Re: Using a postgres table to maintain unique id?

On Mon, 13 Nov 2000 10:44:21 -0700, Steve Wampler said:

> Poet/Joshua Drake wrote:
> >
> > >However, I also use Postgres (7.0.2) throughout this
> > >application and it seems cleaner to me to keep the current
> > >id value in a table and just use postgres to provide access
> > >(with a trigger function to increment the id on access).
> >
> > Why not a sequence?
>
> Can someone show me how to create (and use) an int8 sequence?
>

create sequnece seq_name ;

there are additional options
start sql and type
drfrog=# \h create sequence
Command: CREATE SEQUENCE
Description: Creates a new sequence number generator
Syntax:
CREATE SEQUENCE seqname [ INCREMENT increment ]
[ MINVALUE minvalue ] [ MAXVALUE maxvalue ]
[ START start ] [ CACHE cache ] [ CYCLE ]
drfrog=#

more info in the docs too!

> > >Is this reasonable? Is it fast? (I need 10 or more IDs
> > >generated each second.) Can I avoid having the table
> > >gradually fill with "old" rows for this entry, and this
> > >avoid the need to run VACUUM ANALYZE periodically?
> >
> > The only problem I have had with this type of thing is when a number gets
> > deleted, it does not get recycled.
>
> Fortunately, I don't want any number to ever get recycled - the id needs to
> be unique throughout the 25+ year lifetime of the project. The table
> would have a single row with a single column. Selecting that table cell
> would return the current value, but leave the value incremented in the
> table cell (it's ok if it increments the value before returning).
>
>
> --
> Steve Wampler- SOLIS Project, National Solar Observatory
> swampler(at)noao(dot)edu
>
>