Scripts:重建索引的脚本(看懂脚本再用)rebuild_indx.sql

REM =============================================================

REM

REM                         rebuild_indx.sql

REM

REM  Copyright (c) Oracle Software, 1998 - 2000

REM

REM  Author  : Jurgen Schelfhout

REM

REM  The sample program in this article is provided for educational

REM  purposes only and is NOT supported by Oracle Support Services.

REM  It has been tested internally, however, and works as documented.

REM  We do not guarantee that it will work for you, so be sure to test

REM  it in your environment before relying on it.

REM

REM  This script will analyze all the indexes for a given schema

REM  or for a subset of schema's. After this the dynamic view

REM  index_stats is consulted to see if an index is a good

REM  candidate for a rebuild or for a bitmap index.

REM

REM  Database Version : 7.3.X and above.

REM

REM  NOTE:  If running this on 10g, you must exclude the

REM  objects in the Recycle Bin

REM        cursor c_indx is

REM          select owner, table_name, index_name

REM            from dba_indexes

REM           where owner like upper('&schema')

REM             and table_name not like 'BIN$%'

REM             and owner not in ('SYS','SYSTEM');

REM

REM  Additional References for Recycle Bin functionality:

REM  Note.265254.1 Flashback Table feature in Oracle Database 10g

REM  Note.265253.1 10g Recyclebin Features And How To Disable it(_recyclebin)

REM

REM =============================================================

 

prompt

ACCEPT spoolfile CHAR prompt 'Output-file : ';

ACCEPT schema CHAR prompt 'Schema name (% allowed) : ';

prompt

prompt

prompt Rebuild the index when :

prompt   - deleted entries represent 20% or more of the current entries

prompt   - the index depth is more then 4 levels.

prompt Possible candidate for bitmap index :

prompt   - when distinctiveness is more than 99%

prompt

 

spool &spoolfile;

set serveroutput on;

set verify off;

set linesize 140;

declare

  c_name        INTEGER;

  ignore        INTEGER;

  height        index_stats.height%TYPE := 0;

  lf_rows       index_stats.lf_rows%TYPE := 0;

  del_lf_rows   index_stats.del_lf_rows%TYPE := 0;

  distinct_keys index_stats.distinct_keys%TYPE := 0;

  cursor c_indx is

    select owner, table_name, index_name

      from dba_indexes

     where owner like upper('&schema')

       and owner not in ('SYS', 'SYSTEM');

begin

  dbms_output.enable(1000000);

  dbms_output.put_line('Owner           Index Name                              % Deleted Entries Blevel Distinctiveness');

  dbms_output.put_line('--------------  ---------------------------------            ------------  -----           -----');

 

  c_name := DBMS_SQL.OPEN_CURSOR;

  for r_indx in c_indx loop

    DBMS_SQL.PARSE(c_name,

                   'analyze index ' || r_indx.owner || '.' ||

                   r_indx.index_name || ' validate structure',

                   DBMS_SQL.NATIVE);

    ignore := DBMS_SQL.EXECUTE(c_name);

 

    select HEIGHT,

           decode(LF_ROWS, 0, 1, LF_ROWS),

           DEL_LF_ROWS,

           decode(DISTINCT_KEYS, 0, 1, DISTINCT_KEYS)

      into height, lf_rows, del_lf_rows, distinct_keys

      from index_stats;

    /*

    - Index is considered as candidate for rebuild when :

    -   - when deleted entries represent 20% or more of the current entries

    -   - when the index depth is more then 4 levels.(height starts counting from 1 so > 5)

    - Index is (possible) candidate for a bitmap index when :

    -   - distinctiveness is more than 99%

    */

    if (height > 5) OR ((del_lf_rows / lf_rows) > 0.2) then

      dbms_output.put_line(rpad(r_indx.owner, 16, ' ') ||

                           rpad(r_indx.index_name, 40, ' ') ||

                           lpad(round((del_lf_rows / lf_rows) * 100, 3),

                                17,

                                ' ') || lpad(height - 1, 7, ' ') ||

                           lpad(round((lf_rows - distinct_keys) * 100 /

                                      lf_rows,

                                      3),

                                16,

                                ' '));

    end if;

 

  end loop;

  DBMS_SQL.CLOSE_CURSOR(c_name);

end;

/

spool off;

set verify on;