[MonetDB-users] Query failure with 'recycle' in optimizer

Hi, I have a query that runs without any problems when the default optimizer settings are used. But once I add 'recycle' to the existing optimizer modules, the query doesn't return. Mserver seems to be stuck in an infinite loop with 50% CPU usage. I am running Monet compiled from CVS on Windows. This is the query: select sum(t1."AddressID"), "hour"(t1."ModifiedDate") as aa from "schema1"."CustomerAddress" as t1 inner join "schema1"."CustomerAddress"as t2 on t1."CustomerID" = t2."CustomerID" group by aa This is what I get from 'select opimizer': inline,remap,evaluate,costModel,coercions,emptySet,mitosis,aliases,mergetable,deadcode,constants,commonTerms,joinPath,deadcode,reduce,garbageCollector,dataflow,history,multiplex,recycle Thanks. -- View this message in context: http://www.nabble.com/Query-failure-with-%27recycle%27-in-optimizer-tp233893... Sent from the monetdb-users mailing list archive at Nabble.com.

Alex Bo. wrote:
I have a query that runs without any problems when the default optimizer settings are used. But once I add 'recycle' to the existing optimizer modules, the query doesn't return. Mserver seems to be stuck in an infinite loop with 50% CPU usage.
Does the same thing happen if you disable the mitosis optimiser? Stefan

Hi,
I have a query that runs without any problems when the default optimizer settings are used. But once I add 'recycle' to the existing optimizer modules, the query doesn't return. Mserver seems to be stuck in an infinite loop with 50% CPU usage
Alex Bo. wrote: the recyler optimizer is experimental code !! We would like to hear where the server is spinning. .
I am running Monet compiled from CVS on Windows.
This is the query:
select sum(t1."AddressID"), "hour"(t1."ModifiedDate") as aa from "schema1"."CustomerAddress" as t1 inner join "schema1"."CustomerAddress"as t2 on t1."CustomerID" = t2."CustomerID" group by aa
This is what I get from 'select opimizer':
inline,remap,evaluate,costModel,coercions,emptySet,mitosis,aliases,mergetable,deadcode,constants,commonTerms,joinPath,deadcode,reduce,garbageCollector,dataflow,history,multiplex,recycle
Thanks.

On Tue, May 05, 2009 at 05:16:14PM +0200, Martin Kersten wrote:
Hi,
I have a query that runs without any problems when the default optimizer settings are used. But once I add 'recycle' to the existing optimizer modules, the query doesn't return. Mserver seems to be stuck in an infinite loop with 50% CPU usage
Alex Bo. wrote: the recyler optimizer is experimental code !! We would like to hear where the server is spinning.
preferably by filing a bug report via https://sourceforge.net/tracker/?atid=482468&group_id=56967&func=browse ((for now?) the best way to keep us alert & reminded and to trace the progress ...) Stefan
I am running Monet compiled from CVS on Windows.
This is the query:
select sum(t1."AddressID"), "hour"(t1."ModifiedDate") as aa from "schema1"."CustomerAddress" as t1 inner join "schema1"."CustomerAddress"as t2 on t1."CustomerID" = t2."CustomerID" group by aa
This is what I get from 'select opimizer':
inline,remap,evaluate,costModel,coercions,emptySet,mitosis,aliases,mergetable,deadcode,constants,commonTerms,joinPath,deadcode,reduce,garbageCollector,dataflow,history,multiplex,recycle
Thanks.
------------------------------------------------------------------------------ The NEW KODAK i700 Series Scanners deliver under ANY circumstances! Your production scanning environment may not be a perfect world - but thanks to Kodak, there's a perfect scanner to get the job done! With the NEW KODAK i700 Series Scanner you'll get full speed at 300 dpi even with all image processing features enabled. http://p.sf.net/sfu/kodak-com _______________________________________________ MonetDB-users mailing list MonetDB-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/monetdb-users
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Hi Alex, as a beginning can you move the recycle optimizer *before* GarbageCollector in the optimizer list? The recycler is designed to collect intermediates before they are garbage-collected. As Martin said it is an experimental code and they might be other pitfalls, esp. under Windows. Please, keep us informed. Regards, Milena
On Tue, May 05, 2009 at 05:16:14PM +0200, Martin Kersten wrote:
Hi,
I have a query that runs without any problems when the default optimizer settings are used. But once I add 'recycle' to the existing optimizer modules, the query doesn't return. Mserver seems to be stuck in an infinite loop with 50% CPU usage
Alex Bo. wrote: the recyler optimizer is experimental code !! We would like to hear where the server is spinning.
preferably by filing a bug report via https://sourceforge.net/tracker/?atid=482468&group_id=56967&func=browse
((for now?) the best way to keep us alert & reminded and to trace the progress ...)
Stefan
I am running Monet compiled from CVS on Windows.
This is the query:
select sum(t1."AddressID"), "hour"(t1."ModifiedDate") as aa from "schema1"."CustomerAddress" as t1 inner join
"schema1"."CustomerAddress"as
t2 on t1."CustomerID" = t2."CustomerID" group by aa
This is what I get from 'select opimizer':
inline,remap,evaluate,costModel,coercions,emptySet,mitosis,aliases,mergetable,deadcode,constants,commonTerms,joinPath,deadcode,reduce,garbageCollector,dataflow,history,multiplex,recycle
Thanks.
------------------------------------------------------------------------------ The NEW KODAK i700 Series Scanners deliver under ANY circumstances! Your production scanning environment may not be a perfect world - but thanks to Kodak, there's a perfect scanner to get the job done! With the NEW KODAK i700 Series Scanner you'll get full speed at 300 dpi even with all image processing features enabled. http://p.sf.net/sfu/kodak-com _______________________________________________ MonetDB-users mailing list MonetDB-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/monetdb-users
-- | Dr. Stefan Manegold | mailto:Stefan.Manegold@cwi.nl | | CWI, P.O.Box 94079 | http://www.cwi.nl/~manegold/ | | 1090 GB Amsterdam | Tel.: +31 (20) 592-4212 | | The Netherlands | Fax : +31 (20) 592-4312 |
------------------------------------------------------------------------------ The NEW KODAK i700 Series Scanners deliver under ANY circumstances! Your production scanning environment may not be a perfect world - but thanks to Kodak, there's a perfect scanner to get the job done! With the NEW KODAK i700 Series Scanner you'll get full speed at 300 dpi even with all image processing features enabled. http://p.sf.net/sfu/kodak-com _______________________________________________ MonetDB-users mailing list MonetDB-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/monetdb-users

Disabling 'mitosis' didn't help,but moving the recycler ahead of the garbage collector did the job. The query now returns. However, I do not notice any speedup in recurrent executions of the same query, which was what I expected from enabling the recycler. Am I right in expecting that? Thanks. -- View this message in context: http://www.nabble.com/Query-failure-with-%27recycle%27-in-optimizer-tp233893... Sent from the monetdb-users mailing list archive at Nabble.com.
participants (5)
-
Alex Bo.
-
Martin Kersten
-
Milena.Ivanova@cwi.nl
-
Stefan de Konink
-
Stefan Manegold