TFM says:
Sets the amount of memory the database server uses for shared memory
buffers. The default is typically 32 megabytes (32MB), but might be
less if your kernel settings will not support it (as determined during
initdb). This setting must be at least 128 kilobytes. (Non-default
values of BLCKSZ change the minimum.) However, settings significantly
higher than the minimum are usually needed for good performance.
Several tens of megabytes are recommended for production
installations.
So if the default is 32MB, and what I'm actually supposed to have is
"several tens of megabytes", isn't that pretty much the same thing? I
think this advice is badly outdated. s/tens/hundreds/ might be a good
idea at a minimum, but I'm thinking we might want to also mention the
one-quarter-of-system-memory heuristic.
...Robert