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Make DDL operations play nicely with Serializable Snapshot Isolation.

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Truncating or dropping a table is treated like deletion of all tuples, and
check for conflicts accordingly. If a table is clustered or rewritten by
ALTER TABLE, all predicate locks on the heap are promoted to relation-level
locks, because the tuple or page ids of any existing tuples will change and
won't be valid after rewriting the table. Arguably ALTER TABLE should be
treated like a mass-UPDATE of every row, but if you e.g change the datatype
of a column, you could also argue that it's just a change to the physical
layout, not a logical change. Reindexing promotes all locks on the index to
relation-level lock on the heap.

Kevin Grittner, with a lot of cosmetic changes by me.
This commit is contained in:
Heikki Linnakangas
2011-06-08 13:47:21 +03:00
parent 16925c1e1f
commit 8f9622bbb3
7 changed files with 499 additions and 80 deletions
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src/include/storage/predicate.h
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@@ -49,11 +49,13 @@ extern void PredicateLockPage(const Relation relation, const BlockNumber blkno);
extern void PredicateLockTuple(const Relation relation, const HeapTuple tuple);
extern void PredicateLockPageSplit(const Relation relation, const BlockNumber oldblkno, const BlockNumber newblkno);
extern void PredicateLockPageCombine(const Relation relation, const BlockNumber oldblkno, const BlockNumber newblkno);
extern void TransferPredicateLocksToHeapRelation(const Relation relation);
extern void ReleasePredicateLocks(const bool isCommit);
/* conflict detection (may also trigger rollback) */
extern void CheckForSerializableConflictOut(const bool valid, const Relation relation, const HeapTuple tuple, const Buffer buffer);
extern void CheckForSerializableConflictIn(const Relation relation, const HeapTuple tuple, const Buffer buffer);
extern void CheckTableForSerializableConflictIn(const Relation relation);
/* final rollback checking */
extern void PreCommit_CheckForSerializationFailure(void);