Horton

Add comments on avoid reuse of parse-time snapshot

Alvaro Herrera <alvherre@alvh.no-ip.org>

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Commit: db989184cda7f4aa1ff764cca96142029e7e093b
Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
Date: 2020-02-28T16:25:26Z
Releases: 13.0 
Add comments on avoid reuse of parse-time snapshot

Apparently, reusing the parse-time query snapshot for later steps
(execution) is a frequently considered optimization ... but it doesn't
work, for reasons discovered in thread [1].  Adding some comments about
why it doesn't really work can relieve some future hackers from wasting
time reimplementing it again.

[1] https://postgr.es/m/flat/5075D8DF.6050500@fuzzy.cz

Author: Michail Nikolaev
Discussion: https://postgr.es/m/CANtu0ogp6cTvMJObXP8n=k+JtqxY1iT9UV5MbGCpjjPa5crCiw@mail.gmail.com

Files

PathChange+/−
src/backend/tcop/postgres.c modified +10 −1

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