提高Oracle的查询统计速度方法简介

核心提示： SELECT SEGMENT_NAME FROM DBA_ROLLBACK_SEGS WHERE INITIAL_EXTENT < 512000 ANDUPPPER(OWNER) = 'PUBLIC';SELECT UPPER(STATUS) FROM DBA_ROL

SELECT SEGMENT_NAME FROM DBA_ROLLBACK_SEGS WHERE INITIAL_EXTENT < 512000 AND
UPPPER(OWNER) = 'PUBLIC';
SELECT UPPER(STATUS) FROM DBA_ROLLBACK_SEGS WHERE UPPER(SEGMENT_NAME) = ''
ALTER ROLLBACK SEGMENT RB1 OFFLINE;
ALTER ROLLBACK SEGMENT RB2 OFFLINE;
ALTER ROLLBACK SEGMENT RB3 OFFLINE;
ALTER ROLLBACK SEGMENT RB4 OFFLINE;
ALTER ROLLBACK SEGMENT RB5 OFFLINE;
DROP ROLLBACK SEGMENT RB1;
DROP ROLLBACK SEGMENT RB2;
DROP ROLLBACK SEGMENT RB3;
DROP ROLLBACK SEGMENT RB4;
DROP ROLLBACK SEGMENT RB5;
CREATE PUBLIC ROLLBACK SEGMENT RB1 TABLESPACE ROLLBACK_DATA
　 STORAGE (INITIAL 512000 NEXT 512000 MAXEXTENTS 121);
CREATE PUBLIC ROLLBACK SEGMENT RB2 TABLESPACE ROLLBACK_DATA
　 STORAGE (INITIAL 512000 NEXT 512000 MAXEXTENTS 121);
CREATE PUBLIC ROLLBACK SEGMENT RB3 TABLESPACE ROLLBACK_DATA
　 STORAGE (INITIAL 512000 NEXT 512000 MAXEXTENTS 121);
CREATE PUBLIC ROLLBACK SEGMENT RB4 TABLESPACE ROLLBACK_DATA
　 STORAGE (INITIAL 512000 NEXT 512000 MAXEXTENTS 121);
CREATE PUBLIC ROLLBACK SEGMENT RB5 TABLESPACE ROLLBACK_DATA
　 STORAGE (INITIAL 512000 NEXT 512000 MAXEXTENTS 121);
ALTER ROLLBACK SEGMENT RB1 ONLINE;
ALTER ROLLBACK SEGMENT RB2 ONLINE;
ALTER ROLLBACK SEGMENT RB3 ONLINE;
ALTER ROLLBACK SEGMENT RB4 ONLINE;
ALTER ROLLBACK SEGMENT RB5 ONLINE;
COMMIT;

将数据量大的库存表等放在一簇内的SQL语句如下：