I have been using the pager to generate grids , using Postgresql, I noticed that it issues two queries per pager request :
1. SELECT COUNT(*) FROM ( SELECT * orders )_ADODB_ALIAS_
2. SELECT * orders
The issue is for long running queries the combination of the SELECT COUNT(*) plus the SELECT, causes slow rendering times.. I have tried turning off the record count feature in pager, but this yields multiple SELECT queries as pager tries to figure out what the paging list it is on...