Database Administrator

1. Create a directory for saving the backup file/mysqldata# Mkdir/mysqldata2. Create the/usr/sbin/bakmysql file.# Vi/backup/bakmysql. shInput (cyclically)Tar zcvf/mysqldata/mysql _ 'date-d today when running w'.tar.gz/var/lib/mysqlOr write

It is also supported! This is a database learning experience that I have summarized during my work and study. In fact, database learning is not as difficult as I imagined, it would be easier to become a DBA without involving the development of the

1. It should be easy to install MySQL, and I don't think there is much problem in the installation, so I will not talk about it much. Next let's talk about the configuration.2. Configure MySQL. Note that MySQL in Ubuntu only allows local access by

Sequence is a Sequence of numbers automatically added by the database system according to certain rules. This sequence is generally used as the proxy primary key (because it will not be repeated) and has no other meaning.Sequence is a feature of the

I have encountered such a question several times, but I cannot answer the question exactly each time. The answer is as follows: (forget to add)1. Database DesignTry to occupy less disk space for database design.1). Use smaller integer types as much

If a complex query of many tables is used, but no rows are returned, perform the following steps to identify the error: Use EXPLAIN to test the query to check whether a clear error has been found. Select only the columns used in the where clause.

Solutions to mysql Chinese garbled characters in php You have already set the default encoding of your mysql database. I have set it to gbk. Later, php showed that the results were garbled. In this case, you can add the following statement to the

In Ubuntu, MySQL only allows local access by default. If you want other machines to remotely access this Mysql database, you need to set something. Next we will step by step: 1. Configuration File Modification 1. # sudo vim/etc/mysql/my. conf

The processing logs cannot be retained on site, and the logs are written in memory. Give yourself a thought prompt. When a development database is started, an undo error is reported. The environment is Oracle 10.2.0.5 and aix 5308. Start the

In Ubuntu 12.04, MySQL is installed. After MySQL is installed, an error is returned when the character compilation is changed. I feel very depressed. Environment: Root @ ubuntu :~ # Uname-Linux ubuntu 3.2.0-23-generic # 36-Ubuntu SMP Tue Apr 10 20:39

Install and configure Oracle11g in the silent mode of the response File  1. Hardware requirements: Memory: grep-I memtotal/proc/meminfo requires at least 1 GB of memory Swap partition grep-I swaptotal/proc/meminfo If your memory is less than 2 GB,

There are three ways to access the Oracle database: the first is to directly access the shared memory of the database instance by the application process, and the second is to access the database on the local machine through the beq protocol, the

In Linux/Unix, apart from calling SQL, calling PL/SQL is also a common situation for DBA. The following mainly uses some examples to show how to call pl/SQL under shell. Other related references: Linux/Unix shell scripts call SQL and RMAN

In Oracle databases, each user generally has his/her own data storage space such as data table space, temporary tablespace, and index tablespace, and you cannot write it to other tablespaces at will. For example, we often see tables built on users

Due to demand changes, we need to change the field type of A type number (8, 2) to char The general idea is as follows: To change the name of a field of the type to backup, add a field with the same name as the field of the type to be changed (the

Oracle goldengate extracts data from the online log before extracting data from the archived log. This can be verified through the following method. 1. Insert test data to the master databaseSQL> insert into gg1.dept values (81, '1', '1 '); 1 row

Oracle 11g startup times The End Of The ORA-03113 communication channel file: SQL> startup; The oracle routine has been started. .... .... The database has been loaded. Ora-03113: End of the file for the communication channel ID: 5851

Oracle RAC add and delete OCR Oracle RAC backup and recovery OCR reference: Oracle Clusterware supports up to two OCR, one common OCR and one image OCR. if you use the External Redundancy method to store OCR, you can also add an image OCR. If you

1. TOP clause The TOP clause is used to specify the number of records to be returned. The TOP clause is very useful for large tables with thousands of records. Select top number | percent column_name (s)FROM table_nameExample: select top 2 * FROM

Recently, the alter log contains the VKRM error message, so I learned how to query it. From Oracle 11g, each day has its own windows and each of it has been specified default resource plan. this is something new for me too. so, I think that wocould