| From: | Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org> |
|---|---|
| To: | pgsql-committers(at)lists(dot)postgresql(dot)org |
| Subject: | pgsql: Add comments on avoid reuse of parse-time snapshot |
| Date: | 2020-02-28 16:27:07 |
| Message-ID: | E1j7iTj-0001mr-0o@gemulon.postgresql.org |
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| Lists: | pgsql-committers |
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(dot)6050500(at)fuzzy(dot)cz
Author: Michail Nikolaev
Discussion: https://postgr.es/m/CANtu0ogp6cTvMJObXP8n=k+JtqxY1iT9UV5MbGCpjjPa5crCiw@mail.gmail.com
Branch
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master
Details
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https://git.postgresql.org/pg/commitdiff/db989184cda7f4aa1ff764cca96142029e7e093b
Modified Files
--------------
src/backend/tcop/postgres.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
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