On 16/01/15 16:06, Mark Kirkwood wrote:
A bit more poking about shows that the major factor (which this fake dataset anyway) is the default for effective_cache_size (changes from 128MB to 4GB in 9.4). Increasing this makes 9.2 start using the files_in_flight index in a plain index scan too.
Arrg - misread the planner output....in 9.2 what changes is a plan that uses an index scan on the *file_state* index (not files_in_flight)...which appears much faster than the bitmap scan on file_state. Apologies for the confusion.
I'm thinking that I'm seeing the effect Tom has just mentioned. regards Mark -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
