discardmax--numberofdiscards toallow(Default all)skip--numberoflogical records toskip(Default0)load--numberoflogical records toload(Default all)errors--numberoferrors toallow(Default50)rows--numberofrowsinconventional path bind array or between direct path datasaves(Default:Conventional path250,Direct...
second row to be fetched is now the first row and is also assigned a ROWNUM of 1 and makes the condition false. All rows subsequently fail to satisfy the condition, so no rows are returned. 因为rownum是根据查询的结果集来对记录进行编号,所以当你查询rownum大于2的记录时会得到一个空的结果集。
1、账户锁定指定cfmaster这个用户最多只能尝试3次登录,锁定时间为2天 SQL>create profile lock_account limit failed_login_attempts 3 >password_lock_time 2; SQL>alter user cfmaster profile lock_account; 2、账户解锁 SQL>alter user cfmaster account unlock; 3、终止口令给用户xiaoming创建一个profile文件,...
帮朋友优化一条很简单的窗口函数 ROW_NUMBER() OVER() , Oracle 迁移 KingBase 项目。 原始SQL和执行计划 STUDENT_BAK 表我模拟的数据,3千万行数据。 sql SELECTSTU_ID, STU_NAME, STU_SEX, STU_AGE, STU_DATE, STU_CLASSID, STU_SALFROM(SELECTSB.*,ROW_NUMBER()OVER(PARTITIONBYSB.STU_CLASSID,SB.S...
chain_cnt :Number of rows in the table that are chained from one data block to another or that have migrated to a new block, requiring a link to preserve the old rowid. This column is updated only after you analyze the table.
NUMBER_OF_FILES FROM v$flash_recovery_area_usage b, v$recovery_file_dest c WHERE c.SPACE_LIMIT <> 0 UNION ALL SELECT bb.FILENAME || '---' || bb.STATUS, (c.SPACE_LIMIT / 1024 / 1024) SPACE_LIMIT_m, (bb.BYTES / 1024 / 1024) space_used, round(bb.BYTES * 100 / c.SPACE_...
Oracle-SQL长度限制 最近遇见一个ORA-01795: maximum number of expressions in a list is 1000 错误,才知道In-list有1000个元素的限制;可以使用array bind或者temporary table解决,而且还能绑定变量。[Limit and conversion very long IN list : WHERE x IN ( ,,, ...) ] 54ne.com...
AVG_ROW_LEN还是比较准的,比如个人实验情况一表6个字段,一个number,其他5个都是char(100)但是实际数据都是’1111111’7位,AVG_ROW_LEN显示依然为513 SELECT TABLE_NAME,(BLOCKS*8192/1024/1024)"理论大小M",(NUM_ROWS*AVG_ROW_LEN/1024/1024/0.9)"实际大小M",round((NUM_ROWS*AVG_ROW_LEN/1024/1024/0....
oracle sql 高级编程学习笔记(二十) 一、Model 子句剖析: 通过model return updated rows 或者model来声明这个语句 使用model子句。一个model子句有三组列,分区列,唯独列, 以及度量值列。 分区列类似于电子表格excel中的一张工作表, 维度列类似于行标签(A,B,C……)和列标签(1,2,3……)...
Exec(`CREATE TABLE TABLE1( ID number(10), NAME varchar2(50), DAT DATE )`) // check for errorsquery example: rows, err := conn.Query("SELECT ID, NAME, DAT FROM TABLE1") // check for errors defer rows.Close() var ( id int64 name sql.NullString date sql.NullTime ) for rows....