Decreasing page read statistic

Help..... Does anyone have any idea how the number of page reads can decrease over time? You can see that the first number is 37,567,198 and two hours later the number is 33,234,182. dskreads and bufreads are increasing. I know that I need to add more buffers since my cache rate is so low and I am running with 400,000 now. But I wouldn't think that that has any effect on the number of pages. tnx....... Informix Dynamic Server Version 7.30.UC3XD -- On-Line -- Up 9 days 16:12:14 -- 1865072 Kbytes Profile dskreads pagreads bufreads %cached dskwrits pagwrits bufwrits %cached 113965564 37567198 613697949 81.43 361345 2065617 2257957 84.00 isamtot open start read write rewrite delete commit rollbk 139761888 3070730 5778310 116717741 625501 30885 1827 36244 108 gp_read gp_write gp_rewrt gp_del gp_alloc gp_free gp_curs 0 0 0 0 0 0 0 ovlock ovuserthread ovbuff usercpu syscpu numckpts flushes 0 0 0 52398.49 4530.19 121 242 bufwaits lokwaits lockreqs deadlks dltouts ckpwaits compress seqscans 1911233 0 904998215 0 0 147 8837 94638 ixda-RA idx-RA da-RA RA-pgsused lchwaits 2741427 303197 93159846 96200359 33861 nazareth% !! onstat -p Informix Dynamic Server Version 7.30.UC3XD -- On-Line -- Up 9 days 18:23:52 -- 1865072 Kbytes Profile dskreads pagreads bufreads %cached dskwrits pagwrits bufwrits %cached 129767490 33234182 739778496 82.46 553719 4369801 2859226 80.63 isamtot open start read write rewrite delete commit rollbk 183013620 3872363 7394930 153843764 727368 35022 1830 42560 108 gp_read gp_write gp_rewrt gp_del gp_alloc gp_free gp_curs 0 0 0 0 0 0 0 ovlock ovuserthread ovbuff usercpu syscpu numckpts flushes 0 0 0 60226.40 5266.68 130 260 bufwaits lokwaits lockreqs deadlks dltouts ckpwaits compress seqscans 2243715 0 1066935264 0 0 158 9323 114065 ixda-RA idx-RA da-RA RA-pgsused lchwaits 4259738 364243 105025639 109645553 36078

This is probably related to a bug. Its been seen on 7.30uc3 running on Solaris 2.5(at least) . If you look into sysmaster tables that report Pages read/written statistics (e.g syschkio), you could find some negative values. It appears that when values exceed 1048576, they become negative [stored in 20 bits]. Tech. support could elaborate. Rudy Doug McAllister wrote: > Help..... > > Does anyone have any idea how the number of page reads can decrease over > time? You can see that the first number is 37,567,198 and two hours > later the number is 33,234,182. dskreads and bufreads are increasing. I > know that I need to add more buffers since my cache rate is so low and I > am running with 400,000 now. But I wouldn't think that that has any > effect on the number of pages. > > tnx.......

Thanks... Bug #123461 (on the syschktab table) looks like the culprit. Rudy Fernandes wrote: > This is probably related to a bug. Its been seen on 7.30uc3 running on > Solaris 2.5(at least) . If you look into sysmaster tables that report Pages > read/written statistics (e.g syschkio), you could find some negative > values. It appears that when values exceed 1048576, they become negative > [stored in 20 bits]. > > Tech. support could elaborate. > > Rudy > > Doug McAllister wrote: > > > Help..... > > > > Does anyone have any idea how the number of page reads can decrease over > > time? You can see that the first number is 37,567,198 and two hours > > later the number is 33,234,182. dskreads and bufreads are increasing. I > > know that I need to add more buffers since my cache rate is so low and I > > am running with 400,000 now. But I wouldn't think that that has any > > effect on the number of pages. > > > > tnx.......