Re: Crappy performance even though not swapping
От | Richard Broersma Jr |
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Тема | Re: Crappy performance even though not swapping |
Дата | |
Msg-id | 846669.6097.qm@web31809.mail.mud.yahoo.com обсуждение исходный текст |
Ответ на | Crappy performance even though not swapping ("Neil Aggarwal" <neil@JAMMConsulting.com>) |
Список | pgsql-novice |
> I have a Java program that is trying to import over 8 million > rows from a text file. > > When the program starts up, it runs fine, but after a while > it begins to crawl. > > This is usually symptomatic of a machine that started swapping, > but take a look at the attached output from top. > > I am using a LOT of memory, but the swap is still very > low. I don't think the machine should be paging to disk. > > The CPU states show that the cpus are spending most of their time > in an idle state. The process list shows the postmaster and java > processes are less than 10 percent the CPU cycles. > > Having said that, the load average is still about 2. > > Any ideas what could be going on? Your question is a good one for the performance list. From what I've read there, there are a couple of strategies that you can use to improve performance. 1) if you can roll large numbers of insert statements (say 1K to 10K ins/trans) in to single transactions, performance should be helped. 2) If this is a one time insert, you may consider TEMPORARILY turning off fsync and greatly increase your check point segment size for the import. Regards, Richard Broersma Jr.
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