Database Administrator

Vi/etc/my. cnf[Mysqld]Datadir =/var/lib/mysqlSocket =/var/lib/mysql. sock# Default to using old password format for compatibility with mysql 3.x# Clients (those using the mysqlclient10 compatibility package ).# Old_passwords = 1Table_cache =

Sqlplus/as sysdba > Select total. tablespace_name, round (total. MB, 2) as Total_MB, round (total. MB-free.MB, 2) as Used_MB, round (1-free.MB/total. MB) * 100, 2) as Used_Pct from (select tablespace_name, sum (bytes)/1024/1024 as MB from

Oracle function (converts the entire string to uppercase) NLS_UPPER (x [, y]) [Function] returns a string and converts it to uppercase; [Parameter] x struct expression [Parameter] Nls_param (optional) specifies the sort method (nls_sort = ).

We know that Oracle will switch logs when the current online logs are full or some conditions are met, or when logs are manually switched, even if the current online log group is from this log group to another log group, the log loop mechanism is

1) Preparations* FTP client software* Xmanager* Pl/SQL dev* 10gr2_db_sol [1]. cpio, database installer, applicable to SUN Solaris (iSCSI), Database Version 10.2. 2) create user groups and users1) Add a user group:Groupadd oinstallGroupadd dba2) Add

In general, CentOS has installed the libevent binary library by default, but no header file for development is installed.Therefore, you can use the following command to install: Yum install libevent-devel Next, you can download the latest memcached

The tnsping service name of the XP Oracle client is normal, but cannot be entered with SQLPLUS. The error message is: ORA-12514: TNS: The Listener currently cannot identify the request service in the connection Descriptor Check that the tnsnames.

* Environment: windowsXP + Oracle10gR2* AutoTRACE is a simple and convenient tool for analyzing SQL Execution plans and execution efficiency.*/ AUTOTRACE is an SQL * Plus function that automatically generates an execution plan for an SQL statement

Early in the morning, I found that all mysql files in the Data Directory had disappeared, and a cold sweat occurred. What happened !!??? Was hacked, or was mysql Data loss caused by restarting the server two days ago ??? What is the problem? go

1. Review In the previous article, we talked about the use of percona-xtrabackup software. This article describes how percona-xtrabackup achieves Incremental backup and recovery.2. Incremental Backup  How to Implement Incremental backup and recovery

For "ORA-01722: Invalid Number error" always encountered before, today again encountered! Cause: It is common to convert fields to the number type. For example, it is common to create a materialized view if a column needs to be converted to a

Today in the deletion of a large table column, accidentally DBA restart DB, and then execute the query, it reported the ORA-12986 error, first come to understand this error: ORA-12986: columns in partially dropped state. Submit ALTER TABLE DROP

1. Download MySQL 5.6Download Page: http://dev.mysql.com/downloads/mysql/this option is selected using Red Hat Enterprise Linux 6/Oracle Linux 6 (x86, 32-bit), RPM Bundle. Download to/root/Downloads "2. decompress the tar package

1. Bolb field description: Writing Blob fields is very different from writing other types of fields. Because Blob itself has a cursor, you must use cursor to operate blob. Therefore, before writing Blob, you must obtain the cursor to write data. How

In Windows, Oracle 11g cannot be started normally after a shutdown and cannot be started to the mount state: ORA-03113: end-of-file on communication channel Process ID: 4276 Session ID: 1286 Serial number: 2 Find the trc file of the corresponding

I. Basic principles of mysql master-slave replication:This experiment demonstrates the asynchronous replication of mysql. What is asynchronous replication? That is, when a statement starts, the master server does not wait for the execution of the

In March January 2014, the database needs to be moved from the original storage platform to the new storage platform due to changes in the hardware environment. That is, change the underlying storage medium of the database. The following describes

Percona is a branch of mysql. I believe many of my friends are familiar with it. percona-toolkit is a toolkit launched by percona. It contains a lot of useful and useful mysql maintenance kits, I started to learn about this tool today. The first

I. Usage The package UTL_FIle is used to read and write files in the operating system, provided that the Directory object and authorization are created first. Then you can use the types, procedures, and functions provided in the UTL_FILE package to

In the morning, you receive an alert email from a Linux server disk and an email from the monitoring Alert Log program. After the check, it is found that there is no space for a partition in the Linux server. The main reason is that the programmer