Oracle

What is the synonym "synonym"?(1) For some long names of objects (table, view, index, sequence, ...) ) do the subtraction, Replace with aliasesThe role of synonyms(1) Shorten the length of the object name(2) Easy access to other users '

There was a colleague, back and forth operation of the development and production of the database, the results mistakenly deleted the production of the database, that mood I think it is not common people can understand, although Oracle can have a

Review MySQL PagingUse the Limit keywordQuerying the top two records in the Users tableSELECT * from Users limit 0,2OrSELECT * from users limit 2;0 indicates the index number of the first record, and the index number starts at 02 indicates a maximum

1. View the database character setThe database server character Set select * from Nls_database_parameters, which is derived from props$, is the character set representing the database.　　Client Character Set Environment select * from

Test with a Scott user under the EMP table0. Environment setting--The following code is the display of the EMP table do set col empno for 9999;col ename for A10;col job for A10;col Mgr for 9999; Col hiredate for A12;col Sal for 9999;col comm for 9999

。Sometimes you want to force the deletion of an already connected Oracle user, cannot be deleted directly, can use kill session information.For example, to delete a connected SDE user today, you can delete a "connecting" user in the following ways.1.

Experimental purpose: Migrating an Oracle database from one machine to another (same as Linux platform), set to a different path, different instance nameSOURCE side:Oracle_base=/u01/app/oracleOracle_home=/u01/app/oracle/product/10.2.0/db_1Oracle_sid=

A friend who has been in touch with software development may know that Oracle can be used for data storage during development because Oracle has a fast processing speed and a particularly high level of security. But there is a disadvantage is the

Cast:Cast (the value to be converted as the type of the conversion) from to Binary_float, binary_double to CHAR, VARCHAR2 to Number to DATETIME, INTERVAL to NCHAR, NVARCHAR2

Use Xshell to connect to Oracle database server in win7 system, configure monitoring to use NETCA error [Email protected] ~]$ NETCAOracle Net Services Configuration:Error:nullCheck the trace file for

BackgroundTXT text for 900W data, the contents of the file are in the fields "|" Delimited, use Nevicat import too slow SolutionsUsing SQLLDR to import data,1) Setting up the configuration file Test.ctl[email protected] ~]$ cat Test.ctlLoad

deep understanding of latch in Oracle Serialization OverviewSerialization-the database system itself is a multi-user concurrency processing system, at the same point in time, there may be multiple users simultaneously operating the database,

Today, when you log in to the Oracle database EM, there is a picture.I found a lot of information and found no solution. After some research, I found that maybe I changed my computer's name yesterday, which caused my em to not log in.WORKAROUND:

1. CharFixed length, maximum of n characters.2. VarCharA variable string with a maximum length of n.     (n is an integer, different database, maximum length n different) char and varchar differences: varchar char saves space, but is slightly less

OracleSELECT * FROM (select rownum r,t1.* from tablename t1 where rownum m;Description: Filter The N records from the TableName table, starting with the M record.Mysql:SELECT * FROM tablename limit n,m;Description: Filtered from the TableName table,

The concepts and operations of partitioned tables are organized in the following ways: The concept of table spaces and partitioned tables The specific role of table partitioning Advantages and disadvantages of table partitioning

Functions in Oracle Oracle has built in a number of functions, different functions have different roles and usages, some functions can only work on one record line, some can work on multiple record lines,

Drop ViewAAA;Create ViewAaa asSelect '_BCDE'A fromDUALUNION AllSELECT 'ABCDE' fromDUALUNION AllSELECT 'Acbde' fromDUAL;SELECTA fromAaaWHEREA like '_bcd%';SelectA fromAaawhereA like '\_bcd%' ESCAPE '\';The character that follows the ESCAPE is a

Import Library:Prepare beforehand:1. Ensure that Oracle is installed correctly on the Linux server2, Oracle client, capable of connecting to Oracle on server.Start Step:1, CREATE table space (table space is more common will give you a script to

The PL/SQL language is the language that Oracle expands on SQL.1 procedures, functions, triggers are written in PL/SQL2 procedures, functions, triggers are in Oracle3 PL/SQL statements can be called directly in JavaSimple IntroductionWrite a stored