Hi, do you load into the same table that you query? If so, how large (#records) is that table before and after (extra) loading, and do the x values in your table happen to be sorted before the (extra) loading, while they are no no longer after loading, i.e., the newly added (appended) value "destroy" sorted order? Do you load and query in the same transaction, or in different transactions, or do you use autocommit mode for the load? How many queries after loading did you check? Did you wait for some time (say, couple of minutes) after loaading and check how fast the queries are then? And about the loading problems with Feb2010-SP1 & -SP2: Did you file a bug report about that? Thanks! Stefan On Wed, May 19, 2010 at 02:05:59AM -0700, Nozhup wrote:
Loading and querying simultaneously seems to slowdown the database significantly. I can understand if the queries became slower during loading, but it seems that only the first query before loading is finished is slow and all queries coming after.
I can only fix the slowdown by using "killall mserver5" in a terminal, which is not an acceptable solution.
I start 1 "copy into" action with one connection and at the same time a series of simple queries on another connection. The Simple query looks something like this: SELECT x,y FROM table WHERE x = '519';
Used OS: Ubuntu 9.10 and 10.04 MonetDB: Feb2010 release (SP! and SP2 are no option due to them giving loading problems)
Results Query: 1 --> 0.000191 SECONDS : : : Query: 10501 --> 0.000170 SECONDS Query: 10502 --> 0.000169 SECONDS Query: 10503 --> 0.000169 SECONDS Query: 10504 --> 0.000172 SECONDS Query: 10505 --> 0.000172 SECONDS Query: 10506 --> 0.000174 SECONDS Query: 10507 --> 0.000178 SECONDS Query: 10508 --> 1.199149 SECONDS
Load : 1 --> 3.238532 SECONDS
Query: 1-10509 --> 1.238804 SECONDS Query: 1-10510 --> 1.175408 SECONDS Query: 1-10511 --> 1.141172 SECONDS Query: 1-10512 --> 1.132525 SECONDS Query: 1-10513 --> 1.159554 SECONDS Query: 1-10514 --> 1.158303 SECONDS Query: 1-10515 --> 1.160997 SECONDS
How do I solve this or is this an error in MonetDB?
Thanks in advance. -- View this message in context: http://old.nabble.com/Loading-and-querying-on-the-same-database.-tp28605728p... Sent from the monetdb-users mailing list archive at Nabble.com.
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-- | 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) 592-4199 |