Re: [HACKERS] GSoC 2017 : Patch for predicate locking in Gist index - Mailing list pgsql-hackers

On 06/16/2017 01:24 PM, Shubham Barai wrote:

@@ -497,6 +499,13 @@ gistplacetopage(Relation rel, Size freespace, GISTSTATE *giststate,
                        for (ptr = dist->next; ptr; ptr = ptr->next)
                                UnlockReleaseBuffer(ptr->buffer);
                }
+
+               for (ptr = dist; ptr; ptr = ptr->next)
+                       PredicateLockPageSplit(rel,
+                                               BufferGetBlockNumber(buffer),
+                                               BufferGetBlockNumber(ptr->buffer));
+
+

I think this new code needs to go before the UnlockReleaseBuffer() calls above. Calling BufferGetBlockNumber() on an already-released buffer is not cool.

- Heikki