Cached Table

[Sofiane]

Hello,

Suppose that you cache a table T1 having :

NUM_ROWS : 150904
BLOCKS : 3140
EMPTY_BLOCKS : 25019
AVG_ROW_LEN : 76
INITIAL_EXTENT : 115343360
NEXT_EXTENT : 10485760

Extent : 1
DB_block : 4Ko


I would like to cache this table in the buffer cache, I would like to know the number of buffer blocks that will be occupied :

28160 (3140+25019+1) buffer blocks (110 Mo)
or
only : 3140 (12,3 Mo)

Thanks in advance

Sofiane

[sln81]

It might require 3140 blocks as the server process reads all blocks below high water mark. Better you can partition your buffer cache itself if you are running on 8i, to include a keep section and cache such table's blocks.

[Sofiane]

Hi,

Thanks for the reply... We are currently using Oracle 7.3.4 and so we can't define keep and recycle area.

A second question, how can we monitor the buffer cache (see the table currently cached, the free space ... I tried to use x$bh but I find the information providedare not detailed...)

Thanks a lot

Sofiane

[hrishy]

hi sofianne

perhaphs this qursy would help you to find the tables that are currently being cached .

select name,type
2> from v$db_object_cache
3> where type='TABLE';

however i am not sure what are your other requirements.

hope thsi helps