Shulou(Shulou.com)06/01 Report--

First of all, understand the following two pictures

Description:

1. Generally speaking, the Oracle server generally contains an instance + a database.

two。 Instances generally refer to memory and processes, which are dynamic; databases refer to files stored in the operating system, which are static.

Example

1. Process: ps-ef | grep ora_ | grep-v grep to check which processes are available.

2. Memory:

SGA:

An instance has only one SGA, all session shares, which are released as instance shuts down

Components:

Shared pool:

The memory area for parsing, compiling and executing SQL and PL/SQL programs

The size of the shared pool directly affects the performance of the database.

It is composed of library cache (library cache), data dictionary cache (data dictionary cache), result cache (resultcache), etc.

Database buffer cache

Redo log buffer

Large pool / java pool / streams pool

PGA

Memory management: (distinguish parameters between 10g and 11g)

Database

1. Data file v$datafile

two。 Control file v$controlfile

3. Log file v$logfile

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