Database Administrator

We all know that the database files of the advanced version cannot be restored or appended to the lower version, because the format of the files of the higher version and the lower version is different. If you try to append or restore a database of

Reference: http://www.360doc.com/content/12/0403/01/9623234_200390473.shtml You can use the RMANDUPLICATE command to create a DuplicateDatabase Based on the backup of the target database (TargetDatabase) while retaining the target database ). This

1. Permission System introduction: The implementation of the MySQL permission system is relatively simple. The relevant permission information is mainly stored in mysql. User, mysql. db, mysql. Host, mysql_table_priv, and mysql. column_priv tables.

Mysqlslap is a benchmark testing tool that comes with benchmark after MySQL5.1. This tool can simulate multiple clients simultaneously and concurrently send query updates to the server, the performance test data is provided and the Performance

System Centos6.0 First, the following Backup terms are popularized: Hot Backup: Read and Write are not affected; Warm backup: only read operations can be performed; Cold backup: offline backup; read and write operations are suspended; We

Cold backup means that when the database is shut down normally, it will provide us with a complete database. Cold backup is a way to copy key files to another location. Advantages:1. It is a very fast backup method. You only need to copy files)2.

MySQL 5.6.10 official version has been released for many days. MySQL 5.6 adds the partition replacement function. Today, let's try out the partition replacement function.Two example tables: t1 is a partitioned table and t2 is a normal INNODB table.

The following is the configuration and monitoring of the SGA big page on the AIX platform. 1. Page size supported by aix AIX supports four types of page sizes, but not every hardware platform supports four types at the same time. You can use the

By default, MySQL processes "data out of bounds" and other abnormal data according to the following rules.1. For numeric data or time data columns, values beyond the valid range will be stage to the nearest value range boundary;2. If the string data

Not all tablespaces in the company's database are unlimted, so we still need to send an email to monitor the tablespace usage from time to time. The following are some documents I have used in my work after modification. My database version is 11.2.0

A basic principle for massive data performance optimization is "Partitioning"Also called "sharding). Partitioning is actually the principle of drawer in daily work and life: we put our items into multiple small drawers according to some logic, which

Recently, ORACLE databases in the unit are unstable. by querying the oracle alert Log, the following error message is displayed: Thread 1 cannot allocate new log, sequence 108922Checkpoint not completeCurrent log #1 seq #108921 mem #0: + DATADG/apts/

1) system table: stores all SQL system information. Stores metadata related to database services. The so-called Metadata refers to user databases on the data server, logon accounts on the database server, and tables in the database, which fields are

650) this. width = 650; "title =" mysql-ms1.png "src =" http://www.bkjia.com/uploads/allimg/131228/224554OO-0.png "/> Purpose: The robustness of the Master/Slave server settings is improved. If the master server fails, the slave server that was

SCANIP is a new feature of the ORACLE11G database. It can simplify the vip configuration of the client. during last year's ORACLE11 RAC environment, the company did not test SCANIP due to the hasty setup. This year, due to business needs, when you

1. Permission related: 1. ModifySQL security SQL code Alter procedure www SQL SECURITY INVOKER; Alter procedure www SQL SECURITY DEFINER; 1) the MySQL Stored Procedure specifies the actual user who executes the stored procedure by specifying the SQL

When I completed the student management system, I found that to use this software, the database data source must be configured. So I want to get a version that is out of the data source. Constructor: 650) this. width = 650; "src ="

Scenario:Data.txt source data: [INFO] 00:01:17 1610 FHR "row number = 24. view the volume data of the specified plan. plan No. = 121200102. "[INFO] 00:03:13 1610 FHR" row number = 24. view the volume data of the specified plan. plan No. = 121200103.

Today, some netizens are51cto Technical Forum inquiryDatabase-the automatic growth value is 12800%. for help, I saw this wonderful name, so I decided to go in and see if I could do my best. After reading this, I did not expect it to help me.

As we all know, SQL Server transactions are a single unit of work. If a transaction succeeds, all data modifications made in the transaction will be committed and become a permanent component of the database. If the transaction encounters an error