Re: Progress indication prototype

Robert Haas <robertmhaas@gmail.com>

From: Robert Haas <robertmhaas@gmail.com>
To: Peter Eisentraut <peter_e@gmx.net>
Cc: Itagaki Takahiro <itagaki.takahiro@gmail.com>, pgsql-hackers@postgresql.org
Date: 2010-09-16T19:56:40Z
Lists: pgsql-hackers
On Thu, Sep 16, 2010 at 2:52 PM, Peter Eisentraut <peter_e@gmx.net> wrote:
>> > a very simple query.
>>   SELECT * FROM tbl;
>> can report reasonable progress, but
>>   SELECT count(*) FROM tbl;
>> cannot, because planned_tuple_count of the aggregation is 1.
>> I hope better solutions for the grouping case because they are used
>> in complex queries, where the progress counter is eagerly wanted.
>
> I think that's a problem for a later day.  Once we have the interfaces
> to report the progress, someone (else) can investigate how to track
> progress of arbitrary queries.

I reiterate my earlier criticism of this whole approach: it seems to
assume that computing query progress is something inexpensive enough
that we can afford to do it regardless of whether anyone is looking.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise Postgres Company