Re: [DOCS] [ADMIN] shared_buffers and shmmax
Bruce Momjian writes: > Tom Lane wrote: >> * If we do it like this then the left-hand column is really redundant, >> not to say wrong because the right-hand formulas depend on more than >> the single variable mentioned. How about something like >> >> Table 17-2 PostgreSQL shared memory usage >> >> Purpose Approximate number of bytes required >> (as of 8.3) >> >> Per-connection state (1800 + 270 * max_locks_per_transaction) * >> max_connections >> Autovacuum worker state (1800 + 270 * >> max_locks_per_transaction) * autovacuum_max_workers >> Prepared transaction state ... >> Shared disk buffers ... >> WAL buffers ... >> Fixed space requirements 770kB > OK, I updated it again: > http://momjian.us/tmp/pgsql/kernel-resources.html > I did change your left column wording because it could be interpreted as > something that changes during server execution, e.g. connections. [ shrug... ] I don't find what you did to be an improvement over what I suggested, but I don't have time to argue about it. regards, tom lane -- Sent via pgsql-docs mailing list ([email protected]) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-docs
Re: [DOCS] [ADMIN] shared_buffers and shmmax
Tom Lane wrote: > Bruce Momjian writes: > > Tom Lane wrote: > >> If you're going to give a formula, why not just give a formula, eg > > > You mean like this: > > http://momjian.us/tmp/pgsql/kernel-resources.html > > Yeah, more or less. A couple thoughts now that I see it worked out: > > * Combining the entries for max_connections and autovacuum_max_workers > is probably just making it look more complicated than it needs to. > How about two rows that just happen to have similar formulas, viz > > max_connections (1800 + 270 * max_locks_per_transaction) * > max_connections > autovacuum_max_workers(1800 + 270 * max_locks_per_transaction) * > autovacuum_max_workers > > * The right-hand column header should be something like "Approximate > shared memory bytes..." to avoid the impression that these formulas > are meant to be exact. > > * If we do it like this then the left-hand column is really redundant, > not to say wrong because the right-hand formulas depend on more than > the single variable mentioned. How about something like > > Table 17-2 PostgreSQL shared memory usage > > Purpose Approximate number of bytes required > (as of 8.3) > > Per-connection state (1800 + 270 * max_locks_per_transaction) * > max_connections > Autovacuum worker state (1800 + 270 * > max_locks_per_transaction) * autovacuum_max_workers > Prepared transaction state... > Shared disk buffers ... > WAL buffers ... > Fixed space requirements 770kB OK, I updated it again: http://momjian.us/tmp/pgsql/kernel-resources.html I did change your left column wording because it could be interpreted as something that changes during server execution, e.g. connections. -- Bruce Momjian http://momjian.us EnterpriseDB http://enterprisedb.com + If your life is a hard drive, Christ can be your backup. + -- Sent via pgsql-docs mailing list ([email protected]) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-docs
Re: [DOCS] [ADMIN] shared_buffers and shmmax
Tom Lane wrote: > Bruce Momjian writes: > > Tom Lane wrote: > >> * If we do it like this then the left-hand column is really redundant, > >> not to say wrong because the right-hand formulas depend on more than > >> the single variable mentioned. How about something like > >> > >> Table 17-2 PostgreSQL shared memory usage > >> > >> PurposeApproximate number of bytes required > >> (as of 8.3) > >> > >> Per-connection state (1800 + 270 * > >> max_locks_per_transaction) * max_connections > >> Autovacuum worker state(1800 + 270 * > >> max_locks_per_transaction) * autovacuum_max_workers > >> Prepared transaction state ... > >> Shared disk buffers... > >> WAL buffers... > >> Fixed space requirements 770kB > > > OK, I updated it again: > > > http://momjian.us/tmp/pgsql/kernel-resources.html > > > I did change your left column wording because it could be interpreted as > > something that changes during server execution, e.g. connections. > > [ shrug... ] I don't find what you did to be an improvement over what > I suggested, but I don't have time to argue about it. I decided I didn't like what I did either; updated version with new headings and shorter descriptions: http://momjian.us/tmp/pgsql/kernel-resources.html -- Bruce Momjian http://momjian.us EnterpriseDB http://enterprisedb.com + If your life is a hard drive, Christ can be your backup. + -- Sent via pgsql-docs mailing list ([email protected]) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-docs
Re: [DOCS] [ADMIN] shared_buffers and shmmax
Bruce Momjian wrote: > I decided I didn't like what I did either; updated version with new > headings and shorter descriptions: > > http://momjian.us/tmp/pgsql/kernel-resources.html This version seems good to me, except please put back the B to the end of "770 k". -- Alvaro Herrerahttp://www.CommandPrompt.com/ PostgreSQL Replication, Consulting, Custom Development, 24x7 support -- Sent via pgsql-docs mailing list ([email protected]) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-docs
