On 1/30/23 11:43, veem v wrote:
> Thank You So much for the details. I am a bit new to postgres. And these
> test results I picked were from a dev system. If I understand it
> correctly, do you mean these settings(usage of C locale or "native"
> 16-byte uuid) which you mentioned should be there in a production system
> and thus we should test the performance of the UUID vs sequence on a
> similar setup? Or say if this sort of degradation of UUID performance is
> not expected then , how to get these settings tweaked ON, so as to see
> the best string type or UUID performance, can you please guide me here?
No what is being said is change:
source_id varchar(36)
to
source_id uuid
as i:
https://www.postgresql.org/docs/current/datatype-uuid.html
>
> On Mon, 30 Jan 2023 at 22:18, Tom Lane <tgl@sss.pgh.pa.us
> <mailto:tgl@sss.pgh.pa.us>> wrote:
>
> Dominique Devienne <ddevienne@gmail.com
> <mailto:ddevienne@gmail.com>> writes:
> > On Mon, Jan 30, 2023 at 5:11 PM veem v <veema0000@gmail.com
> <mailto:veema0000@gmail.com>> wrote:
> >> CREATE TABLE test1_UUID ( id bigint,source_id varchar(36)
> PRIMARY KEY, Name varchar(20) );
>
> > Maybe if you used a "native" 16-byte uuid, instead of its textual
> > serialization with dashes (36 bytes + length overhead), the gap would
> > narrow.
>
> Yeah, especially if your database is not using C locale. The
> strcoll or ICU-based comparisons done on string types can be
> enormously more expensive than the memcmp() used for binary
> types like native uuid.
>
> regards, tom lane
>
--
Adrian Klaver
adrian.klaver@aklaver.com
