Database Administrator

After the database is created, it is not in archive mode by default. To use RMAN for hot backup, you need to manually switch the database to archive mode. Generally, switching the archive mode is performed when the database is in the mount exclusive

Corrupt non-current online logs 1. Start the database, encountered a ORA-00312 or ORA-00313 error, suchORA-00313: open failed for members of log group 1 of thread 1ORA-00312: online log 1 thread 1: 'd: \ Oracle \ ORADATA \ TEST \ REDO01.LOG'Here we

Introduction: Two installation methods: Binary File Installation andCompile and install(This article uses the binary installation method. If you are interested, try to compile and install your own shoes) Environment Ubuntu-11-10 32BitPreparation 0.

Test environment: Oracle 10g 1. method 1 MD5 Encryption Create Or Replace FunctionFn_md5 (input_string VARCHAR2)ReturnVarchar2 IS Raw_input RAW (128): = UTL_RAW.CAST_TO_RAW (input_string ); Decrypted_raw RAW (2048 );

In the RAC environment, the undo tablespace is too large: SQL> conn/AsSysdba Connected. SQL>SelectInstance_number, instance_nameFromGv $ instance; INSTANCE_NUMBER INSTANCE_NAME ------------------------------- 1 unipsms1 2 unipsms2

PS: MySQL 5.5 series has become a stable version for some time, but according to my survey, it is still dominated by the 5.1 series in the production environment. In large Chinese companies, it is only determined that Jinshan is using 5.5. Several

LIKE fuzzy query The wildcard characters "%" and "_" can be used for character matching: %: Represents any character, including zero; _: Represents any character; ConnectedToOracleDatabase11g Enterprise Edition Release 11.2.0.1.0

MongoDB is a NoSQL database system. A database can contain multiple collections, each of which corresponds to tables in a relational database; A set of records identified by columns can be stored in each collection, and columns can be freely defined

Many databases are supported in php, but when combined with the best database mysql, IT and linux, apache, and php constitute a LAMP system. Php performs the following operations on mysql: connect to mysql database --> select database --> Execute

Today, I searched for data in the Oracle database and encountered a table with a character type of CHAR [2000]. Due to the length of the character, it cannot be retrieved using String. After google Baidu found that the CLOB type can be used. The

Here, we will talk about the processing of all nouns in Oracle10g. The following string contains all nouns in one of the words. BeginDbms_output.put_line ('1' | 'nimeng's dog ');End; Execution error: ORA-01756: the string in the brackets does not

Oracle LISTENER does not listen to Oracle instances. solution: LISTENER =(DESCRIPTION_LIST =(DESCRIPTION =(ADDRESS = (PROTOCOL = IPC) (KEY = EXTPROC1521 )))(DESCRIPTION =(ADDRESS = (PROTOCOL = TCP) (HOST = qihezhiye-PC.connectify) (PORT = 1521

In addition to the preceding view, Oracle also has a set of virtual tables used to record the current database activity. As the name suggests, dynamic performance tables are not real tables. Therefore, not all users can access these tables. However,

I. pg_class: The system table records metadata of data tables, indexes (still need to see pg_index), sequences, views, composite types, and some special link types. Note: not all fields make sense for all object types. Name Type

Previously written: This operation adds uppercase letters. DELIMITER $ USE't _ girl $ DROP FUNCTIONIf exists 'func _ rand_string '$ CREATEDEFINER = 'root' @ 'localhost'FUNCTION'Func_rand_string '(f_num tinyint unsigned, f_type

We have the following requirement: create two users in the database. User A creates some views and directly accesses the tables in one mode in the database, and access tables in other databases through the database link. Another user B can access

When backing up archive logs in Oracle databases, archive log files stored in the last few days are not deleted. For example: Backup archivelog all; Delete noprompt archivelog all completed before 'sysdate-7'; Save the archived logs for seven

MySQL provides the master-slave replication function, which is similar to Oracle's slave uard. However, configuration and management are far simpler than slave uard, and there is no so-called physical slave database or logical slave database, there

Our application developers found that the execution time of an SQL statement when binding a variable is much slower than when not binding a variable, even slowed down to dozens of times. In the application, if the executed SQL statement is not bound

It is convenient to connect to the MySql server using Jdbc. First, import jdbc to the project or put jdbc into ClassPath. Here, I use Eclipse to directly import the jdbc jar file. Then, the DriverManager is developed, And the froName of the Class is