Bruce Momjian wrote:
> > This argument seems a tad peculiar, since the *entire* *point* of
> > pg_upgrade is to push physical files from one installation into another
> > even though compatibility isn't guaranteed. It is the program's duty to
> > understand enough to know whether it can transport the cluster's state
> > safely. Not to arbitrarily discard state because it might possibly not
> > be transportable.
>
> Well, pg_upgrade succeeds because it does as little as necessary to do
> the migration, relying on pg_dump to do much of the migration work at
> the catalog level. pg_upgrade tries to be involved as little as
> possible with the Postgres code so it doesn't have to be changed
> regularly between major versions.
>
> The prepared transaction case seems ugly enough that we don't want
> pg_upgrade to have to check every major release if anything changed
> about the data stored in prepared transactions. This is the same reason
> pg_upgrade doesn't transfer WAL files from the old cluster, just pg_clog
> files (which rarely changes its format).
I have applied the attached pg_upgrade patch to head and 9.1 to fail if
prepared transactions are in the old or new cluster.
--
Bruce Momjian <br...@momjian.us> http://momjian.us
EnterpriseDB http://enterprisedb.com
+ It's impossible for everything to be true. +
diff --git a/contrib/pg_upgrade/check.c b/contrib/pg_upgrade/check.c
new file mode 100644
index fdec6e3..376d25a
*** a/contrib/pg_upgrade/check.c
--- b/contrib/pg_upgrade/check.c
*************** static void check_old_cluster_has_new_cl
*** 16,21 ****
--- 16,22 ----
static void check_locale_and_encoding(ControlData *oldctrl,
ControlData *newctrl);
static void check_is_super_user(ClusterInfo *cluster);
+ static void check_for_prepared_transactions(ClusterInfo *cluster);
static void check_for_isn_and_int8_passing_mismatch(ClusterInfo *cluster);
static void check_for_reg_data_type_usage(ClusterInfo *cluster);
*************** check_old_cluster(bool live_check,
*** 65,70 ****
--- 66,72 ----
* Check for various failure cases
*/
check_is_super_user(&old_cluster);
+ check_for_prepared_transactions(&old_cluster);
check_for_reg_data_type_usage(&old_cluster);
check_for_isn_and_int8_passing_mismatch(&old_cluster);
*************** check_new_cluster(void)
*** 117,122 ****
--- 119,125 ----
get_db_and_rel_infos(&new_cluster);
check_new_cluster_is_empty();
+ check_for_prepared_transactions(&new_cluster);
check_old_cluster_has_new_cluster_dbs();
check_loadable_libraries();
*************** check_is_super_user(ClusterInfo *cluster
*** 507,512 ****
--- 510,545 ----
/*
+ * check_for_prepared_transactions()
+ *
+ * Make sure there are no prepared transactions because the storage format
+ * might have changed.
+ */
+ static void
+ check_for_prepared_transactions(ClusterInfo *cluster)
+ {
+ PGresult *res;
+ PGconn *conn = connectToServer(cluster, "template1");
+
+ prep_status("Checking for prepared transactions");
+
+ res = executeQueryOrDie(conn,
+ "SELECT * "
+ "FROM pg_catalog.pg_prepared_xact()");
+
+ if (PQntuples(res) != 0)
+ pg_log(PG_FATAL, "The %s cluster contains prepared transactions\n",
+ CLUSTER_NAME(cluster));
+
+ PQclear(res);
+
+ PQfinish(conn);
+
+ check_ok();
+ }
+
+
+ /*
* check_for_isn_and_int8_passing_mismatch()
*
* contrib/isn relies on data type int8, and in 8.4 int8 can now be passed
--
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