Thread: shared memory - progress

OK,
I can assign and manipulate shared memory in BSD/OS3.0 notes to follow.
Now the problem is that as I vary the number of shared buffers and amount of
shared memory I vary between two kinds of errors. If shared mem is too low
that generates an error - 'out of buffers', if too high, I get palloc
errors - memory exhausted.
So, now I need to lay my hands on a basic tutorial that describes in general
terms how BSD divides its total memory resource among shared/kernel etc. and
a second tutorial on how postgres uses different types of memory ie. why
does one query create a palloc error and another run out of shmem.
Thanks so much for hanging with me through this.
John

[Charset iso-8859-1 unsupported, filtering to ASCII...]
> OK,
> I can assign and manipulate shared memory in BSD/OS3.0 notes to follow.
> Now the problem is that as I vary the number of shared buffers and amount of
> shared memory I vary between two kinds of errors. If shared mem is too low
> that generates an error - 'out of buffers', if too high, I get palloc
> errors - memory exhausted.

Too low means you are asking for more shared memory than was configured
for your kernel.  palloc errors are because there is not enough memory
left for your query to complete.

Most palloc errors are caused by some user error, or too many OR's in a
query, which will be fixed in the next release.


--
  Bruce Momjian                        |  http://www.op.net/~candle
  maillist@candle.pha.pa.us            |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026