-
编辑 删除
decode
写了一个抓取造成等待事件的SQL,里面应用到DECODE.记录一下。[@more@]select /*+ ORDERED */ sql_text, hash_value, address from v$sqltext c, (select sql_hash_value, sql_address from (select DECODE(sql_hash_value, 0, prev_hash_value, sql_hash_value) sql_hash_value, DECODE(sql_hash_value, 0, prev_sql_addr, sql_address) sql_address from v$session --
-
编辑 删除
minus
集合操作minus，在sql中是经常用到的，这也是作为dba必须掌握的.下面是minus用法示例：[@more@]create table t (a number,b number,c number);create table t1 (a number,b number,c number);insert into t values(1,2,3);insert into t values(4,5,6);insert into t values(10,11,12);insert into t1 values(1,2,3);insert into t1 values(7,8,9);insert into t1 values(13,14,15);commit;select * from t;a b c1 2 34 5 610 11 12select * from t1;a b c1 2 37 8 913 14 15t minus t1select * from tminusselect * from t1;a b c4 5 610
