sysptprof

I am writing some benchmark scripts to keep track of chunk and table IO. According to the manual, the following is true about sysmaster:sysptprof The sysptprof table lists information about a tblspace. Tblspaces correspond to tables. Profile information for a table is available only when a table is open. When the last user who has a table open closes it, the tblspace in shared memory is freed, and any profile statistics are lost. I decided to test this. I went to a quiet database, zero'd the stats, selected from sysptprof where tabname='x'. Got all zeros. Then I did some reads to the table in dbaccess. Did the sysptprof query again, and got numbers. Closed the dbaccess session. The numbers still existed in sysptprof. I did this test numerous ways, using exsql from command line etc... Each time I do some more reads, the numbers accumulate in sysptprof, until I zero the stats. This goes against what the manual says. Dont get me wrong, I am happy about this, because I only want to collect io stats by table once a day. But I just want to ask about it to make sure I'm not fooling myself here. My conclusion is that sysptprof doesn't clear until stats are zerod. Is this correct ? Thanks, Floyd ======================== -<<Floyd Wellershaus>>- Database Administrator Unix Administrator email: fwellers@yahoo.com Home: 703-430-0805 Cell: 703-477-6045 ======================== http://www.one.org/

Floyd Wellershaus wrote: > I am writing some benchmark scripts to keep track of chunk and table IO. > According to the manual, the following is true about sysmaster:sysptprof > > > The *sysptprof* table lists information about a tblspace. Tblspaces > correspond to tables. > > Profile information for a table is available only when a table is open. > When the last user who has a table open closes it, the tblspace in > shared memory is freed, and any profile statistics are lost. <SNIP> IB that the table remains 'open' as long as there are pages from the table in the buffer cache. Once the pages have aged out of the cache then the table should close and the stats would be lost. You can test this by doing your initial reads, then close that session and leave the table alone for a while, then read more pages from some other table than there are cache pages to force the table's pages out of the cache (you can check with onstat -P to make sure that all pages from the table's and its index's partnums are gone). Art S. Kagel

Floyd Wellershaus wrote: > I am writing some benchmark scripts to keep track of chunk and table IO. > According to the manual, the following is true about sysmaster:sysptprof > > > The *sysptprof* table lists information about a tblspace. Tblspaces > correspond to tables. > > Profile information for a table is available only when a table is open. > When the last user who has a table open closes it, the tblspace in > shared memory is freed, and any profile statistics are lost. <SNIP> IB that the table remains 'open' as long as there are pages from the table in the buffer cache. Once the pages have aged out of the cache then the table should close and the stats would be lost. You can test this by doing your initial reads, then close that session and leave the table alone for a while, then read more pages from some other table than there are cache pages to force the table's pages out of the cache (you can check with onstat -P to make sure that all pages from the table's and its index's partnums are gone). Art S. Kagel