Thread

Re: Repeated PredicateLockRelation calls during seqscan

Kevin Grittner <kevin.grittner@wicourts.gov> — 2011-06-25T19:29:38Z

Heikki Linnakangas  wrote:
 
> BTW, isn't bitgetpage() in nodeBitmapHeapscan.c missing
> PredicateLockTuple() and CheckForSerializableConflictOut() calls in
> the codepath for a lossy bitmap? In the non-lossy case,
> heap_hot_search_buffer() takes care of it, but not in the lossy
> case.
 
I think the attached addresses that.
 
In looking this over I noticed something else that doesn't seem quite
right.  In heapam.c there are two places where the execution of
PredicateLockTuple() is conditioned not just on MVCC visibility, but
also on HeapKeyTest().  I think those calls should be moved to not be
conditioned on that.  Otherwise we have a predicate condition being
tested without "locking the gaps", don't we?
 
-Kevin