Subject: Re: Serial
From: Scott Marlowe <smarlowe@g2switchworks.com>
To: Shavonne Marietta Wijesinghe <shavonne.marietta@studioform.it>
Cc: pgsql-sql@postgresql.org
In-Reply-To: <008301c775d1$4b224420$1102a8c0@dream>
References: <008301c775d1$4b224420$1102a8c0@dream>
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Date: Tue, 03 Apr 2007 09:17:19 -0500

On Tue, 2007-04-03 at 04:20, Shavonne Marietta Wijesinghe wrote:
> Ok so i'm posting alot in the forums. Anyway for a change i have
> another problem ^___^
>  
> I have a table that has a field n_gen serial NOT NULL
>  
> ermm let me explain. I have 5 records inserted (n_gen = 1, 2, 3, 4, 5)
>  
> At a surtain point i DELETE the record 2 and UPDATE the record 5 with
> the n_gen 2. So now i have 4 records (n_gen = 1, 2 (EX 5), 3, 4)  Upto
> this point i'm ok. 
>  
> The problem is when i INSERT a new record. It takes the value n_gen =
> 6 but i need it to take the value 5. It keeps a record of the delete
> records.
>  
> Is there anyway in PostgreSQL i can change it? or another progressive
> that i can use for n_gen ??

Yes there is, and you generally shouldn't do it.  There are issues with
race conditions and misreferenced data that can happen when you try to
reuse sequence numbers.

Sadly, some poorly defined business processes require this.

Are you required to have sequential numbers, or is just something that
feels good / looks good?