September 2011 - users-list

[MonetDB-users] Parallel COPY INTO
by zack_pcd 22 Sep '11

22 Sep '11

I have a large table with about 50 billion records. The files to be loaded are not in CSV format. The files are processed in java and the data uploaded to the database using COPY INTO through the MapiSocket interface. I do not have the record count readily available. My question is this: If I open multiple MapiSockets and upload multiple streams of data at the same time to the same table, is this supported and stable? I am asking because the database appears to become unresponsive after the … [View More]

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[MonetDB-users] Partitioning on Monetdb
by Benji07 21 Sep '11

21 Sep '11

Does Monetdb supports basic table partitioning using MAPI? I need to split one large table into smaller physical pieces and improve query performance. I didn't find help in documentation. Thanks for help -- View this message in context: http://old.nabble.com/Partitioning-on-Monetdb-tp32493404p32493404.html Sent from the monetdb-users mailing list archive at Nabble.com.

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[MonetDB-users] EPS / SVG of new MonetDB logo
by Stefan de Konink 20 Sep '11

20 Sep '11

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 Hi, The new logo is online on the new website for a while now, is there any EPS/SVG or other vector format available? Stefan -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEAREKAAYFAk547rYACgkQYH1+F2Rqwn14VwCgioRrllvOlEUwHJke6eLxdXca rm0An2CwkBr1KoUWmgYewB64U5B49GtS =ef+A -----END PGP SIGNATURE-----

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[MonetDB-users] GUID
by Michal Dvorak 20 Sep '11

20 Sep '11

Hi MonetDB-Team, are you going to implement 128b GUID? If not, any idea how to bypass it? 2x Int64 or BLOB(128)? Thank you very much for your answer J Best regards, Michal

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[MonetDB-users] Maximum Parallelism and Recommended Hardware for MonetDB
by brien colwell 20 Sep '11

20 Sep '11

I set up a MonetDB server for a data mining team on a single node. The node's specs are 32 cores (4x8 AMD 2.3GHz) 128GiB RAM, with the dbfarm on a RAID0 2xSSD (I think they are Intel SSDs). MonetDB on this hardware works well for aggregates and joins on integers, but chugs considerably on inline views with strings and joins with strings. The team usually has 2-3 concurrent jobs at any given time, some materializing new tables, with lots of bulk loading ("copy into ... from file ..."). A typical … [View More]

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[MonetDB-users] How to compress a table
by Alexis Berlemont 20 Sep '11

20 Sep '11

Hi, I am currently trying to evaluate MonetDB as a solution to hold significant amounts of data. Because of limited storage capacities, I am trying to enable compression in MonetDB. I did not manage to find any tutorial on that subject, so I did not go very far. I cannot even tell that I wholly understand the problem. According to the page "Documentation->User Guide->compression", I understood that I had to inject a compression optimizer inside a pipeline. This "thing" is supposed to … [View More]

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[MonetDB-users] How to change in/out date format
by Eugene Prokopiev 20 Sep '11

20 Sep '11

Hi, is it possible to use "yy-MM-dd HH:mm:ss.SSS" date format via something like SET DATESTYLE in COPY INTO ... FROM ... with mclient to reuse existing files? -- Thanks, Eugene Prokopiev

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[MonetDB-users] query time
by anagnostes 20 Sep '11

20 Sep '11

Hi. I would like to know if it's possible to get the query time using the input "\<file" and redirecting the output to "\>file" in Windows. When i use the input file it nevers throws the query time. So i can't know it. Thank you. -- View this message in context: http://old.nabble.com/query-time-tp32232809p32232809.html Sent from the monetdb-users mailing list archive at Nabble.com.

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[MonetDB-users] Memory leaks in the latest trunk?
by Stefan de Konink 20 Sep '11

20 Sep '11

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 Hello, Recently I decided it was again a good idea(tm) to 'test' the latest MonetDB trunk on an updated dataset. Sadly over the last 6 days I observed a growing memory usage, today resulting in a segmentation fault. For now nothing more than mserver5[26142]: segfault at 8 ip 00007f1e1e592a31 sp 00007f1e00ca63b8 error 4 in libc-2.13.so[7f1e1e515000+17d000] is known to me, which is development wise totally useless. But an other question did … [View More]

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[MonetDB-users] count slower than expected?
by Joris Slob 20 Sep '11

20 Sep '11

Hello mailing list! This is my first attempt to ask a question here, so please excuse my ignorance. For large tables (>1M rows), I encounter strange behavior when using the COUNT function in SQL in the mclient. When I do the following query: SELECT DISTINCT(predicate) FROM facts; I get a nice resultset of 31 tuples in 20ms. When I try the following query: SELECT COUNT(DISTINCT(predicate)) FROM facts; I get my answer in 565ms. It seems weird that the database doesn't 'optimize' this … [View More]

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