[postgis-users] where did pg_toast,pg_toast_temp1 come from?

[Greg Williamson]

Rob -- 

>Hi,
>
>
>when I left work today these pg_toast tables were not in my database. when I looked later ther were.
>
>
>Can anyone tell me where they came from and why they are automatically created in every database?
>


You don't state what version of postgres this happens on, but in general TOAST tables are created by the system to hold long compressed values (typically text aka varlena tables). I think you can turn this facility off, but in general postgres will try to take very long strings, for example, and compress them, putting them into a toast table to that the row size of the original table doesn't grow excessively. See, for example, 
 <http://www.postgresql.org/docs/9.0/interactive/storage-toast.html>

So I suspect what happened is that someone entered some long text values and postgres created the toast tables to handle these long strings.

HTH,

Greg Williamson