Re: System catalog bloat removing safety

Hi,

On 2013-09-17 23:12:24 -0700, Sergey Konoplev wrote:
> How safe is it to use the technique described by the link below with
> system catalog tables to remove bloat?
> 
> (in a couple of words it is about moving tuples to the beginning of
> the table with a special way of updating)
> 
> http://www.depesz.com/2010/10/17/reduce-bloat-of-table-without-longexclusive-locks/
> 
> Are there any caveats?

At least for pg_index it's not safe, we use the xmin of rows when
indcheckxmin = true.
I am not aware of other cases, but I'd be hesitant to do so.

You have bloat because of lots of temporary tables IIRC?

Greetings,

Andres Freund

-- Andres Freund                       http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
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