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@noao.edu
>  
>