Re: Effects of GUC settings on automatic replans - Mailing list pgsql-hackers

From Jan Wieck
Subject Re: Effects of GUC settings on automatic replans
Date
Msg-id 46016DD6.9060807@Yahoo.com
Whole thread Raw
In response to Effects of GUC settings on automatic replans  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Effects of GUC settings on automatic replans  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On 3/20/2007 1:11 PM, Tom Lane wrote:
> Now that there's a mechanism in the backend that will automatically replan
> queries whenever anything changes about the referenced tables, we have to
> worry about whether an automatic replan might cause surprising changes in
> the behavior of a query.  I looked through the available GUC settings to
> see what would affect a replan, and came up with just four that would
> potentially affect the semantics of the query:
> 
>     search_path
>     add_missing_from
>     transform_null_equals
>     sql_inheritance

Don't we actually store the parsetree in the query cache, and doesn't 
that actually make a lot of the above rather NOT affect the resulting 
plan any more? The objects, used in the parsetree, are identified by OID 
and got only looked up according to the search_path (for example) during 
the initial parsing of the query.


Jan

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