Re: Planner performance extremely affected by an hanging transaction (20-30 times)? - Mailing list pgsql-performance

From Tom Lane
Subject Re: Planner performance extremely affected by an hanging transaction (20-30 times)?
Date
Msg-id 5815.1380018947@sss.pgh.pa.us
Whole thread Raw
In response to Re: Planner performance extremely affected by an hanging transaction (20-30 times)?  (Kevin Grittner <kgrittn@ymail.com>)
Responses Re: Planner performance extremely affected by an hanging transaction (20-30 times)?  (jesper@krogh.cc)
Re: Planner performance extremely affected by an hanging transaction (20-30 times)?  (Jeff Janes <jeff.janes@gmail.com>)
List pgsql-performance
Kevin Grittner <kgrittn@ymail.com> writes:
> Are we talking about the probe for the end (or beginning) of an
> index?  If so, should we even care about visibility of the row
> related to the most extreme index entry?  Should we even go to the
> heap during the plan phase?

Consider the case where some transaction inserted a wildly out-of-range
value, then rolled back.  If we don't check validity of the heap row,
we'd be using that silly endpoint value for planning purposes ---
indefinitely.  That's not an improvement over the situation that the
probe is meant to fix.

            regards, tom lane


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