Обсуждение: pgsql: Further adjustments to Hashagg EXPLAIN ANALYZE output

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pgsql: Further adjustments to Hashagg EXPLAIN ANALYZE output

От
David Rowley
Дата:
Further adjustments to Hashagg EXPLAIN ANALYZE output

The "Disk Usage" and "HashAgg Batches" properties in the EXPLAIN ANALYZE
output for HashAgg were previously only shown if the number of batches
was greater than 0.  Here we change this so that these properties are
always shown for EXPLAIN ANALYZE formats other than "text".  The idea here
is that since the HashAgg could have spilled to disk if there had been
more data or groups to aggregate, then it's relevant that we're clear in
the EXPLAIN ANALYZE output when no spilling occurred in this particular
execution of the given plan.

For the "text" EXPLAIN format, we still hide these properties when no
spilling occurs.  This EXPLAIN format is designed to be easy for humans
to read.  To maintain the readability we have a higher threshold for which
properties we display for this format.

Discussion: https://postgr.es/m/CAApHDvo_dmNozQQTmN-2jGp1vT%3Ddxx7Q0vd%2BMvD1cGpv2HU%3DSg%40mail.gmail.com
Backpatch-through: 13, where the hashagg spilling code was added.

Branch
------
REL_13_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/d73e9a57bf5bd977d9bf36bc07c77a1acf45e35b

Modified Files
--------------
src/backend/commands/explain.c | 21 +++++++--------------
1 file changed, 7 insertions(+), 14 deletions(-)