Oracle

Today found that the company Linux server under the root user can not switch to Oracle users through Su-oracle, so Baidu. The result is that the number of open files is too large, considering that the kill process is too risky, decide to modify the

SelectTo_char (Sysdate,'YYYY-MM-DD Hh24:mi:ss') fromDual--Show Current Time . - Geneva - - -: the: -SelectTrunc (Sysdate,' Year') fromDual--interception to year (first day of the year) . / 1 / 1SelectTrunc (Sysdate,'Q') fromDual--Intercept to

1. Use the| | "Join multiple fields and merge into one column2. Shielding repeated linesa pseudo-column in 3.Oracle is like a table column, but it is not stored in a tableRownum>3 because he couldn't find it for the first time, he couldn't find

I. Getting Started with SQL PlusSql*plus is one of the most commonly used tools, with strong features, mainly:1. Database maintenance, such as startup, shutdown, etc., which is generally operated on the server.2. Execute the SQL statement to execute/

Empty table settings are also requiredOwner can export empty tableExp Ss_sc_manager/[email protected] Owner=ss_sc_manager file=d:\2017048 backup. DMPImp ss_sc_manager/[email protected] file=d:\2017048 backup. DMP、、、、、、、、、、、、、、、、、、、、、 CREATE table

Summary Oracle's over-child functions can be sorted by the specified field grouping, sorting the result set for the same grouping field, where partition by is the grouping field, and order by specifies the sort field, which is an unexpected

Oracle BULK INSERT DataStudied: http://blog.csdn.net/chenleixing/article/details/45165761/Worship, quote the original:So is there any other way?? The answer is yes, perhaps familiar with the Oracle database may know from the Oracle9i version later,

As mentioned on the phone, OracleThe internal optimizer is based on a series of internalThe algorithm is based on statistical information on the table to generateThe line plan. For a particularly complex SQL languageOracle's optimizer has a chance

Oracle Output tree structuretree structure, root select Connect_by_root (cat.parentid) Root,cat.id,cat.parentid,cat.name,cat.code from V cat start with Cat.parentid in (37558) connect by prior cat.id= Cat.parentidTree structure, Primary subdirectory

Create or Replace procedureProc_insertuseramount (userid Number, Msgtype Number, Amountvalue Number, Financetype Number, Createuserid Number, MsgId nvarchar2, remark nvarchar2, Addtime date) isv_cnt Number; V_beforevalue Number; V_aftervalue Number;

1.Link CommandConnection command:Connsql>Conn system/manager; connect the system user with the password manager Disconnect command:discsql>Disc SystemChange Password command:passwordsql>Password System/manager;Then enter the old password before

Forwarded from, http://caowei3047.iteye.com/blog/438364Sometimes the data is dead, or no listening, do not have to restart the machine, restart the database service line, the following is the Linux boot step, did not execute under win, may also

It is too slow to update the data with a cursor, and after a series of queries in the same table is deleted, the insertions are likely to be overloaded, so it is important to process the data in batches, and here are some of the functional

SGA (System global Area), a share of the shared memory area that is shared by some of the associated processes of Oracle, is allocated in memory. such as Dbwn,pmon.The SGA is divided into the following components:1. Cache area2. Redo Log Buffers3.

--Grade ranking tabledrop table GraderecordCREATE TABLE Graderecord (Sno VARCHAR2 (10),Sname varchar2 (20),Dormitory VARCHAR2 (5),Grade int)Partition by range (grade) (Partition Bujige values less than (60),Partition Jige values less than

Method One:Sql> explain plan for select name from a A, where a.id=b.id; Sql> select * FROM table (Dbms_xplan. DISPLAY);Method Two:Sql> set autotrace on explain; Open execution plan sql> select name from a, b where a.id=b.id;When you are finished,

　　 when you use Plsql to connect to a database after startup starts the database ,ora-12170 error occurred:Make sure to check the status of the Oracle listener using the LSNRCTL status command before starting, shutting down, or restarting the Oracle

The index of the database if there are more frequent Delete operations, it can cause the index to produce a lot of fragmentation, so, at some point, all indexes need to be re-REBUILD to merge index blocks, reduce fragmentation, and improve query

    set lines 180set pagesize 500col instance_number for  99col module format a10col execs for 999,999,999col etime for  999,999,999.9col avg_etime for 999,999.999col avg_cpu_time for  999,999.999col avg_lio for 999,999,999.9col avg_pio for 9,999,999

Standard configuration of the Oracle listener and tnsnames file solves the problem that the listener cannot be connected. P. p1 {margin: 0.0px 0.0px 0.0px; font: 11.0px Helvetica} p. p2 {margin: 0.0px 0.0px 0.0px 0.0px; font: 11.0px Helvetica;