On 26 June 2013 07:46, Atri Sharma <atri.j...@gmail.com> wrote:
> I have been researching bloom filters and discussed it on IRC with > RhodiumToad and David Fetter, and they pointed me to the various > places that could potentially have bloom filters, apart from the > places that already have them currently. > > I have been reading the current implementation of hash joins, and in > ExecScanHashBucket, which I understand is the actual lookup function, > we could potentially look at a bloom filter per bucket. Instead of > actually looking up each hash value for the outer relation, we could > just check the corresponding bloom filter for that bucket, and if we > get a positive, then lookup the actual values i.e. continue with our > current behaviour (since we could be looking at a false positive). > Exactly this was suggested by me on the NTUP_PER_BUCKET thread last week. Probably good idea to join in there also. -- Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services
