Oracle dynamic performance view v $ SGA Study Notes

In the dynamic performance view of Oracle, V $ SGA has no other views.

The structure is as follows:

SQL> DESC v $ SGA
Is the name empty? Type
-------------------------------------------------------------------------------------------------
Name varchar2 (20)
Value number

There are only two fields, type name and Value

View data:

SQL> select * from V $ SGA;

NAME value
------------------------------
Fixed size 453252
Variable Size 46137344
Database buffers 37748736
Redo Buffers' 667648

This view has four records, which are described as follows:

First: fixed size

Similar to the SGA boot module of Oracle, this module stores the component information of SGA and guides the creation of SGA. On a specific platform, the size varies. However, the size of the platform is the same.

Second: Variable Size

It mainly includes the following parts:

Shared_pool, java_pool, large_pool, and hash table for memory management.

Third, database Buffers

It refers to the data buffer cache in SGA. Oracle 8i/Oracle 9i is different.

Oracle 8i consists of three parts: Default pool, buffer_pool_keep, and buffer_pool_recycle.

Oracle 9i consists of db_cache_size, db_keep_buffer_size, db_buffer_recycle_size, and db_nk_cache_size.

Fourth. Redo Buffers

The size of the redo log buffer.