Amit Langote wrote: > On 9/4/2015 9:22 AM, Tatsuo Ishii wrote: > >> > >> In this case, scan->rs_startblock is 384 set by IndexBuildHeapRangeScan() > >> using heap_setscanlimits(). One can imagine how the above heap finish > >> criteria might not work as expected. > > > > What scares me is: > > > > 1) the bug will not be found unless someone inspects the internal data > > of BRIN. Regression test is useless here. > > > > 2) the bug effectively causes vacuum scans the heap *twice*, which > > will produce lots of I/O if the heap is not small. > > > > 3) I wonder if other index type is suffered by this type of bug. > > > > About 3, it seems unlikely. Both the IndexBuildHeapRangeScan() and > heap_setscanlimits() were introduced by the BRIN patch and I didn't find > anything else using it, yet.
As I recall, there's some patch that Robert Haas or Amit Kapila that wants to use that function. Maybe something in the parallel seqscan patch series? -- Álvaro Herrera http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
