Increased physical reads on a single datafile

Gurus ...

A single tablespace/datafile is showing a huge increase in phys reads since the end of March. The numbers are:

DATE PHYRDS READ_PCT PHYWRTS WRITE_PCT

Mar 22    3,863          0.21      651        0.23
Apr 28    5,985,597 76.84          757        0.12

All other datafiles show just minor variation. Most are at less than 1% for read and write pct, and the few that do have higher physical read or writes are the major players in the application, but still remain below 3 % for datafiles, and between 3 to 5% for the index files. I have checked and all the indexes are still in place and the schema has been analyzed nightly (compute) This tablespace holds 6 frequently used but smaller tables. No changes on the server except that the SA updated firmware. DB hit ratio has nosed dived from approx. 95% to 75%, but the problem appears to be confined to this tablespace. SGA settings have not been changed.

Any suggestions on what to investigate next would be appreciated!! Received on Fri Apr 28 2000 - 14:40:56 CDT