Thread: Setting effective_cache_size in integer form with the 8kb block units
Sorry to be daft, but if I want 48GB for effective_cache size, should I put the integer value of 6291456 or 6000000?
Not quite sure how to spell out the 8kb units, decimal or binary...
Re: Setting effective_cache_size in integer form with the 8kb block units
From
"David G. Johnston"
Date:
On Wed, Jan 19, 2022 at 2:39 PM Wells Oliver <wells.oliver@gmail.com> wrote:
Sorry to be daft, but if I want 48GB for effective_cache size, should I put the integer value of 6291456 or 6000000?Not quite sure how to spell out the 8kb units, decimal or binary...
Seems easier to just specify the units (which the docs for effective_cache_size says are accepted).
David J.
It does. In a cruel twist of fate, RDS parameter groups do not allow "48GB" and want integer values.
On Wed, Jan 19, 2022 at 1:46 PM David G. Johnston <david.g.johnston@gmail.com> wrote:
On Wed, Jan 19, 2022 at 2:39 PM Wells Oliver <wells.oliver@gmail.com> wrote:Sorry to be daft, but if I want 48GB for effective_cache size, should I put the integer value of 6291456 or 6000000?Not quite sure how to spell out the 8kb units, decimal or binary...Seems easier to just specify the units (which the docs for effective_cache_size says are accepted).David J.
Wells Oliver
wells.oliver@gmail.com
wells.oliver@gmail.com
Re: Setting effective_cache_size in integer form with the 8kb block units
From
"David G. Johnston"
Date:
On Wed, Jan 19, 2022 at 2:57 PM Wells Oliver <wells.oliver@gmail.com> wrote:
It does. In a cruel twist of fate, RDS parameter groups do not allow "48GB" and want integer values.
The system operates and calculates memory in binary per the referenced documentation so 6,291,456 (I double-checked this).
Assuming RDS doesn't do something to that as well...
David J.
"David G. Johnston" <david.g.johnston@gmail.com> writes:
> On Wed, Jan 19, 2022 at 2:57 PM Wells Oliver <wells.oliver@gmail.com> wrote:
>> It does. In a cruel twist of fate, RDS parameter groups do not allow
>> "48GB" and want integer values.
> The system operates and calculates memory in binary per the referenced
> documentation so 6,291,456 (I double-checked this).
If you don't trust hand arithmetic, try
regression=# set effective_cache_size to '48GB';
SET
regression=# select setting from pg_settings where name = 'effective_cache_size';
setting
---------
6291456
(1 row)
regards, tom lane
Thanks all, good to know. Again, apologies for being daft!
On Wed, Jan 19, 2022 at 2:21 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
"David G. Johnston" <david.g.johnston@gmail.com> writes:
> On Wed, Jan 19, 2022 at 2:57 PM Wells Oliver <wells.oliver@gmail.com> wrote:
>> It does. In a cruel twist of fate, RDS parameter groups do not allow
>> "48GB" and want integer values.
> The system operates and calculates memory in binary per the referenced
> documentation so 6,291,456 (I double-checked this).
If you don't trust hand arithmetic, try
regression=# set effective_cache_size to '48GB';
SET
regression=# select setting from pg_settings where name = 'effective_cache_size';
setting
---------
6291456
(1 row)
regards, tom lane
Wells Oliver
wells.oliver@gmail.com
wells.oliver@gmail.com