On 10/29/23 11:45, pf@xxxxxxxxxxx wrote:
On Sun, 29 Oct 2023 16:16:05 +0100 Peter J. Holzer wrote:
On 2023-10-29 09:21:46 -0400, pf@xxxxxxxxxxx wrote:
These are all static tables. Does PG maintain a table row count so as to
avoid having to count each time?
No. To count the rows in a table, Postgres has to actually read the
whole table (or an index, if a suitable index (e.g. a primary key)
exists).
Am I correct to assume count(fieldname) would only load that column for
counting?
The OS reads (chunks of) blocks, not individual bytes, and Postgresql is
record oriented, not column-oriented.
In other words: we should be specific (avoid "*") in general?
No.
--
Born in Arizona, moved to Babylonia.
