Re: query progress indicator - Mailing list pgsql-general

From Alex Satrapa
Subject Re: query progress indicator
Date
Msg-id 40272B60.1000603@lintelsys.com.au
Whole thread Raw
In response to query progress indicator  (David Garamond <lists@zara.6.isreserved.com>)
List pgsql-general
David Garamond wrote:
> [=============>           ] 56% ETA ...
>
> I know there is no such thing in Postgres right now (though there is
> pg_stat_activity). But is there database product that can do this?

Well... you could do something it in PostgreSQL.  If it's the recovery of the data that's causing selects to go for too
longwithout feedback, simply open a cursor and increment the progress bar as you bring result back from the cursor. If
it'sthe query itself, break it up into smaller pieces. 

If there are a bunch of changes to be done, try increasing the number of inserts/updates by making the criteria more
specific,eg: instead of 'where date between '2004-01-01' and '2004-01-31', break it up into one day at a time. Then you
canmeasure progress by the number of updates that have completed. 

For longer or larger change sets, you have to address the issue of knowing how many changes are actually going to be
madewithout actually performing the query - witness the difference between "explain" and "explain analyze" :) 

These are just my ideas for doing things from the application side of things. Perhaps they might be of some use.

Alex Satrapa


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