Oracle重建索引Shell脚本、SQL脚本分享

索引是提高数据库查询性能的有力武器。没有索引，就好比图书馆没有图书标签一样，找一本书自己想要的书比登天还难。然而索引在使用的过程中，尤其是在批量的DML的情形下会产生相应的碎片，以及B树高度会发生相应变化，因此可以对这些变化较大的索引进行重构以提高性能。N久以前Oracle建议我们定期重建那些高度为4，已删除的索引条目至少占有现有索引条目总数的20%的这些表上的索引。但Oracle现在强烈建议不要定期重建索引。具体可以参考文章：Oracle 重建索引的必要性。尽管如此重建索引还是有必要的，只是不建议定期。本文给出了重建索引的脚本供大家参考。

1、重建索引shell脚本

robin@SZDB:~/dba_scripts/custom/bin> more rebuild_unbalanced_indices.sh 
# +-------------------------------------------------------+
# +  Rebulid unblanced indices             |
# +  Author : Leshami                  | 
# +  Parameter : No                   |
# +-------------------------------------------------------+

#!/bin/bash 
# --------------------
# Define variable
# --------------------

if [ -f ~/.bash_profile ]; then
. ~/.bash_profile
fi

DT=`date +%Y%m%d`;       export DT
RETENTION=1
LOG_DIR=/tmp
LOG=${LOG_DIR}/rebuild_unbalanced_indices_${DT}.log
DBA=Leshami@12306.cn

# ------------------------------------
# Loop all instance in current server
# -------------------------------------
echo "Current date and time is : `/bin/date`">>${LOG}

for db in `ps -ef | grep pmon | grep -v grep |grep -v asm |awk '{print $8}'|cut -c 10-`
do
  echo "$db"
  export ORACLE_SID=$db
  echo "Current DB is $db" >>${LOG}
  echo "===============================================">>${LOG}
  $ORACLE_HOME/bin/sqlplus -S /nolog @/users/robin/dba_scripts/custom/sql/rebuild_unbalanced_indices.sql>>${LOG}
done;

echo "End of rebuilding index for all instance at : `/bin/date`">>${LOG}
# -------------------------------------
# Check log file 
# -------------------------------------
status=`grep "ORA-" ${LOG}`
if [ -z $status ];then
  mail -s "Succeeded rebuilding indices on `hostname` !!!" ${DBA} <${LOG}
else
  mail -s "Failed rebuilding indices on `hostname` !!!" ${DBA} <${LOG}
fi

# ------------------------------------------------
# Removing files older than $RETENTION parameter 
# ------------------------------------------------

find ${LOG_DIR} -name "rebuild_unb*" -mtime +$RETENTION -exec rm {} \;

exit

2、重建索引调用的SQL脚本

robin@SZDB:~/dba_scripts/custom/sql> more rebuild_unbalanced_indices.sql 
conn / as sysdba
set serveroutput on;
DECLARE
  resource_busy        EXCEPTION;
  PRAGMA EXCEPTION_INIT (resource_busy, -54);
  c_max_trial    CONSTANT PLS_INTEGER := 10;
  c_trial_interval  CONSTANT PLS_INTEGER := 1;
  pmaxheight     CONSTANT INTEGER := 3;
  pmaxleafsdeleted  CONSTANT INTEGER := 20;

  CURSOR csrindexstats
  IS
   SELECT NAME,
       height,
       lf_rows AS leafrows,
       del_lf_rows AS leafrowsdeleted
    FROM index_stats;

  vindexstats         csrindexstats%ROWTYPE;

  CURSOR csrglobalindexes
  IS
   SELECT owner,index_name, tablespace_name
    FROM dba_indexes
    WHERE partitioned = 'NO'
    AND owner IN ('GX_ADMIN');

  CURSOR csrlocalindexes
  IS
   SELECT index_owner,index_name, partition_name, tablespace_name
    FROM dba_ind_partitions
    WHERE status = 'USABLE'
    AND index_owner IN ('GX_ADMIN');

  trial            PLS_INTEGER;
  vcount           INTEGER := 0;
BEGIN
  trial := 0;

  /* Global indexes */
  FOR vindexrec IN csrglobalindexes
  LOOP
   EXECUTE IMMEDIATE
     'analyze index ' || vindexrec.owner ||'.'|| vindexrec.index_name || ' validate structure';

   OPEN csrindexstats;

   FETCH csrindexstats INTO vindexstats;

   IF csrindexstats%FOUND
   THEN
     IF  (vindexstats.height > pmaxheight)
      OR (  vindexstats.leafrows > 0
        AND vindexstats.leafrowsdeleted > 0
        AND (vindexstats.leafrowsdeleted * 100 / vindexstats.leafrows) >
            pmaxleafsdeleted)
     THEN
      vcount := vcount + 1;
      DBMS_OUTPUT.PUT_LINE (
        'Rebuilding index ' || vindexrec.owner ||'.'|| vindexrec.index_name || '...');

      <<alter_index>>
      BEGIN
        EXECUTE IMMEDIATE
           'alter index '
         || vindexrec.owner ||'.'
         || vindexrec.index_name
         || ' rebuild'
         || ' parallel nologging compute statistics'
         || ' tablespace '
         || vindexrec.tablespace_name;
      EXCEPTION
        WHEN resource_busy OR TIMEOUT_ON_RESOURCE
        THEN
         DBMS_OUTPUT.PUT_LINE (
           'alter index - busy and wait for 1 sec');
         DBMS_LOCK.sleep (c_trial_interval);

         IF trial <= c_max_trial
         THEN
           GOTO alter_index;
         ELSE
           DBMS_OUTPUT.PUT_LINE (
              'alter index busy and waited - quit after '
            || TO_CHAR (c_max_trial)
            || ' trials');
           RAISE;
         END IF;
        WHEN OTHERS
        THEN
         DBMS_OUTPUT.PUT_LINE ('alter index err ' || SQLERRM);
         RAISE;
      END;
     END IF;
   END IF;

   CLOSE csrindexstats;
  END LOOP;

  DBMS_OUTPUT.PUT_LINE ('Global indices rebuilt: ' || TO_CHAR (vcount));
  vcount := 0;
  trial := 0;

  /* Local indexes */
  FOR vindexrec IN csrlocalindexes
  LOOP
   EXECUTE IMMEDIATE
      'analyze index '
     || vindexrec.index_owner||'.'
     || vindexrec.index_name
     || ' partition ('
     || vindexrec.partition_name
     || ') validate structure';

   OPEN csrindexstats;

   FETCH csrindexstats INTO vindexstats;

   IF csrindexstats%FOUND
   THEN
     IF  (vindexstats.height > pmaxheight)
      OR (  vindexstats.leafrows > 0
        AND vindexstats.leafrowsdeleted > 0
        AND (vindexstats.leafrowsdeleted * 100 / vindexstats.leafrows) >
            pmaxleafsdeleted)
     THEN
      vcount := vcount + 1;
      DBMS_OUTPUT.PUT_LINE (
        'Rebuilding index ' || vindexrec.index_owner||'.'|| vindexrec.index_name || '...');

      <<alter_partitioned_index>>
      BEGIN
        EXECUTE IMMEDIATE
           'alter index '
         || vindexrec.index_owner||'.'
         || vindexrec.index_name
         || ' rebuild'
         || ' partition '
         || vindexrec.partition_name
         || ' parallel nologging compute statistics'
         || ' tablespace '
         || vindexrec.tablespace_name;
      EXCEPTION
        WHEN resource_busy OR TIMEOUT_ON_RESOURCE
        THEN
         DBMS_OUTPUT.PUT_LINE (
           'alter partitioned index - busy and wait for 1 sec');
         DBMS_LOCK.sleep (c_trial_interval);

         IF trial <= c_max_trial
         THEN
           GOTO alter_partitioned_index;
         ELSE
           DBMS_OUTPUT.PUT_LINE (
              'alter partitioned index busy and waited - quit after '
            || TO_CHAR (c_max_trial)
            || ' trials');
           RAISE;
         END IF;
        WHEN OTHERS
        THEN
         DBMS_OUTPUT.PUT_LINE (
           'alter partitioned index err ' || SQLERRM);
         RAISE;
      END;
     END IF;
   END IF;

   CLOSE csrindexstats;
  END LOOP;

  DBMS_OUTPUT.PUT_LINE ('Local indices rebuilt: ' || TO_CHAR (vcount));
END;
/
exit;

3、输入日志样本

Current date and time is : Sun Apr 20 02:00:02 HKT 2014 
Current DB is SYBO2 ===============================================
Rebuilding index GX_ADMIN.SYN_OUT_DATA_TBL_PK...
Rebuilding index GX_ADMIN.IDX_TDBK_SPLNK_PARENT_REF...
Rebuilding index GX_ADMIN.IDX_TDBK_SPLNK_CHILD_REF...
Rebuilding index GX_ADMIN.PK_TRADE_BROKER_TBL...
Rebuilding index GX_ADMIN.IDX_TDBK_INPUT_DATE...
  ................

4、后记

a、如果同一台服务器上有多个实例，且每个实例有相同的schema，此脚本会轮巡所有实例并根据analyze结果来rebuild。
a、大家应根据需要作相应调整，如脚本的路径信息等。
b、需要修改相应的schema name。
d、可根据系统环境调整相应的并行度。