TRANSACTIONAL TEXT INDEX全文索引可能消耗大量PGA内存

在版本10.2中存在<BUG 6624968 - A QUERY AGAINST A TRANSACTIONAL TEXT INDEX CONSUMES HUGE PGA MEMORY>对于文本索引的查询可能引发PGA内存过量消耗， 如以下演示：    

SQL> select * from v$version;

BANNER
----------------------------------------------------------------
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - 64bi
PL/SQL Release 10.2.0.1.0 - Production
CORE    10.2.0.1.0      Production
TNS for Linux: Version 10.2.0.1.0 - Production
NLSRTL Version 10.2.0.1.0 - Production
SQL> 
SQL> 
SQL>  CREATE TABLE TESTTAB (COL1 NUMBER, COL2 VARCHAR2(500),
  2   CONSTRAINT PK_COL1 PRIMARY KEY (COL1));

Table created.

SQL>  CREATE INDEX CTXI ON TESTTAB (COL2)
  2   INDEXTYPE IS CTXSYS.CONTEXT PARAMETERS('TRANSACTIONAL');

Index created.

 BEGIN
 FOR CNT IN 1..5000 LOOP
 INSERT INTO TESTTAB VALUES
 (CNT,'123456789 123456789 123456789 123456789 123456789 ');
 IF MOD(CNT,500)=0 THEN COMMIT;
 END IF;
 END LOOP;
 END;
 /

PL/SQL procedure successfully completed.

SQL> conn maclean/oracle
Connected.

 SELECT COL1 FROM TESTTAB WHERE CONTAINS(COL2,'%2') > 0;

SQL> col name for a30
SQL> set linesize 140 pagesize 1400
SQL>  select ss.sid, sn.name, ss.value
  2   from v$session se, v$sesstat ss,v$statname sn
  3   where ss.STATISTIC#=sn.STATISTIC# and se.SID=ss.SID
  4   and se.USERNAME='MACLEAN' and sn.name like '%pga%';

       SID NAME                                VALUE
---------- ------------------------------ ----------
       159 session pga memory              330403416
       159 session pga memory max          331976280

 BEGIN
 FOR CNT IN 1..50000 LOOP
 INSERT INTO TESTTAB VALUES
 (CNT,'123456789 123456789 123456789 123456789 123456789 ');
 IF MOD(CNT,500)=0 THEN COMMIT;
 END IF;
 END LOOP;
 END;
 /	   

SQL> set linesize 140 pagesize 1400 
SQL>  select ss.sid, sn.name, ss.value
  2   from v$session se, v$sesstat ss,v$statname sn
  3   where ss.STATISTIC#=sn.STATISTIC# and se.SID=ss.SID
  4   and se.USERNAME='MACLEAN' and sn.name like '%pga%';

       SID NAME                                                                  VALUE
---------- ---------------------------------------------------------------- ----------
       159 session pga memory                                                983993944
       159 session pga memory max                                            985108056

SQL> 
SQL> /

       SID NAME                                                                  VALUE
---------- ---------------------------------------------------------------- ----------
       159 session pga memory                                                991071832
       159 session pga memory max                                            992185944

SQL> /

       SID NAME                                                                  VALUE
---------- ---------------------------------------------------------------- ----------
       159 session pga memory                                                993693272
       159 session pga memory max                                            994807384

SQL> /

       SID NAME                                                                  VALUE
---------- ---------------------------------------------------------------- ----------
       159 session pga memory                                               1000771160
       159 session pga memory max                                           1001885272

SQL> /

       SID NAME                                                                  VALUE
---------- ---------------------------------------------------------------- ----------
       159 session pga memory                                               1127648856
       159 session pga memory max                                           1128762968

SQL> /

       SID NAME                                                                  VALUE
---------- ---------------------------------------------------------------- ----------
       159 session pga memory                                               1130008152
       159 session pga memory max                                           1131122264

SQL> /

       SID NAME                                                                  VALUE
---------- ---------------------------------------------------------------- ----------
       159 session pga memory                                               1131974232
       159 session pga memory max                                           1133088344

SQL> /

       SID NAME                                                                  VALUE
---------- ---------------------------------------------------------------- ----------
       159 session pga memory                                               1133678168
       159 session pga memory max                                           1134792280

SQL> /

       SID NAME                                                                  VALUE
---------- ---------------------------------------------------------------- ----------
       159 session pga memory                                               1197641304
       159 session pga memory max                                           1198755416

SQL> /

       SID NAME                                                                  VALUE
---------- ---------------------------------------------------------------- ----------
       159 session pga memory                                               1200262744
       159 session pga memory max                                           1201376856

SQL> /

       SID NAME                                                                  VALUE
---------- ---------------------------------------------------------------- ----------
       159 session pga memory                                               1695321688
       159 session pga memory max                                           1696435800

    该BUG已确认在版本10.2.0.4和11.1.0.7之前可以重复触发。 解决方法主要是达到最新的patchset