From 23616b47d54d0a0d39a626485299403264f7d8e1 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Fri, 27 Sep 2002 20:57:08 +0000
Subject: [PATCH] ARGH!
Vacuum must not advance pg_database.datvacuumxid nor truncate CLOG
unless it's processed *all* tables in the database. Vacuums run by
unprivileged users don't count.
(Beats head against nearest convenient wall...)
---
src/backend/commands/vacuum.c | 56 ++++++++++++++++++++++++-----------
1 file changed, 38 insertions(+), 18 deletions(-)
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 04c13be4e07..ba2aae57668 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -13,7 +13,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.240 2002/09/23 20:43:41 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.241 2002/09/27 20:57:08 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -105,9 +105,6 @@ static int elevel = -1;
static TransactionId OldestXmin;
static TransactionId FreezeLimit;
-static TransactionId initialOldestXmin;
-static TransactionId initialFreezeLimit;
-
/* non-export function prototypes */
static List *getrels(const RangeVar *vacrel, const char *stmttype);
@@ -116,7 +113,7 @@ static void vac_update_dbstats(Oid dbid,
TransactionId frozenXID);
static void vac_truncate_clog(TransactionId vacuumXID,
TransactionId frozenXID);
-static void vacuum_rel(Oid relid, VacuumStmt *vacstmt, char expected_relkind);
+static bool vacuum_rel(Oid relid, VacuumStmt *vacstmt, char expected_relkind);
static void full_vacuum_rel(Relation onerel, VacuumStmt *vacstmt);
static void scan_heap(VRelStats *vacrelstats, Relation onerel,
VacPageList vacuum_pages, VacPageList fraged_pages);
@@ -160,6 +157,9 @@ vacuum(VacuumStmt *vacstmt)
{
const char *stmttype = vacstmt->vacuum ? "VACUUM" : "ANALYZE";
MemoryContext anl_context = NULL;
+ TransactionId initialOldestXmin = InvalidTransactionId;
+ TransactionId initialFreezeLimit = InvalidTransactionId;
+ bool all_rels;
List *vrl,
*cur;
@@ -215,6 +215,9 @@ vacuum(VacuumStmt *vacstmt)
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
+ /* Assume we are processing everything unless one table is mentioned */
+ all_rels = (vacstmt->relation == NULL);
+
/* Build list of relations to process (note this lives in vac_context) */
vrl = getrels(vacstmt->relation, stmttype);
@@ -248,7 +251,7 @@ vacuum(VacuumStmt *vacstmt)
*/
if (vacstmt->vacuum)
{
- if (vacstmt->relation == NULL)
+ if (all_rels)
{
/*
* It's a database-wide VACUUM.
@@ -271,7 +274,8 @@ vacuum(VacuumStmt *vacstmt)
* recorded in pg_database.
*/
vacuum_set_xid_limits(vacstmt, false,
- &initialOldestXmin, &initialFreezeLimit);
+ &initialOldestXmin,
+ &initialFreezeLimit);
}
/* matches the StartTransaction in PostgresMain() */
@@ -286,7 +290,10 @@ vacuum(VacuumStmt *vacstmt)
Oid relid = (Oid) lfirsti(cur);
if (vacstmt->vacuum)
- vacuum_rel(relid, vacstmt, RELKIND_RELATION);
+ {
+ if (! vacuum_rel(relid, vacstmt, RELKIND_RELATION))
+ all_rels = false; /* forget about updating dbstats */
+ }
if (vacstmt->analyze)
{
MemoryContext old_context = NULL;
@@ -331,11 +338,11 @@ vacuum(VacuumStmt *vacstmt)
StartTransactionCommand(true);
/*
- * If we did a database-wide VACUUM, update the database's
- * pg_database row with info about the transaction IDs used, and
- * try to truncate pg_clog.
+ * If we completed a database-wide VACUUM without skipping any
+ * relations, update the database's pg_database row with info
+ * about the transaction IDs used, and try to truncate pg_clog.
*/
- if (vacstmt->relation == NULL)
+ if (all_rels)
{
vac_update_dbstats(MyDatabaseId,
initialOldestXmin, initialFreezeLimit);
@@ -693,6 +700,11 @@ vac_truncate_clog(TransactionId vacuumXID, TransactionId frozenXID)
/*
* vacuum_rel() -- vacuum one heap relation
*
+ * Returns TRUE if we actually processed the relation (or can ignore it
+ * for some reason), FALSE if we failed to process it due to permissions
+ * or other reasons. (A FALSE result really means that some data
+ * may have been left unvacuumed, so we can't update XID stats.)
+ *
* Doing one heap at a time incurs extra overhead, since we need to
* check that the heap exists again just before we vacuum it. The
* reason that we do this is so that vacuuming can be spread across
@@ -701,13 +713,14 @@ vac_truncate_clog(TransactionId vacuumXID, TransactionId frozenXID)
*
* At entry and exit, we are not inside a transaction.
*/
-static void
+static bool
vacuum_rel(Oid relid, VacuumStmt *vacstmt, char expected_relkind)
{
LOCKMODE lmode;
Relation onerel;
LockRelId onerelid;
Oid toast_relid;
+ bool result;
/* Begin a transaction for vacuuming this relation */
StartTransactionCommand(true);
@@ -727,7 +740,7 @@ vacuum_rel(Oid relid, VacuumStmt *vacstmt, char expected_relkind)
0, 0, 0))
{
CommitTransactionCommand(true);
- return;
+ return true; /* okay 'cause no data there */
}
/*
@@ -759,7 +772,7 @@ vacuum_rel(Oid relid, VacuumStmt *vacstmt, char expected_relkind)
RelationGetRelationName(onerel));
relation_close(onerel, lmode);
CommitTransactionCommand(true);
- return;
+ return false;
}
/*
@@ -772,7 +785,7 @@ vacuum_rel(Oid relid, VacuumStmt *vacstmt, char expected_relkind)
RelationGetRelationName(onerel));
relation_close(onerel, lmode);
CommitTransactionCommand(true);
- return;
+ return false;
}
/*
@@ -786,7 +799,7 @@ vacuum_rel(Oid relid, VacuumStmt *vacstmt, char expected_relkind)
{
relation_close(onerel, lmode);
CommitTransactionCommand(true);
- return;
+ return true; /* assume no long-lived data in temp tables */
}
/*
@@ -815,6 +828,8 @@ vacuum_rel(Oid relid, VacuumStmt *vacstmt, char expected_relkind)
else
lazy_vacuum_rel(onerel, vacstmt);
+ result = true; /* did the vacuum */
+
/* all done with this class, but hold lock until commit */
relation_close(onerel, NoLock);
@@ -831,12 +846,17 @@ vacuum_rel(Oid relid, VacuumStmt *vacstmt, char expected_relkind)
* statistics are totally unimportant for toast relations.
*/
if (toast_relid != InvalidOid)
- vacuum_rel(toast_relid, vacstmt, RELKIND_TOASTVALUE);
+ {
+ if (! vacuum_rel(toast_relid, vacstmt, RELKIND_TOASTVALUE))
+ result = false; /* failed to vacuum the TOAST table? */
+ }
/*
* Now release the session-level lock on the master table.
*/
UnlockRelationForSession(&onerelid, lmode);
+
+ return result;
}
--
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