Thanks，professor Stefan Manegold,when I use explain,I get the optimizer MAL plan. I have another question, so we know that many classic optimizer for row-oriented database，and can I say the MAL optimizer is unique for column-oriented database such as MonetDB? or some of MAL optimizer is unique for column-oriented? Best regards!
2010/8/11 Stefan Manegold <stefan.maneg...@cwi.nl> > On Wed, Aug 11, 2010 at 04:23:42PM +0800, kun ren wrote: > > I read sql_optimizer setting in monetdb5.conf ,and default setting is: > > sql_optimizer=default_pipe > > > default_pipe=inline,remap,evaluate,costModel,coercions,emptySet,aliases,mitosis,mergetable,deadcode,commonTerms,joinPath,reorder,deadcode,reduce,garbageCollector,dataflow,history,multiplex > > > > so there are many optimizer,but why when i debug MonetDB,and dump the mal > of > > my sql statement,but i can't find the optimizer mal ,and don't enter > the > > optimizer? like there are no optimizer, > > if you prefix your SQL query with EXPLAIN to see the MAL plan, you get the > optimizer MAL plan, i.e., all optimizers have already been called and done > their work. > > Stefan > > > > > 2010/8/11 Stefan Manegold <stefan.maneg...@cwi.nl> > > > > > Yes, if you write MAL "by hand" (or have some program create it) that > does > > > explicitly call a MAL optimizer, that MAL optimizer is indeed used to > > > optimize the MAL code according to its very purpose. > > > > > > Stefan > > > > > > On Wed, Aug 11, 2010 at 03:49:47PM +0800, kun ren wrote: > > > > It is only used by SQL? and how to designation the optimiser？but when > I > > > > write MAL,for example, > > > > i:=0; > > > > b:= "done"; > > > > barrier go:= true; > > > > c:=i+1; > > > > d:="step"; > > > > v:=d; > > > > io.print(v); > > > > i:=c; > > > > redo go:= i<2; > > > > exit go; > > > > io.print(b); > > > > optimizer.aliasRemoval(); > > > > > > > > the last optimizer.aliasRemoval() is used for optimizing? > > > > > > > > 2010/8/11 Fabian Groffen <fabian.grof...@cwi.nl> > > > > > > > > > On 11-08-2010 15:25:15 +0800, kun ren wrote: > > > > > > Recently,I am intersting in MAL optimize，and have read the > manual > > > of > > > > > the > > > > > > MAL optimize, but it is so long, Possible if we want to use mal > > > optimize > > > > > ,we > > > > > > must degignation the optimize consideration, such as alias > > > removal, > > > > > > constant expression,join path optimizer;And then I dedug the > > > MonetDB,but > > > > > > default it don't use any optimize.so what do you think about the > mal > > > > > > optimize? > > > > > > > > > > It is only used when you use SQL. The sql_optimizer setting in > > > > > monetdb5.conf controls which optimisers are run, which by default > are > > > > > quite a few. > > > > > > > > > > > > > > > > > > > ------------------------------------------------------------------------------ > > > > > This SF.net email is sponsored by > > > > > > > > > > Make an app they can't live without > > > > > Enter the BlackBerry Developer Challenge > > > > > http://p.sf.net/sfu/RIM-dev2dev > > > > > _______________________________________________ > > > > > Monetdb-developers mailing list > > > > > Monetdb-developers@lists.sourceforge.net > > > > > https://lists.sourceforge.net/lists/listinfo/monetdb-developers > > > > > > > > > > > > > > > > ------------------------------------------------------------------------------ > > > > This SF.net email is sponsored by > > > > > > > > Make an app they can't live without > > > > Enter the BlackBerry Developer Challenge > > > > http://p.sf.net/sfu/RIM-dev2dev > > > > > > > _______________________________________________ > > > > Monetdb-developers mailing list > > > > Monetdb-developers@lists.sourceforge.net > > > > https://lists.sourceforge.net/lists/listinfo/monetdb-developers > > > > > > > > > -- > > > | Dr. Stefan Manegold | mailto:stefan.maneg...@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) 592-4199 | > > > > > -- > | Dr. Stefan Manegold | mailto:stefan.maneg...@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) 592-4199 | >
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