about multiprocessingmassdata - Mailing list pgsql-performance

From superman0920
Subject about multiprocessingmassdata
Date
Msg-id 2012040423524938620013@gmail.com
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Responses Re: about multiprocessingmassdata  (Tomas Vondra <tv@fuzzy.cz>)
List pgsql-performance
BLOCKQUOTE {MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; MARGIN-LEFT: 2em } OL {MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px } UL {MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px } P {MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px }
Hi list!
 
i have a table which has 8500000 rows records. i write a java program to update these records.
i use 100 threads to update the records. For example, thread-1 update 1~85000 records; thread-2 update 85001~170000 and so on.
The update sql's aim is remove the space in the column and it is simple: update poi set py=replace(py,' ','') where id=?;
 
By the program log, i find the database of processing data speed so slow, per thread updating 1000 rows need take 260s.
 
BTW:  The PG Server is running on a PC. The PC's total memory is 2G and CPU is "Intel(R) Core(TM)2 Duo E7500 2.93GHz".
When the program's running, CPU just be used 1% and Memory  left 112MB.
 
Is the PC configuration too low cause the problem ?
 
Please help ~~
 
 
Thanks for any tips,

superman0920

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