Improve vacuum code to track minimum Xids per table instead of per database.

[postgresql] / src / backend / commands / dbcommands.c

diff --git a/src/backend/commands/dbcommands.c b/src/backend/commands/dbcommands.c
index 518fed819689db16c85d43b9f178dee35a11afba..6d744a5bad32f524d19219e83bde704af5b32079 100644 (file)
--- a/src/backend/commands/dbcommands.c
+++ b/src/backend/commands/dbcommands.c
@@ -13,7 +13,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/commands/dbcommands.c,v 1.181 2006/05/04 16:07:29 tgl Exp $
+ *       $PostgreSQL: pgsql/src/backend/commands/dbcommands.c,v 1.182 2006/07/10 16:20:50 alvherre Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -55,7 +55,7 @@ static bool get_db_info(const char *name, LOCKMODE lockmode,
                        Oid *dbIdP, Oid *ownerIdP,
                        int *encodingP, bool *dbIsTemplateP, bool *dbAllowConnP,
                        Oid *dbLastSysOidP,
-                       TransactionId *dbVacuumXidP, TransactionId *dbFrozenXidP,
+                       TransactionId *dbVacuumXidP, TransactionId *dbMinXidP,
                        Oid *dbTablespace);
 static bool have_createdb_privilege(void);
 static void remove_dbtablespaces(Oid db_id);
@@ -76,7 +76,7 @@ createdb(const CreatedbStmt *stmt)
        bool            src_allowconn;
        Oid                     src_lastsysoid;
        TransactionId src_vacuumxid;
-       TransactionId src_frozenxid;
+       TransactionId src_minxid;
        Oid                     src_deftablespace;
        volatile Oid dst_deftablespace;
        Relation        pg_database_rel;
@@ -228,7 +228,7 @@ createdb(const CreatedbStmt *stmt)
        if (!get_db_info(dbtemplate, ShareLock,
                                         &src_dboid, &src_owner, &src_encoding,
                                         &src_istemplate, &src_allowconn, &src_lastsysoid,
-                                        &src_vacuumxid, &src_frozenxid, &src_deftablespace))
+                                        &src_vacuumxid, &src_minxid, &src_deftablespace))
                ereport(ERROR,
                                (errcode(ERRCODE_UNDEFINED_DATABASE),
                                 errmsg("template database \"%s\" does not exist",
@@ -326,16 +326,6 @@ createdb(const CreatedbStmt *stmt)
                /* Note there is no additional permission check in this path */
        }
 
-       /*
-        * Normally we mark the new database with the same datvacuumxid and
-        * datfrozenxid as the source.  However, if the source is not allowing
-        * connections then we assume it is fully frozen, and we can set the
-        * current transaction ID as the xid limits.  This avoids immediately
-        * starting to generate warnings after cloning template0.
-        */
-       if (!src_allowconn)
-               src_vacuumxid = src_frozenxid = GetCurrentTransactionId();
-
        /*
         * Check for db name conflict.  This is just to give a more friendly
         * error message than "unique index violation".  There's a race condition
@@ -367,7 +357,7 @@ createdb(const CreatedbStmt *stmt)
        new_record[Anum_pg_database_datconnlimit - 1] = Int32GetDatum(dbconnlimit);
        new_record[Anum_pg_database_datlastsysoid - 1] = ObjectIdGetDatum(src_lastsysoid);
        new_record[Anum_pg_database_datvacuumxid - 1] = TransactionIdGetDatum(src_vacuumxid);
-       new_record[Anum_pg_database_datfrozenxid - 1] = TransactionIdGetDatum(src_frozenxid);
+       new_record[Anum_pg_database_datminxid - 1] = TransactionIdGetDatum(src_minxid);
        new_record[Anum_pg_database_dattablespace - 1] = ObjectIdGetDatum(dst_deftablespace);
 
        /*
@@ -1066,7 +1056,7 @@ get_db_info(const char *name, LOCKMODE lockmode,
                        Oid *dbIdP, Oid *ownerIdP,
                        int *encodingP, bool *dbIsTemplateP, bool *dbAllowConnP,
                        Oid *dbLastSysOidP,
-                       TransactionId *dbVacuumXidP, TransactionId *dbFrozenXidP,
+                       TransactionId *dbVacuumXidP, TransactionId *dbMinXidP,
                        Oid *dbTablespace)
 {
        bool            result = false;
@@ -1155,9 +1145,9 @@ get_db_info(const char *name, LOCKMODE lockmode,
                                /* limit of vacuumed XIDs */
                                if (dbVacuumXidP)
                                        *dbVacuumXidP = dbform->datvacuumxid;
-                               /* limit of frozen XIDs */
-                               if (dbFrozenXidP)
-                                       *dbFrozenXidP = dbform->datfrozenxid;
+                               /* limit of min XIDs */
+                               if (dbMinXidP)
+                                       *dbMinXidP = dbform->datminxid;
                                /* default tablespace for this database */
                                if (dbTablespace)
                                        *dbTablespace = dbform->dattablespace;