Hi Ivan, What do you mean by:
"Performance degrades in some situations when you run parallel transactions which extensively use IO. " Is it typical to see 25% performance with 2 threads? I wouldn't expect 2 threads to degrade in performance in typical usages. Ming - what kinds of queries are these thread doing? Thanks, Mark On Mon, Jan 26, 2009 at 4:37 PM, Ivan Shcheklein <[email protected]> wrote: > Hi Ming, > > >> The number is connected with the main memory. >> We have totally 16 GB memory, but wir can only set the number up to max. >> 30000. >> How can we increase the -bufs-num setting in our case? > > > Sedna is a 32-bit application. It means that it can't allocate more than > 2-3GB (exact number may vary depending on system configuration). > Are you sure you need buffer memory larger than 2GB (bufs-num equals 32000)? > > >> >> In our experience concurrent access in the same collection causes >> performance issurs. The access with 2 threads has just 20%-25% performance >> as with 1 thread. >> Is this a known issue? > > It depends on queries you run. > However, at the moment Sedna has a bottleneck in se_sm (database instance > process). Performance degrades in some situations when you run parallel > transactions which extensively use IO. > > >> >> The speed of insert a document as xml depends on the amount of documents >> in the collection. To insert a document with 1.5 KB, it takes >> 30ms (7,000docs)/100ms(230,000docs)/730ms(660,000docs). >> Is this expected? > > We will try to reproduce this issue. I'll let you know. > > >> We are looking for a way to improve the performance. If there is no way >> to increase the speed of insert a xml document, we have to reorganise >> our data(expected ca. 5,000,000 docs), so that, there are more >> collections or sub-collections with fewer data in them. > > > I think, you can use sub-collections, or even start multiple databases. > If you are going to use multiple collections you probably need to increase > persustent heap size (see se_cdb options). > > > Ivan Shcheklein, > Sedna Team > > > ------------------------------------------------------------------------------ > This SF.net email is sponsored by: > SourcForge Community > SourceForge wants to tell your story. > http://p.sf.net/sfu/sf-spreadtheword > _______________________________________________ > Sedna-discussion mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/sedna-discussion > > ------------------------------------------------------------------------------ This SF.net email is sponsored by: SourcForge Community SourceForge wants to tell your story. http://p.sf.net/sfu/sf-spreadtheword _______________________________________________ Sedna-discussion mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/sedna-discussion
