Re: SQL design pattern for a delta trigger? - Mailing list pgsql-general

On Dec 7, 2007, at 11:42 AM, Colin Wetherbee wrote:

> You can do this with a conditional.  Something like the following
> should work.
>
> IF
>  NOT (a query matching your data returns rows)
> THEN
>  INSERT (your new data)

There exists a race condition here unless you've locked your tables.