Re: db_block_lru_extended_statistics

On Thu, 24 Sep 1998 13:39:19 GMT, Michael L. Mason <mmason1_at_osf1.gmu.edu> wrote:
>Help!
>
>In an attempt to tune our database, I have enabled the above parameter
>and have looked at the x$kcbrbh table. According to my Database Tuning
>instructor the 'count' column on said table should have decreasing
>values. When I looked at the table, I saw values in the 'count' column
>vary greatly. In buffers 1-50 there were some buffers with anywhere
>from 1-30 'hits'. However, on buffer number 205 we had 1151 hits. Why
>would there be so many hits on this particular buffer. I was thinking
>that it might have something to do with the process that scans for free
>buffers. Because some buffers stay populated longer than others, these
>buffers may be skipped when searching for clean ones. Does this sound
>right?
>
>Thanks!
>Mike

I think you probably have the reasons correct. In practice the numbers do not fall off smoothly, even the examples in the various Oracle press manuals do not. Just keep adding to the bufer pool until you reach an obvious fall off.

Keith Matthews
Developer/DBA Received on Thu Sep 24 1998 - 14:38:16 CDT