Re: Question about shared_buffer cache behavior

On Friday, March 18, 2016 4:54 PM, Andreas Kretschmer <andreas@a-kretschmer.de>
wrote:
 >
 >
 >> Paul Jones <pbj@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