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Oracle Tips by Burleson |
Investigate Your Oracle
Database
After reading all of the reading assignments
and performing the exercises for this tutorial, you will need to
verify the size of your Oracle database buffers inside the SGA.
The goal of this assignment is to use the
“show sga” command, and see the total RAM region size for your Oracle
database. Then you will use the “show parameter” command to display
all of the parameters that make up the SGA.
For example, your “show sga” command may look
like this:
SQL> show
sga
Total System
Global Area 143421172 bytes
Fixed Size 282356 bytes
Variable Size 92274688 bytes
Database Buffers 50331648 bytes
Redo Buffers 532480 bytes
Here we see that the total SGA size is 1.43
gigabytes and the Oracle database buffers are 50 megabytes.
Your challenge is to display all components
that make up the data buffer size and verify that the show sga command
is correct.
ANSWER
We know that the Oracle database buffer size
is determined by the sum of the values of cache_size parameters (db_block_buffers
in Oracle8i). We can display db_cache parameters as follows:
SQL> show
parameter cache_size
NAME TYPE VALUE
------------------------------------ ----------- ----------------
db_16k_cache_size big integer 16777216
db_2k_cache_size big integer 0
db_32k_cache_size big integer 0
db_4k_cache_size big integer 0
db_8k_cache_size big integer 0
db_cache_size big integer 33554432
db_keep_cache_size big integer 0
db_recycle_cache_size big integer 0
Here we see that the db_cache_size is 33 meg
and the db_16k_cache_size is 17 meg, for a total of 50 meg.
For more details, see the "Easy
Oracle Series" a set of books especially designed by Oracle
experts to get you started fast with Oracle database technology.
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