Performance problems with large table

I created one table with 500 columns and about 84600 records. The first column is of type DATE the remaining comlumns are of type NUMBER. Columns are added or deleted from the table using triggers when entries in other tables change.
The database was created with a block size of 8K under Windows NT 4.0 with Oracle Enterprise Server 8.0.3.
When performing queries response time is very poor! For example a "SELECT COUNT(*) ..." needs about 5 minutes to complete. At last I used the ANALYZE command with the LIST CHAINED ROWS option to determine chained or migrated rows and almost every second row is a chained row. So I copied the contents of the whole table to a new table to avoid chained rows - but with no success. What can we do to increase performance and decrease chained rows. Should we change initialization parameters (db_block_size, etc.)?

Please reply to my email address.

Thanxs in advance

Martin

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*  Ing. Martin Gamperl

*  MGS Messgeraetesteuerung - Softwareentwicklung

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