Avoid displaying unnecessary "Recheck Cond" in EXPLAIN ANALYZE output if the bitmap is non-lossy - Mailing list pgsql-hackers

From Bharath Rupireddy
Subject Avoid displaying unnecessary "Recheck Cond" in EXPLAIN ANALYZE output if the bitmap is non-lossy
Date
Msg-id CALj2ACV36FXjVFWxKgxPr6ah1h0mdpcjz5G2DULONX0cGzXEDg@mail.gmail.com
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Responses Re: Avoid displaying unnecessary "Recheck Cond" in EXPLAIN ANALYZE output if the bitmap is non-lossy  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
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

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