how to use onstat -P

How to use onstat -P(not -p) to tell informix server's performance question:? -- Posted via http://dbforums.com

On Sun, 26 Oct 2003 21:32:56 -0500, dusong wrote: There are three areas of interest on an onstat -P report. 1) The first line: Looking at the partnum zero (0) line, the page count in the 'other' column is an indication of the number of buffer cache pages that are currently unused since besides unused pages the number of pages that actually fall under the 'other' heading is tiny. A persistent high number here can indicate that you may be able to reduce the number of BUFFERS without affecting performance. However, be sure to check during peak loads to be certain. 2) The summary at the bottom. In a healthy OLTP/DSS environment there is normally a ratio of about 60-80% data pages, 15-35% index (BTree) pages and a small 'other' (excluding any excess 'other' noted above). Btree is normally about 1/3 of the Data value. Obviously in a DW environment with far fewer indexes this ratio will not hold. Note that if you are running an early 7.3 or 9.2 release and the Btree value is over 60% you may be running into an old buffer aging bug. 3) Each partnum line. You can use this information to determine what tables and or indexes are being heavily hit and may benefit from fragmentation over several dbspaces to spread the load and take advantage of parallel scans. Also for smaller tables - noticing a lookup table whose page count flutuates from most of the table's pages to very few many times a day may identify a candidate table to be marked RESIDENT. Art S. Kagel > How to use onstat -P(not -p) to tell informix server's performance question:? > > > -- > Posted via http://dbforums.com

Thanks,You are so kind -- Posted via http://dbforums.com