Oracle

Modify the field type of existing data in Oracle [SQL] www.2cto.com create table t_person (id varchar2 (200) primary key, name varchar2 (200), address varchar2 (200 )); [SQL] insert into t_person (id, name, address) values (sys_guid (), 'hangsan',

In linux, Oracle cannot be started due to IP address modification. The main issue is to modify the/etc/hosts configuration file. Configuration before modification: www.2cto.com 127.0.0.1 localhost192.168.2.50 CCXFIT-DBSERVER # The following lines

Oracle truncate table Truncate is a SQL statement used to delete data TABLE content: syntax truncate table name parameter name is the name of the TABLE to be truncated or the name of the TABLE to delete all its rows. The following describes the

The oracle produce synchronization intermediate database is used as an Internet system on an existing system. Considering the server pressure or the absence of conditions, it can directly connect to the database of an existing system. You need to

SQL in the special string truncation techniques in the preparation of SQL, will always encounter a special meaning of a field value, the interception of a piece of the value of the return, such as a string SSOC-XXX-13-001, now you need to return 13

In Oracle, the group by clause can be used in select statements to divide rows into smaller groups, and then the grouping function is used to return the summary information of each group. In addition, you can use the having clause to limit the

Oracle Database SQL single-row function-TRIM function of the character function can remove spaces of strings. For example: [SQL] select TRIM ('s 'from 'ssmith') from emp; -- delete the specified character and the result is: mith select trim ('oralce

Example of the change in the initial value when the parameter compress = y in EXP causes imp: Import/Export version, platform: 11.2, windows import/export version, platform: 10.2, linux 1. create a test table: [SQL] SQL> conn scott/xyc is connected.

The left and right connections in oracle saves the complex join statements (left join and right join) in SQL server, which are represented by a "(+. In the following experiment, query 1 and query 2 are equivalent, and query 3 and query 4 are

Write a script to start the database. Every time you open Linux, you always need to write duplicate operations. That is, start the listener, start the database, and view the database status. It is more convenient to write a shell script to control

Alter table open parallel operation use alter table open parallel first create a table create table a_test (name varchar2 (10) insert into a_test values ('aaa'); select * from a_test; NAME ---- aaa add an age and then use the parallel alter table

Common Methods for moving oracle files-moving tablespace files 1. querying the table space file name SQL> select d. name from v $ datafile d join v $ tablespace t using (ts #) where name = 'xport'; 2. Disable Database SQL> shutdown immediate; 3.

Oracle knowledge point summary (1) architecture: the database architecture refers to the composition, working process and principles of the database, and the organization and management mechanism of data in the database. The architecture includes:

AWR analysis: On a tall building, we can see AWR RoadAutomatic Workload Repository is an important component introduced by 10 Gb.Stores the detailed information and information about the database activity status in the recent period. The default

Export excel create or replace directory MY_DIR as 'C:/abc' in oracle; create or replace procedure export_data_out_excel/** use utl_file to write the data to the text file pfile_name: output file name. Pexport_ SQL: The executed SQL statement,

Rman restore recover C: \ Users \ Administrator> rman recovery MANAGER: Release 10.2.0.1.0-Production on Sunday March 31 20:10:53 2013 Copyright (c) 1982,200 5, Oracle. all rights reserved. RMAN> connect target \ target database password: connect to

The mechanism of the transaction concurrency control lock is to prevent the interaction between transactions and control concurrent access to ensure data consistency and integrity. When a transaction or operation attempts to prevent another

Oracle Database SQL statement exercises-preparationPrefaceI have been learning Oracle SQL statements for some time. I have always determined that the true learning is:It can be used in practice. Otherwise, it can only be explained that it is simple

Oracle TNS-04415 ErrorSaturday, March 30, 2013Error descriptionD: \ Users \ Elvis> netcaOracle Net Services Configuration:Configuring LISTENER: LISTENERServiceAliasException: unable to save service alias: TNS-04415: file I/O ErrorCaused by: java. io.

Use of some built-in methods in oracle 1. query a tablespace in a database: Use select * from DBA_INDEXES or DBA_OBJECTS 2. query database connections: select count (*) from V $ SESSION 3. query the maximum number of connections in the database: