判断oracle index 何时需要重建

oracle 索引何时需要重建

1.analyze index PUB_USER_FUNC_RESOURCE_INDEX3 validate structure;

2. 查询索引碎片：

select name,

del_lf_rows,

lf_rows,

round((del_lf_rows/(lf_rows+0.0000000001))*100) frag_pct

from index_stats

一般如果该索引的frag_pct>20%，那么就需要rebuild index

3.alter index PUB_USER_FUNC_RESOURCE_INDEX3 rebuild online;

--根据上面原理创建存储过程

CREATE OR REPLACE PROCEDURE rebuild_index IS

--收集索引的信息，决定是否需要重建

--analyze index PUB_USER_FUNC_RESOURCE_INDEX3 validate structure;

--select height,blocks,del_lf_rows,lf_rows, round(del_lf_rows/lf_rows*100) from index_stats;

--alter index PUB_USER_FUNC_RESOURCE_INDEX3 rebuild online;

CURSOR my_cursor IS SELECT OWNER,INDEX_NAME FROM dba_indexes WHERE owner IN ('NEW_JK');

v_indexname VARCHAR2(30);

v_owner VARCHAR2(30);

v_rate NUMBER(10);

v_name VARCHAR2(30);

v_sql VARCHAR2(100);

BEGIN

FOR i IN my_cursor LOOP

v_indexname:=i.index_name;

v_owner:=i.owner;

-- dbms_output.put_line('index_name is '||v_indexname);

v_sql:= 'ANALYZE INDEX '||v_owner ||'.'|| v_indexname ||' VALIDATE STRUCTURE';

dbms_output.put_line('analyze is '||v_sql);

EXECUTE IMMEDIATE v_sql;

BEGIN

SELECT NAME,round((del_lf_rows/(lf_rows+0.0000000001))*100) INTO v_name, v_rate FROM index_stats;

EXCEPTION

when NO_DATA_FOUND then

dbms_output.put_line('no data found');

goto end_loop;

END;

IF (v_rate > 20 ) THEN

dbms_output.put_line('index_name is '||v_owner||'.'||v_name || ' rate is '|| v_rate);

dbms_output.put_line('************begin rebuild online*****************');

dbms_output.put_line('ALTER INDEX '||v_owner||'.'||v_name ||' REBUILD ONLINE');

EXECUTE IMMEDIATE('ALTER INDEX '||v_owner||'.'||v_name ||' REBUILD ONLINE');

dbms_output.put_line('**************end rebuild online***************');

--EXIT;

END IF;

<<end_loop>>

null;

END LOOP;

END;

--执行存储过程

[oracle@server8 user_stat]$ cat index_rebuild.sh

#!/bin/bash

ORACLE_SID=ghsjdb

ORACLE_BASE=/home/u01/app/oracle

ORACLE_HOME=$ORACLE_BASE/product/11.2.0/db_1

export ORACLE_SID ORACLE_BASE ORACLE_HOME TARGET_SID

PATH=$PATH:$ORACLE_HOME/bin:/usr/local/bin

export PATH

NLS_LANG=AMERICAN_AMERICA.ZHS16GBK

export NLS_LANG

sqlplus / as sysdba <<EOF

exec ghsj_xm.user_stat;

exit

EOF

--设置定时服务

0 2 * * * /home/oracle/user_stat/index_rebuild.sh > /home/oracle/user_stat/index_rebuild.log

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