From 77489f4523c2258167ff1fdfce791972bb53bb91 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Mon, 4 Aug 2003 22:03:39 +0000
Subject: [PATCH] Update vacuumlo to be properly schema-aware. Improve
documentation.
---
contrib/vacuumlo/README.vacuumlo | 20 ++++++++++++++------
contrib/vacuumlo/vacuumlo.c | 31 +++++++++++++++++--------------
2 files changed, 31 insertions(+), 20 deletions(-)
diff --git a/contrib/vacuumlo/README.vacuumlo b/contrib/vacuumlo/README.vacuumlo
index 66a3323eb4f..77f9e281990 100644
--- a/contrib/vacuumlo/README.vacuumlo
+++ b/contrib/vacuumlo/README.vacuumlo
@@ -1,4 +1,4 @@
-$Header: /cvsroot/pgsql/contrib/vacuumlo/Attic/README.vacuumlo,v 1.2 2000/11/21 17:54:21 tgl Exp $
+$Header: /cvsroot/pgsql/contrib/vacuumlo/Attic/README.vacuumlo,v 1.3 2003/08/04 22:03:39 tgl Exp $
This is a simple utility that will remove any orphaned large objects out of a
PostgreSQL database. An orphaned LO is considered to be any LO whose OID
@@ -14,19 +14,27 @@ Simply run make. A single executable "vacuumlo" is created.
Usage
-----
-vacuumlo [-v] database [db2 ... dbn]
+vacuumlo [options] database [database2 ... databasen]
-The -v flag outputs some progress messages to stdout.
+All databases named on the command line are processed. Available options
+include:
+
+ -v Write a lot of progress messages
+ -n Don't remove large objects, just show what would be done
+ -U username Username to connect as
+ -W Prompt for password
+ -h hostname Database server host
+ -p port Database server port
Method
------
-First, it builds a temporary table which contains all of the oid's of the
+First, it builds a temporary table which contains all of the OIDs of the
large objects in that database.
-It then scans through all columns in the database that are of type 'oid',
-and removes any matching entries from the temporary table.
+It then scans through all columns in the database that are of type "oid"
+or "lo", and removes matching entries from the temporary table.
The remaining entries in the temp table identify orphaned LOs. These are
removed.
diff --git a/contrib/vacuumlo/vacuumlo.c b/contrib/vacuumlo/vacuumlo.c
index b827b2ef0f4..3db7cb9c713 100644
--- a/contrib/vacuumlo/vacuumlo.c
+++ b/contrib/vacuumlo/vacuumlo.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/contrib/vacuumlo/vacuumlo.c,v 1.21 2003/08/04 02:39:56 momjian Exp $
+ * $Header: /cvsroot/pgsql/contrib/vacuumlo/vacuumlo.c,v 1.22 2003/08/04 22:03:39 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -256,8 +256,9 @@ vacuumlo(char *database, struct _param * param)
/*
* Now find any candidate tables who have columns of type oid.
*
- * NOTE: the temp table formed above is ignored, because its real table
- * name will be pg_something. Also, pg_largeobject will be ignored.
+ * NOTE: we ignore system tables and temp tables by the expedient of
+ * rejecting tables in schemas named 'pg_*'. In particular, the temp
+ * table formed above is ignored, and pg_largeobject will be too.
* If either of these were scanned, obviously we'd end up with nothing
* to delete...
*
@@ -266,14 +267,14 @@ vacuumlo(char *database, struct _param * param)
*/
buf[0] = '\0';
strcat(buf, "SELECT c.relname, a.attname ");
- strcat(buf, "FROM pg_class c, pg_attribute a, pg_type t ");
+ strcat(buf, "FROM pg_class c, pg_attribute a, pg_namespace s, pg_type t ");
strcat(buf, "WHERE a.attnum > 0 ");
strcat(buf, " AND a.attrelid = c.oid ");
strcat(buf, " AND a.atttypid = t.oid ");
+ strcat(buf, " AND c.relnamespace = s.oid ");
strcat(buf, " AND t.typname in ('oid', 'lo') ");
strcat(buf, " AND c.relkind = 'r'");
- strcat(buf, " AND c.relname NOT LIKE 'pg_%'");
- strcat(buf, " AND c.relname != 'vacuum_l'");
+ strcat(buf, " AND s.nspname NOT LIKE 'pg\\\\_%'");
res = PQexec(conn, buf);
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
@@ -296,12 +297,14 @@ vacuumlo(char *database, struct _param * param)
fprintf(stdout, "Checking %s in %s\n", field, table);
/*
- * We use a DELETE with implicit join for efficiency. This is a
- * Postgres-ism and not portable to other DBMSs, but then this
- * whole program is a Postgres-ism.
+ * The "IN" construct used here was horribly inefficient before
+ * Postgres 7.4, but should be now competitive if not better than
+ * the bogus join we used before.
*/
- snprintf(buf, BUFSIZE, "DELETE FROM vacuum_l WHERE lo = \"%s\".\"%s\" ",
- table, field);
+ snprintf(buf, BUFSIZE,
+ "DELETE FROM vacuum_l "
+ "WHERE lo IN (SELECT \"%s\" FROM \"%s\")",
+ field, table);
res2 = PQexec(conn, buf);
if (PQresultStatus(res2) != PGRES_COMMAND_OK)
{
@@ -388,10 +391,10 @@ void
usage(void)
{
fprintf(stdout, "vacuumlo removes unreferenced large objects from databases\n\n");
- fprintf(stdout, "Usage:\n vacuumlo [options] dbname [dbnames...]\n\n");
+ fprintf(stdout, "Usage:\n vacuumlo [options] dbname [dbname ...]\n\n");
fprintf(stdout, "Options:\n");
- fprintf(stdout, " -v\t\tWrite a lot of output\n");
- fprintf(stdout, " -n\t\tDon't remove any large object, just show what would be done\n");
+ fprintf(stdout, " -v\t\tWrite a lot of progress messages\n");
+ fprintf(stdout, " -n\t\tDon't remove large objects, just show what would be done\n");
fprintf(stdout, " -U username\tUsername to connect as\n");
fprintf(stdout, " -W\t\tPrompt for password\n");
fprintf(stdout, " -h hostname\tDatabase server host\n");
--
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