Thanks Tomas! I will try. Regards, Uday
On Tue, Oct 30, 2018 at 6:43 PM Tomas Vondra <tomas.von...@2ndquadrant.com> wrote: > I don't think PostgreSQL has anything like that at the moment. It would > not be difficult to tweak the UUID generator to generate sequential (or > monotonic) values, the tricky part seems to be durability requirements. > > One idea would be to simply store the value in (shared) memory, but that > would mean losing the state on restart/crash, so there would need to be > some sort of protection against generating duplicate values (say, using > postmaster timestamp as the first 64 bits of the UUID). > > Another idea is to piggy-back this on bigint sequence somehow - split > the 128bit range into 64+64, use the sequence value for the first 64b > and pick the other half by random. That would guarantee both uniqueness, > monotonicity and durability. And it would also be fairly random, making > it difficult to guess UUIDs. > > regards > > On 10/29/2018 04:06 PM, Uday Bhaskar V wrote: > > Hi, > > > > We have migrated from Oracle to Postgres, there because of the > > replication requirements we used UUID columns. > > 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 > > need similar functionality here. > > I want to create a function which generates a sequential UUIDs, Any > > suggestions or support would be much appreciated. > > > > Thanks, > > Uday > > -- > Tomas Vondra http://www.2ndQuadrant.com > PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services >
