Documentation mistake?
The following documentation comment has been logged on the website:
Page: https://www.postgresql.org/docs/17/indexes-bitmap-scans.html
Description:
In page https://www.postgresql.org/docs/current/indexes-bitmap-scans.html
написано следующее:
"Another example is that if we have separate indexes on x and y, one
possible implementation of a query like WHERE x = 5 AND y = 6 is to use each
index with the appropriate query clause and then AND together the index
results to identify the result rows".
You mean "WHERE x = 5 OR y = 6"?
result from index scan by x + result from index scan by y
Thx.
On Thursday, October 24, 2024, PG Doc comments form <noreply@postgresql.org>
wrote:
The following documentation comment has been logged on the website:
Page: https://www.postgresql.org/docs/17/indexes-bitmap-scans.html
Description:In page https://www.postgresql.org/docs/current/indexes-bitmap-scans.html
написано следующее:
"Another example is that if we have separate indexes on x and y, one
possible implementation of a query like WHERE x = 5 AND y = 6 is to use
each
index with the appropriate query clause and then AND together the index
results to identify the result rows".
This is a correct and intended sentence. The paragraph for bitmap covers
both OR from the earlier example and AND from this example.
David J.
PG Doc comments form <noreply@postgresql.org> writes:
In page https://www.postgresql.org/docs/current/indexes-bitmap-scans.html
написано следующее:
"Another example is that if we have separate indexes on x and y, one
possible implementation of a query like WHERE x = 5 AND y = 6 is to use each
index with the appropriate query clause and then AND together the index
results to identify the result rows".
You mean "WHERE x = 5 OR y = 6"?
No; the query says AND. Unioning the index results would be
appropriate if it said OR, but that's a different topic.
regards, tom lane