On Friday, March 18, 2016 4:54 PM, Andreas Kretschmer <andr...@a-kretschmer.de> wrote: > > >> Paul Jones <p...@cmicdo.com> hat am 18. Marz 2016 um 21:24 geschrieben: >> >> >> In Postgres 9.5.1 with a shared_buffer cache of 7Gb, a SELECT from
> > the first query reads only the tuple from heap that are matched the > where-condition. > The 2nd query with an other where-condition reads other rows than the first > query. > > Keep in mind: a index search reads the index and pulls the rows that matched the > condition from the heap, no more. Ok, thanks! I understand now! > > Regards > -- > Andreas Kretschmer > http://www.2ndQuadrant.com/ > PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
