1.76 DB_BLOCK_SIZE
DB_BLOCK_SIZE
specifies (in bytes) the size of Oracle database blocks.
Property | Description |
---|---|
Parameter type |
Integer |
Default value |
|
Modifiable |
No |
Modifiable in a PDB |
No |
Range of values |
|
Basic |
Yes |
Oracle RAC |
You must set this parameter for every instance, and multiple instances must have the same value. |
Note:
Set this parameter at the time of database creation. Do not alter it afterward.
Typical values for DB_BLOCK_SIZE
are 4096
and 8192
. The value of this parameter must be a multiple of the physical block size at the device level.
The value for DB_BLOCK_SIZE
in effect at the time you create the database determines the size of the blocks. The value must remain set to its initial value.
For Oracle Real Application Clusters (Oracle RAC), this parameter affects the maximum value of the FREELISTS
storage parameter for tables and indexes. Oracle uses one database block for each freelist group. Decision support system (DSS) and data warehouse database environments tend to benefit from larger block size values.
Note:
64-bit operating systems support a maximum DB_BLOCK_SIZE
value of 32768
See Also:
-
Oracle Database Administrator’s Guide for information on setting this parameter
-
Oracle Database SQL Language Reference for information on freelist groups