On 13.06.2011 21:31, Tom Lane wrote:
So I finally started actually reading the SSI changes, and I am a tad
distressed by this:
diff --git a/src/include/access/twophase_rmgr.h
b/src/include/access/twophase_rmgr.h
index a541d0f..1c7d8bb 100644
--- a/src/include/access/twophase_rmgr.h
+++ b/src/include/access/twophase_rmgr.h
@@ -23,8 +23,9 @@ typedef uint8 TwoPhaseRmgrId;
*/
#define TWOPHASE_RM_END_ID 0
#define TWOPHASE_RM_LOCK_ID 1
-#define TWOPHASE_RM_PGSTAT_ID 2
-#define TWOPHASE_RM_MULTIXACT_ID 3
+#define TWOPHASE_RM_PREDICATELOCK_ID 2
+#define TWOPHASE_RM_PGSTAT_ID 3
+#define TWOPHASE_RM_MULTIXACT_ID 4
#define TWOPHASE_RM_MAX_ID TWOPHASE_RM_MULTIXACT_ID
extern const TwoPhaseCallback twophase_recover_callbacks[];
What was the rationale for changing the assignments of existing 2PC IDs?
As far as I can tell it was for purely cosmetic reasons, to have lock
and predicate lock lines together.
So far as I can tell, that breaks pg_upgrade (if there are any open
prepared transactions) for no redeeming social benefit.
Surely pg_upgrade can't work anyway if there's any open prepared
transactions in the database. We're not going to guarantee to keep all
the data structures we write in two-phase state files unchanged over
major releases. If pg_upgrade is not checking for prepared transcations
at the moment, such a check should probably should be added.
--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com
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