobj.name), true);
+ /*
+ * If this is a SERIAL sequence, then use the pg_get_serial_sequence
+ * function to avoid hard-coding the sequence name. Note that this
+ * implicitly assumes that the sequence and its owning table are in
+ * the same schema, because we don't schema-qualify the reference.
+ */
+ if (OidIsValid(tbinfo->owning_tab) &&
+ (owning_tab = findTableByOid(tbinfo->owning_tab)) != NULL)
+ {
+ appendPQExpBuffer(query, "pg_catalog.pg_get_serial_sequence(");
+ appendStringLiteral(query, fmtId(owning_tab->dobj.name), true);
+ appendPQExpBuffer(query, ", ");
+ appendStringLiteral(query, owning_tab->attnames[tbinfo->owning_col-1], true);
+ appendPQExpBuffer(query, ")");
+ }
+ else
+ appendStringLiteral(query, fmtId(tbinfo->dobj.name), true);
appendPQExpBuffer(query, ", %s, %s);\n",
last, (called ? "true" : "false"));
diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index 8bb47ad78c7..ac6f8a1fa0c 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -37,7 +37,7 @@
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.239 2004/06/21 04:06:07 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.240 2004/06/25 17:20:28 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -53,6 +53,6 @@
*/
/* yyyymmddN */
-#define CATALOG_VERSION_NO 200406202
+#define CATALOG_VERSION_NO 200406251
#endif
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index ecaf82efab1..489fa9ca9ba 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.338 2004/06/16 01:26:49 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.339 2004/06/25 17:20:28 tgl Exp $
*
* NOTES
* 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
DESCR("constraint description");
DATA(insert OID = 1716 ( pg_get_expr PGNSP PGUID 12 f f t f s 2 25 "25 26" _null_ pg_get_expr - _null_ ));
DESCR("deparse an encoded expression");
+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_ ));
+DESCR("name of sequence for a serial column");
/* Generic referential integrity constraint triggers */
diff --git a/src/include/utils/builtins.h b/src/include/utils/builtins.h
index 281f3067fa4..99974cdec12 100644
--- a/src/include/utils/builtins.h
+++ b/src/include/utils/builtins.h
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.243 2004/06/13 21:57:26 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.244 2004/06/25 17:20:29 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -472,9 +472,10 @@ extern Datum pg_get_triggerdef(PG_FUNCTION_ARGS);
extern Datum pg_get_constraintdef(PG_FUNCTION_ARGS);
extern Datum pg_get_constraintdef_ext(PG_FUNCTION_ARGS);
extern char *pg_get_constraintdef_string(Oid constraintId);
-extern Datum pg_get_userbyid(PG_FUNCTION_ARGS);
extern Datum pg_get_expr(PG_FUNCTION_ARGS);
extern Datum pg_get_expr_ext(PG_FUNCTION_ARGS);
+extern Datum pg_get_userbyid(PG_FUNCTION_ARGS);
+extern Datum pg_get_serial_sequence(PG_FUNCTION_ARGS);
extern char *deparse_expression(Node *expr, List *dpcontext,
bool forceprefix, bool showimplicit);
extern List *deparse_context_for(const char *aliasname, Oid relid);
--
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