On 28/09/2023 19:06, Heikki Linnakangas wrote:
On 22/01/2023 18:23, Justin Pryzby wrote:
pg_stat_progress_analyze was added in v13 (a166d408e).
For tables with inheritance children, do_analyze_rel() and
acquire_sample_rows() are called twice. The first time through,
pgstat_progress_start_command() has memset() the progress array to zero.
But the 2nd time, ANALYZE_BLOCKS_DONE is already set from the previous
call, and BLOCKS_TOTAL can be set to some lower value (and in any case a
value unrelated to the pre-existing value of BLOCKS_DONE). So the
progress report briefly shows a bogus combination of values and, with
these assertions, fails regression tests in master and v13, unless
BLOCKS_DONE is first zeroed.
Good catch!
I think the counts need do be reset even earlier, in
acquire_inherited_sample_rows(), at the same time that we update
PROGRESS_ANALYZE_CURRENT_CHILD_TABLE_RELID. See attached patch.
Otherwise, there's a brief moment where we have already updated the
child table ID, but the PROGRESS_ANALYZE_BLOCKS_TOTAL
PROGRESS_ANALYZE_BLOCKS_DONE still show the counts from the previous
child table. And if it's a foreign table, the FDW's sampling function
might not update the progress report at all, in which case the old
values will be displayed until the table is fully processed.
Committed and backported. Thank you!
--
Heikki Linnakangas
Neon (https://neon.tech)
