October 2010 - users-list

[MonetDB-users] upgrade notes: Feb2010 --> Jun2010
by Mark Bucciarelli 07 Oct '10

07 Oct '10

Hi, I'd like to upgrade to the June release. I'm running Feb 2010. Can I just build the June release and expect it will just work with my database? Or do I need to upgrade the data somehow? I poked around dev.monetdb.org/hg, looking for release notes, changelist, etc. but didn't find anything. Thanks, m

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[MonetDB-users] bug #2634 in Jun2010? [was: upgrade notes: Feb2010 --> Jun2010]
by Mark Bucciarelli 07 Oct '10

07 Oct '10

On Thu, Oct 7, 2010 at 9:15 AM, Sjoerd Mullender <sjoerd(a)acm.org> wrote: > On 2010-10-07 14:41, Mark Bucciarelli wrote: > >> I poked around dev.monetdb.org/hg, looking for release >> notes, changelist, etc. but didn't find anything. > > http://monetdb.cwi.nl/Development/Releases/Jun2010/ > Thanks. Was the commit in bug #2634 in the release? I don't see it in the SQL notes. He closed as NEEDS MORE INFO (I think---I can't tell from ticket history) because I did not include a test case. But he did commit some change that fixed the issue (I was able to upload a test case this week, and verified his fix solved my case). Thanks, m http://bugs.monetdb.org/show_bug.cgi?id=2634

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[MonetDB-users] Performance improvements over equal queries limits to operators?
by Stefan de Konink 06 Oct '10

06 Oct '10

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 Hello, I was quite surprised about the performance of some queries, that I expected to be heavy weighted, but actually performed pretty well. To show some things: sql>select * from kvk where postcode like '2265CA' and adres like '%7%'; 3 tuples (259.000ms) sql>select * from kvk where postcode like '2265CA' and adres like '%7%'; 3 tuples (259.000ms) sql>select * from kvk where postcode like '2265CA' and adres like '%7%'; 3 tuples (258.000ms) sql>select * from kvk where postcode like '2265CA' and adres like '%7%'; 3 tuples (257.000ms) sql>select * from kvk where postcode = '2265CA' and adres like '%7%'; 3 tuples (11.000ms) sql>select * from kvk where postcode = '2265CA' and adres like '%7%'; 3 tuples (6.000ms) sql>select * from kvk where postcode = '2265CA' and adres like '%7%'; 3 tuples (6.000ms) sql>select * from kvk where kvk = 273121520000; 1 tuple (473.000ms) sql>select * from kvk where kvk = 273121520000; 1 tuple (5.000ms) I wonder: what makes the 11ms to 6ms possible in the like vs = scenario? While a repeat of the like operator itself doesn't give a true improvement? As you can observe the like argument doesn't have any modifiers, so it should actually become a normal equal. (I noticed this later, goes beyond my original point, will file a bug for enhancement.) Also I'm quite surprised that the primary key lookup still takes a fair amount of time, could be i/o related obviously, but the performance on the second run is again huge, even for other arguments. Stefan -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.16 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEAREKAAYFAkysWw8ACgkQYH1+F2Rqwn19AgCgk9lkRBLcWdylxxz9M4B8a8f5 5JUAn1TOU1VxpvVfVWJMLwlwp9Pz4a0x =IqCY -----END PGP SIGNATURE-----

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[MonetDB-users] Dump schema w/ mclient?
by Mark Bucciarelli 05 Oct '10

05 Oct '10

Is there a way to user mclient to dump the db schema without dumping the data? I tried creating a one line SQL file with \d <tablename> and piping to mclient stdin, but it didn't work. Thanks, m

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[MonetDB-users] add a unique constraint, need to create index?
by Mark Bucciarelli 04 Oct '10

04 Oct '10

Hi, I added a unique constraint on two fields, and noticed there was not an index created on those two fields. Do I need to do a CREATE INDEX or is it implicit? I will be using those two fields a lot in WHERE clauses. Thanks, m

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[MonetDB-users] Large XML instances with MonetDB/XQuery 4.38.5
by Christian Grün 02 Oct '10

02 Oct '10

Hi everyone, is it still possible to shred large XML instances with MonetDB/XQuery, or do I need more memory for shredding? I was just trying to the 1GB instance of XMark with WinXP 32Bit and 2GB RAM, and this is what I got: MonetDB>shred_doc("1gb.xml", "xmark"); #GDKmmap(536870912) fails, try to free up space [memory in use=36143780,virtual memory in use=1015480320] #GDKmmap(536870912) result [mem=26016940,vm=1005387776] !ERROR: [shred_url]: 1 times inserted nil due to errors at tuples 0@0. !ERROR: [shred_url]: first error was: !ERROR: HEAPextend: failed to extend to 536870912 for 06\632theap !ERROR: shredBAT_append_str: APPEND-STR[_prop_text]( follow murders prov shoes p resent eager delivered defy bend viol here marquis powers complexion pillar cran ts agate ), BUNappend fails !ERROR: CMDshred_url: operation failed. pf:add-doc(...) produces the same output; the XML document itself is well-formed. Thanks, Christian

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