How to analyze ORACLE faults

How to analyze ORACLE faults
When system query is interrupted or slowed down, system hangs, system is down, etc., the analysis process is as follows:
(1) Analyze the alert_.log file
You can analyze the fault from this file Occurrence time, phenomenon log, trace file (*.trc). For example, when a large transaction operation causes the rollback segment or temporary segment to overflow and the system is temporarily interrupted or slowed down, the table space overflow will be recorded in the log file; when a fault is caused by a certain SQL statement, the trace file will record the statement content.
(2) Check init.ora
This file is the ORACLE startup file. Any parameter configuration error will cause ORACLE to fail to start. Any unreasonable parameter configuration may cause system failure. The file content is as follows:
·gc_rollback_segments = 40//Number of rollback segments (default is 18) Only ORACLE7.3.x has this parameter
·rollback_segments= (r01,r02,r03,r04)//Rollback segments used by the system
·Db_block_buffer=60000     / /Data block buffer: 120M Unit: block (2048Bytes)
·Share_pool_size=30000000//Shared pool: 30M Unit: byte
·Processes=200//Number of processes
·Log_buffer=163840//Log buffer: 160M Unit: byte (note: if it is an integer multiple of block 2048)
·compatible = 7.3.0.0 //Must be version 7.3 or above, ORACLE8 does not require this parameter
Description:
Db_block_buffer: It is the main parameter of SGA, the buffer where data is stored.
Share_pool_size (shared pool): stores all ORACLE scripts, such as stored procedures, etc., does not need to be too large.
Log_buffer: The log buffer during transaction operations. If it is too small, a simple update operation cannot be submitted, causing the system to pause briefly.
rollback_segments: Specify the rollback segments used by ORACLE. The default is four. This value must be modified after creating the rollback segment and restarting ORACLE for the created rollback segment to take effect.
compatible: Compatibility version, the default is 7.1.0.0, some SQL statements require that the version must be 7.3.0.0 or above.
Note:
The above parameter configuration is only a reference and does not represent everything. In actual applications, it should be flexibly configured according to different machine configurations and usage services.

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