On Tue, Oct 17, 2017 at 2:29 AM, Thomas Munro <thomas.mu...@enterprisedb.com> wrote: > Vik Fearing asked off-list why hash joins appear to read slightly more > temporary data than they write. The reason is that we notch up a > phantom block read when we hit the end of each file. Harmless but it > looks a bit weird and it's easily fixed. > > Unpatched, a 16 batch hash join reports that we read 30 more blocks > than we wrote (2 per batch after the first, as expected): > > Buffers: shared hit=434 read=16234, temp read=5532 written=5502 > > With the attached patch: > > Buffers: shared hit=547 read=16121, temp read=5502 written=5502
Committed. Arguably we ought to back-patch this, but it's minor so I didn't. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
