Database Administrator

Because highly available database servers may rarely stop, SQL Server's log files will grow very large. In this way, it is difficult for DBA to use error log to find information, and the performance will be affected when the log is large.  We

Starting from Oracle10g, sqlplus provides a parameter option-prelim, which is used when the system has hang. We can connect to SGA instead of the database, that is, no session is created. 1. Follow these steps to obtain system

Introduction: We may not be familiar with the range, hash, and list partitions of Oracle, but there may be many questions about what scenarios each partition applies, so what should we pay attention to when selecting different partitions? Why? What

Cursor Concept A cursor is a memory Workspace of SQL, which is defined by the system or user as a variable. A cursor is used to temporarily store data blocks extracted from the database. Why use a cursor? The data in the database is stored in the

Prerequisites for Database Import and Export: 1. Install the Oraclek client or server locally. 2. connect to the target database through the NetConfiguration Assistant provided by oracle. The first step is needless to say. The second step is to open

Task Description: Copy all table space wy content to table space tietong. Procedure:1. First, install Oracle locally. 2. Use the Net Configuration Assistant to create a local Net service for the CMSTEST database in 10.153.246.149. the username and

Summary of Oracle listener problems: 1) Oracle listeners cannot be started normally after the system is shut down and restarted abnormally. You can manually modify the settings and use static registration listening:For example:# Listener. ora

Dynamic SQL syntax Only when running can Oracle check whether its format is correct The INTO and USING clauses are optional. If the SQL statement is a query statement, we can use the INTO clause. The INTO statement is used to receive the record

View the value of the environment variable used by an Oracle process. When nls_lang is null, we want to know the default value. When installing the version, we want to know that a process is generated by the database of that version, we can use the

View the redo log switching frequency of Oracle The two SQL statements have the same principle, and the second uses the statistical function. Time unit: minute Method 1,Select * from v $ log a where a. THREAD # = 1; Set line 200Select B. SEQUENCE #

Batch update Optimization for Oracle 10g large tables. In fact, 7 million of the tables are not big tables and are enough for testing. I. t table informationSQL> alter table t add is_del number (1 );SQL> alter table t modify is_del default 0; SQL>

The error message in the log is as follows:Sun Sep 02 01:29:47 2012Global Enqueue Services Deadlock detected. More info in file/U01/app/11.1.0/diag/rdbms/zzbrac2/zzbrac21/trace/zzbrac21_lmd0_11802.trc.Sun Sep 02 01:30:30 2012Thread 1 advanced to log

Environment: Oracle 11g R2 + SQLPlus Problem: create user, a ORA-01950 error occurred while creating the table space "system" has no permission Solution: The permission issue is obvious. The permission granted after the user is created is

[Oracle @ www.bkjia.com ~] $ Export ORACLE_SID = + ASM2[Oracle @ www.bkjia.com ~] $ AsmcmdConnected to an idle instance.Sh:/u01/app/oracle/product/11.2.0/db_1/bin/clsecho: No such file or directory This error is caused by an incorrect environment

According to the official Oracle documentation, the database character set cannot be changed after it is created. Therefore, it is important to consider which character set to use at the beginning of design and installation. For the database server,

Company Daniel asked keepalived to build high-availability MySQL. He saw a complete article on the Internet, so he followed the footsteps of his predecessors and added his own supplement. The environment topology is as follows: MySQL-VIP: 192.168.1.1

Rollup is an extension of group by, which performs subtotal and total operations. cube contains rollup, which is a more granular subtotal and total. When there is only one field, rollup and cube are the same. You can use grouping to test rollup and

Create a job in Oracle: Create table date_log (create_date date constraint create_date_pk primary key ); Create or replace procedure create_date_log_rowIsBeginInsert into date_log (create_date) values (sysdate );End;/Call create_date_log_row

1. Basic Steps for copying It takes only three steps to create a simple copy. Configure a server as the Master database, that is, the Master database. Configure another server as the slave database, that is, the slave database. Connect the

View existing VG # Lsvg Rootvg Oravg Datavg   View the usage status of each VG # Lsvg oravg Focus on several values Pp size: 512 megabyte (s) Note: SIZE of each PP FREE PPs: 147 (75264 megabytes) Note: number of available pp and Space # Lsvg