Hi,
As specified in $subject, if the bitmap constructed by bitmap index
scan is non-lossy i.e. row-level bitmap, then showing "Recheck Cond"
in EXPLAIN ANALYZE output is pointless. However in EXPLAIN without
ANALYZE we can't say the bitmap is actually a non-lossy one, as we
don't actually construct the "original" bitmap, so showing "Recheck
Cond" in this case makes sense.
Attaching a small patch that corrects EXPLAIN ANALYZE output for bitmap scans.
Note: $subject is identified in [1].
Thoughts?
[1] - https://www.youtube.com/watch?v=UXKYAZOWDgk ---> at 13:50 (mm:ss)
With Regards,
Bharath Rupireddy.
EnterpriseDB: http://www.enterprisedb.com