Indexes documentation bug

Started by Kouber Saparevabout 4 years ago3 messagesdocs
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#1Kouber Saparev
kouber@gmail.com

Hello,

I believe there is an error within this sentence in section
https://www.postgresql.org/docs/current/monitoring-stats.html#MONITORING-PG-STAT-USER-FUNCTIONS-VIEW

"Therefore, a bitmap scan increments the
pg_stat_all_indexes.idx_tup_read count(s)
for the index(es) it uses, and it increments the pg_stat_all_tables.
idx_tup_fetch count for the table, but it does not affect
pg_stat_all_indexes.idx_tup_fetch."

There is repeated mentioning of pg_stat_all_indexes.idx_tup_fetch while I
suppose one should read pg_stat_all_indexes.idx_scan instead the second
time. I.e. bitmap scans do not increment idx_scan.

Regards,
--
Kouber Saparev

#2Tom Lane
tgl@sss.pgh.pa.us
In reply to: Kouber Saparev (#1)
Re: Indexes documentation bug

Kouber Saparev <kouber@gmail.com> writes:

I believe there is an error within this sentence in section
https://www.postgresql.org/docs/current/monitoring-stats.html#MONITORING-PG-STAT-USER-FUNCTIONS-VIEW

"Therefore, a bitmap scan increments the
pg_stat_all_indexes.idx_tup_read count(s)
for the index(es) it uses, and it increments the pg_stat_all_tables.
idx_tup_fetch count for the table, but it does not affect
pg_stat_all_indexes.idx_tup_fetch."

There is repeated mentioning of pg_stat_all_indexes.idx_tup_fetch while I
suppose one should read pg_stat_all_indexes.idx_scan instead the second
time. I.e. bitmap scans do not increment idx_scan.

Um ... you did notice that the mentions of idx_tup_fetch apply to two
different views, pg_stat_all_tables vs pg_stat_all_indexes?

regards, tom lane

#3Kouber Saparev
kouber@gmail.com
In reply to: Tom Lane (#2)
Re: Indexes documentation bug

My bad, yes indeed, the view is different.

На пн, 4.04.2022 г. в 17:01 ч. Tom Lane <tgl@sss.pgh.pa.us> написа:

Show quoted text

Kouber Saparev <kouber@gmail.com> writes:

I believe there is an error within this sentence in section

https://www.postgresql.org/docs/current/monitoring-stats.html#MONITORING-PG-STAT-USER-FUNCTIONS-VIEW

"Therefore, a bitmap scan increments the
pg_stat_all_indexes.idx_tup_read count(s)
for the index(es) it uses, and it increments the pg_stat_all_tables.
idx_tup_fetch count for the table, but it does not affect
pg_stat_all_indexes.idx_tup_fetch."

There is repeated mentioning of pg_stat_all_indexes.idx_tup_fetch while I
suppose one should read pg_stat_all_indexes.idx_scan instead the second
time. I.e. bitmap scans do not increment idx_scan.

Um ... you did notice that the mentions of idx_tup_fetch apply to two
different views, pg_stat_all_tables vs pg_stat_all_indexes?

regards, tom lane