Re: OLAP CUBE/ROLLUP Operators and GROUP BY grouping sets - Mailing list pgsql-hackers

From Robert Bedell
Subject Re: OLAP CUBE/ROLLUP Operators and GROUP BY grouping sets
Date
Msg-id 200312172325823.SM00984@xavier
Whole thread Raw
In response to Re: OLAP CUBE/ROLLUP Operators and GROUP BY grouping sets  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
Thanks for the pointers!
> > The documentation points to the
> > 'sort_mem' parameter for this, but the code doesn't look to actually
> > implement that yet.
> 
> Well, yeah, that's sort of exactly the point ... it's considered during
> planning but the executor code has no fallback if the planner guesses
> wrong.

Yep.  The doc is wishful thinking then ;)  I was just verifying that.
> > 4) Should LookupTupleHashEntry() be worried about the pointers it
> > receives...similarly for hash_search()?

Was wondering how safe it was to write hashed data to disk.. given your
suggestions (and the obvious necessity) pretty safe, but it requires some
handling.  My bad.

Cheers!

Robert




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