[PATCH] Add extra statistics to explain for Nested Loop

From: e(dot)sokolova(at)postgrespro(dot)ru
To: pgsql-hackers(at)postgresql(dot)org
Subject: [PATCH] Add extra statistics to explain for Nested Loop
Date: 2020-10-16 07:42:43
Message-ID: f6490a9dec1b97118ac5a8509f095877@postgrespro.ru
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Hi, hackers.
For some distributions of data in tables, different loops in nested loop
joins can take different time and process different amounts of entries.
It makes average statistics returned by explain analyze not very useful
for DBA.
To fix it, here is the patch that add printing of min and max statistics
for time and rows across all loops in Nested Loop to EXPLAIN ANALYSE.
Please don't hesitate to share any thoughts on this topic!
Ekaterina Sokolova
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company

Attachment Content-Type Size
extra_statistics_v0.patch text/x-diff 32.6 KB
example_v0.sql text/plain 402.7 KB


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