Thread: PostgreSQL database segsize
Hi,
If you are building a Postgresql database from source and you use option --with-segsize=4, how do you verify that the database segsize is 4GB and not the default 1GB? Is there a query that you can run?
Or even if you come into a place to support an existing PostgreSQL database, how do you find out what the database segsize is?
Thanks in advance for your help.
-- Bill
On Tue, Jun 30, 2020 at 12:17 AM Bill Glennon <wglennon@gmail.com> wrote:
Hi,If you are building a Postgresql database from source and you use option --with-segsize=4, how do you verify that the database segsize is 4GB and not the default 1GB? Is there a query that you can run?Or even if you come into a place to support an existing PostgreSQL database, how do you find out what the database segsize is?
You can run the query "SHOW segment_size" to show the compiled-in value.
Awesome! That worked. Thank you Magnus!
I should have thought of that earlier. LOL
On Mon, Jun 29, 2020 at 6:33 PM Magnus Hagander <magnus@hagander.net> wrote:
On Tue, Jun 30, 2020 at 12:17 AM Bill Glennon <wglennon@gmail.com> wrote:Hi,If you are building a Postgresql database from source and you use option --with-segsize=4, how do you verify that the database segsize is 4GB and not the default 1GB? Is there a query that you can run?Or even if you come into a place to support an existing PostgreSQL database, how do you find out what the database segsize is?You can run the query "SHOW segment_size" to show the compiled-in value.--
Magnus Hagander <magnus@hagander.net> writes:
> On Tue, Jun 30, 2020 at 12:17 AM Bill Glennon <wglennon@gmail.com> wrote:
>> If you are building a Postgresql database from source and you use
>> option --with-segsize=4, how do you verify that the database segsize is 4GB
>> and not the default 1GB? Is there a query that you can run?
> You can run the query "SHOW segment_size" to show the compiled-in value.
pg_controldata will show it too, though a bit more opaquely:
Blocks per segment of large relation: 131072
This would be helpful if you have an on-disk database and no running
server.
regards, tom lane