Database Administrator

1. the fastest possible implementation speed of Oracle Database paging is 1> 2> 3 First, layer-4 rowid is used.The second method is to use rownum to paging three layers (oracle stipulates that rownum can be used only once in each query)The third

There have been several online databases recently, and the hard disk is relatively tight, but it is not convenient to resize and transfer to other machines. However, data is important and needs to be backed up frequently. The earliest practice was

I. Install the operating system and patch packOnly GNOME Desktop is installed when the operating system is installedYum install gcc-c ++ libXp libaio make binutils openmotif setarch compat-db compat-gcc-c ++ compat-libstdc ++-devel rsh

After the 5.5 semi-synchronous replication, MySQL 5.6 has optimized and improved it. Two of them are important: 1. It should be a big pleasure for O & M personnel. After the master-slave switchover, in the traditional mode, you need to find the

For example, if you update the field tk_zyt_scenery_order in the table to t_advs_order, it is generally written as follows: UPDATE t_advs_order SET Attribute1 = (SELECT o. order_state FROM tk_zyt_scenery_order o WHERE o. order_id = 'on '),

Example: Remote Data Information: User name: interface Password: interface Ip: 10.7.237.17 Database: uidb Local database information: Username: jucks Password: jucks Database: gilbert 1. Check whether the user jucks has the dblink creation

Because the business needs to add a sequence every month, it is expected to use the job to create a regular one year each time. Some problems encountered when writing this job are recorded here. Step 1: Write the stored procedure for creating a

1. Use telnet to log on to 10.149.187.18. The username is root and the password is root & admin. 2. Enter su-Oracle. 3. Enter Sqlplus and the user name system and password oracle. 4. Use the following statement to delete the original tablespace:Drop

MySQLDumper is a PHP management script for backing up and recovering MySQL databases. It is easy to use. It is mainly used to manage MySQL databases for users who cannot directly operate the server, such as free space and shared hosts. Even if you

There are many online posts and comments about the failure of MySQL Service Startup (1067). It is difficult to tell the true or false, or whether it is the same as your own errors. With the lessons learned, it is necessary to declare in advance

I encountered a ORA-00257 error in the actual project (insufficient space error), by looking for information, the vast majority of said this is due to archiving too many logs, occupying all the hard disk space caused, you can simply delete logs or

Now all business systems are deployed with various types of monitoring for various aspects, so Oracle is no exception. We also need to monitor oracle, such as the instance survival status, the survival status of the listener and the running status

1. Environment preparation:Install three MYSQL servers.A 192.168.1.8B 192.168.1.88C 192.168.1.188 Ring Structure: 192.168.1.8 master 192.168.1.88 slave192.168.1.88 master 192.168.1.188 from192.168.1.188 master 192.168.1.8 slave 2. Change the

1. explain extended select .....Decompile the execution plan into a SELECT statement and run show warnings to obtain the query statement optimized by the MYSQL optimizer. 2. explain partitions select ....Used to EXPLAIN the Partition Table 3.

FlashbackFlash back is divided into three categories First,Flashback table Second,Flashback database Third,Flashback query (I), Enable and disable the recycle bin Alter session setrecyclebin = on; Altersession set recyclebin = off; Altersystem set

Databases are not archivedActiveStatus log corruption SQL> select * from v $ Log;  GROUP # THREAD # SEQUENCE # bytes members arc status FIRST_CHANGE # FIRST_TIM -----------------------------------------------------------------------------------------

Alter databasebackup controfile to trace as '/bk/col. SQL '; Consistency database stop destroys log files and Control Files Start Database SQL> startup Oracle instancestarted.   Total SystemGlobal Area 314572800 bytes Fixed Size 1219136

1. Enable archivelog SQL> shutdown immediate;SQL> startup mount;SQL> alter system set log_archive_dest_1 = 'location = d:/arc' scope = both;SQL> alter database archivelog;SQL> alter database open; 2. Backup Control File 2.1 generate the controlfile

Dbca or manual script can be used to create a database in Oracle. Version: oracle10.2.1. The method for creating a database by manual script is summarized as follows: Note: you must first create a directory and change it to your own directory; Step 1

1) constraints: constraints Imposed on tables to ensure data integrity and prevent data loss in associated tables;Common constraints:-NOT NULL-UNIQUE-PRIMARY KEY-FOREIGE KEY-CHECK When creating a table, specify the constraints. You can also add or