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

[Greg Williamson]

Rob --

<...>
>
>Thanks,
>
>my version is 8.4. The table contains strings but are not too long...under 100char.
>
>Thanks,
>


According to <http://trac.osgeo.org/postgis/wiki/DevWikiPostGISCoding>:

"All PostGIS objects are "varlena", they don't have a fixed size. ..."

So maybe you got some large geometries that triggered TOAST processing ?

Greg W.

>
>________________________________
>Von: Greg Williamson <gwilliamson39 at yahoo.com>
>An: Robert Buckley <robertdbuckley at yahoo.com>; "postgis-users at postgis.refractions.net" <postgis-users at postgis.refractions.net>; PostGIS Users Discussion <postgis-users at postgis.refractions.net>
>Gesendet: 21:19 Donnerstag, 22.September 2011 
>Betreff: Re: [postgis-users] where did pg_toast,pg_toast_temp1 come from?
>
>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
>
>
>
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>>