Database Administrator

By default, MySQL only allows local access. If you want other machines to remotely access this Mysql database, you need to set something. Next we will step by step: 1. Configuration File Modification1. # sudo vim/etc/mysql/my. conf Find

1. Oracle connection on aix1. su-oracle // enter the oracle user;2. export ORACLE_SID = house // specifies the instance. If multiple instances exist;3. sqlplus/nolog4. conn/as sysdba 2. ora-01033: oracle initialization or shutdown in progress, after

First download several compressed packages from OTN For: http://www.oracle.com/technology/software/tech/oci/instantclient/index.html Then select different downloads based on your platform. I installed them in rhel5, so I chose linux x86 and

To create a tablespace, you must first have the database orcl plsql tool to create an SQL window for execution. CreateTablespace orcl_tablespace datafile'D: \ Oracle \ product \ 10.1.0 \ oradata \ orcl \ orcl_data.dbf' Size1000 M;  -- Create the

The security management mechanism of Oracle10g listeners and oracle9i have been greatly changed. The Listener security mechanism uses the Password and Local OS Authentication methods. When Local OS Authentication is used, even if a listener password

/*The CHUNKS column indicates the number of available idle blocks in the tablespace (each idle block is composed of several consecutive Oracle data blocks). If there are too many idle blocks, for example, if there are more than 100 data files on

When declaring the VARCHAR2 variable, we can specify its maximum length unit as CHAR: v1 VARCHAR2 (2 CHAR); or BYTE: v2 VARCHAR2 (2 BYTE );, Most of the default values are not specified: v3 VARCHAR2 (2 );. So what are the differences between the

I wrote an Oracle Conversion Function and found that the data cannot be converted when the data is negative, because the data stored in the front-end of the service is 32 bits. When JAVA is converted to the INT type with a signed character, A

We all know that Latch is the mechanism that Oracle uses for serial control in memory. From 10g R2, Oracle introduced a new technology-Mutex. Mutex is not an invention of Oracle, but an underlying call provided by the system. Oracle only uses it to

Configure a retention (retention) PolicyThe backup set that does not comply with the policy is marked as expired. You can view and delete it.Three configurationsRman> the following three methods can be added after configure retention policy:1.

Slave database:SQL> alter database open read only;Alter database open read only*ERROR at line 1:ORA-10458: standby database requires recoveryORA-01152: file 1 was not restored from a sufficiently old backupORA-01110: data file 1:

Expdp and impdp are used only in Oracle10g. the following source database is Oracle10.2 and the target database is Oracle11.2.1. Create an expdp export directory on source database server.$ Pwd/Home/oraoms$ Mkdir exp_dir SQL> create or replace

Problem description: Export the table structures of all user tables in the Oracle database and store them in an Excel table. The storage information is shown in: Select a. TABLE_NAME, A. COMMENTS, B. COLUMN_NAME, B. comments from USER_TAB_COMMENTS a,

Finally, CentOS 6 was downloaded and installed on the virtual machine using Mini Desktop. VMWare-Tools installed Start installing Oracle 11.2 1. download the latest Oracle 11.2 installation package from the Oracle website. Because CentOS6 is

 1. Related Concepts The concept of Rowid: rowid is a pseudo column. Since it is a pseudo column, this column is not user-defined, but added by the system itself. Each table has a pseudo rowid column, but the table does not physically store the

Install the first Binary source code ready, you can download from the image Sohu: http://mirrors.sohu.com/ My website is mysql-5.5.15-linux2.6-i686.tar.gz,Linux version 2.6.18-164. el5 In actual work, the configurations of virtual machines may be

I. [Problem description] Recently, the customer suggested that the usage balance of the KC70 medical account is inconsistent with the account balance in KC04. Ii. [analysis process] According to the database backend package, the backend package

The cursor is the data extracted from the data table. It is stored in the memory as a temporary table. There is a data pointer in the cursor. In the initial state, it points to the first record, the fetch statement can be used to move the pointer,

1. Parameter files and server parameter filesA Parameter File is usually called an init file or an init. ora File. The default name is the init . ora text file.SPFILE generation PFILE: create pfile = '/tmp/initorcl. ora' from spfile;Server Parameter

After Oracle is installed, the installation is successful, but errors occur when dbca and netca are running.[Oracle @ db1 ~] $ Netca Oracle Net Services Configuration:## An unexpected error has been detected by HotSpot Virtual Machine:## SIGSEGV