Re: Indexes on UUID - Fragmentation Issue

[MichaelDBA <MichaelDBA@xxxxxxxxxxx>]

or prepend the UUID with a timestamp?

Regards,
Michael Vitale

Andreas Karlsson

Monday, October 29, 2018 10:52 AM

On 10/29/2018 02:29 PM, Uday Bhaskar V wrote:> I have

How is it implemented? I can personally see two ways of generating sequential UUID:s. Either you use something like PostgreSQL's sequences or you can implement something based on the system time plus some few random bits which means they will be mostly sequential.

It could be worth checking on the hackers mailing list if there is any interest in this feature, but if it works like a sequence it should also probably be a sequence if it is ever going to be accepted into the core.

For your own use I recommend doing like Merlin suggested and write an extension. As long as you know a bit of C they are easy to write.

Andreas

Uday Bhaskar V

Monday, October 29, 2018 9:29 AM

Hi,

I have searched in many postgres blogs for Sequential UUID generation, which can avoid Fragmentation issue.

I did a POC(in postgres) with sequential UUID against Non sequential which has shown lot of different in space utilization and index size. Sql server has "newsequentialid" which generates sequential UUID. I have created C function which can generate a sequential UUID, but I am not sure how best I can use that in postgres.

I would really like to contribute to Postgres, If I can. Please let me know your thoughts or plans regarding UUID generation.

Regards,

Uday