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  • [bbk5361] 第86集 第11章 数据库诊断 02

    数据库恢复专家,在进行修复的时候,有2个项选,其中之一是无损修复,另外一种是有损修复,可供DBA选择.

    执行ADVISE FAILURE与REPAIR FAILURE命令,必须是在同一个SESSION当中.修复工作,是无法并发操作的.

    使用数据库恢复专家,有两种途径:OEM方式及Manual方式,接下来介绍一下Manual方式

    Listing Data Failures

    The RMAN LIST FAILURE command lists previously executed failure assessment.

    • Including newly diagnosed failures
    • Removing closed failures(by default)

    Syntax:

    LIST FAILURE
    
    [ ALL | CRITICAL | HIGH | LOW | CLOSED | failnum[,failnum,...]] 
    
    [ EXCLUDE FAILURE failnum[,failnum,...]]
    
    [DETAIL]

    Advising on Repair

    The RMAN ADVISE FAILURE command:

    • Displays a summary of input failure list
    • Includes a warning,if new failures appeared in ADR
    • Displays a manula checklist
    • Lists a single recommended repair option
    • Generates a repair script(for automatic or manual repair)

     

    Executing Repairs

    The RMAN REPAIR FAILURE command:

    • Follows the ADVISE FAILURE command
    • Repairs the specified failure
    • Closes the repaired failure

    Syntax:

    REPAIR FAILURE
    
    [USING ADVISE OPTION integer]
    
    [ {{NOPROMPT | PREVIEW}}... ] 

    Classifying(and Closing) Failures

    The RMAN CHANGE FAILURE command:

    • Changes the failure priority(except for CRITICAL)(CHANGE FAILURE命令,可以将HIGH级别的故障,修改成LOW级别的故障.但是不可以将CRITICAL级别的故障,修改成HIGH级别的故障.)
    • Closes one or more failures

    Example:

    Data Recovery Advisor Views

    Querying V$ views:(查看动态性能视图,查看数据库恢复专家相关的动态性能视图)

    • V$IR_FAILURE:List of all failures,including closed ones(result of the LIST FAILURE command)
    • V$IR_MANULA_CHECKLIST:List of manual advice(result of the ADVISE FAILURE command)
    • V$IR_REPAIR:List of repairs(result of the ADVISE FAILURE command)
    • V$IR_FAILURE_SET:Cross-reference of failure and advice identifiers

    Best Practice:Proactive Checks

    DBA具备前瞻性的眼光,提前进行健康检查(主动防御、主动检查)

    Invoking proactive health check of the database and its components:

    • Health Monitor or RMAN VALIDATE DATABAES command
    • Checking for logical and physical corruption
    • Finding logged in the ADR 
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  • 原文地址:https://www.cnblogs.com/arcer/p/3118334.html
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