declare cursor [del_cursor] is select a.*, a.rowid row_id from [table_name] a order by a.rowid; begin for v_cusor in [del_cursor] loop if v_cusor.[time_stamp] < to_date('2014-01-01','yyyy-mm-dd') then delete from [table_name] where rowid = v_cusor.row_id; end if...
SpecifyWITH CHECK OPTIONto indicate that Oracle Database prohibits any changes to the table or view that would produce rows that are not included in the subquery. When used in the subquery of a DML statement, you can specify this clause in a subquery in the FROM clause but not in subquery...
B_S.ROW_WAIT_FILE#, B_S.ROW_WAIT_BLOCK#, B_S.ROW_WAIT_ROW#) ||''', NULL) BLOCKED_DATA_QUERYSQL FROMGV$LOCK A, GV$LOCK B, GV$SESSIONA_S, GV$SESSIONB_S, DBA_OBJECTS OBJ WHEREA.ID1 = B.ID1 ANDA.ID2 = B.ID2 ANDA.BLOCK > 0 --BLOCK THE OTHERSQL ANDB.REQUEST > 0...
1. CHAR类型数组变量 EXEC SQL for :delete_rows delete FROM table_name WHERE a= :a; 由于char对应于Oracle的char类型,因此若有空格,则此时char即使用memset初始化,但也会带有后面的空格,有可能造成delete时where a=:a由于空格不匹配无法删除,例如:a赋值为'a’,但数组长度是3,因此实际where条件是a='a ',...
...cascade; delete from dept_test where deptno = 1; 1 row deleted. 2.9K30 splice delete详解 let arr = [1, 2, 3, 4, 5]; //arr.splice(2,1);//从下标2开始删除当前元素 delete...arr[4];// // 注意点: 通过delete来删除数组中的元素, 数组的length属性不会发生变化 console.log(arr)...
而truncate操作在Oracle,MySQL都是一个极快的过程,在Oracle中不会直接抹去数据,数据还是依旧存在,在一定的条件下触发才会回收。 我们使用dbms_rowid来解析一下 SQL> select dbms_rowid.ROWID_RELATIVE_FNO(rowid) as file#,dbms_rowid.ROWID_BLOCK_NUMBER(rowid) as block#,dbms_rowid.ROWID_ROW_NUMBER(rowid) as...
假设我们要删除order_history上order_id<1999999的所有记录, 占到总行数的50%。由于order_history是非分区表,所以这里无法用Oracle的并行执行Parallel Execution来加速操作。 因此我们利用上述脚本来构造多条DML语句: SQL> @rowid_chunk Enter value for rowid_ranges: 24 ==>这里输入要构造的rowid分区个数 ...
In this post we'll start with a quick recap ofhow delete works. Then look at several alternatives you can use in Oracle Database to remove rows faster: Removing all the rows fast withtruncate Usingcreate-table-as-selectto wipe a large fraction of the data ...
EOF For Each fld In rs.Fields Debug.Print fld.Value, Next rs.MoveNext Debug.Print Loop rs.Close 'rs insert rs.Open "select * from my_ado", conn, adOpenDynamic, adLockOptimistic rs.AddNew rs!ID = 8 rs!Name = "Mandy" rs!txt = "Insert row" rs.Update rs.Close 'rs update rs.Open ...
All rows in Oracle have a rowid. This is a physical locator. That is, it states where on disk Oracle stores the row. This unique to each row. So you can use this value to identify and remove copies. To do this, replace min() with min(rowid) in the uncorrelated delete: ...