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 =

SQL code Select decode (INSTR ('initateaaaa FLOOR ', 'aaa'), 1) FROM DUAL The format of the INSTR method is INSTR (source string, target string, start position, matching serial number) For example, in INSTR ('upgrade FLOOR ', 'or', 3, 2), the

DUAL table:Dual enables the system table, whose owner is the sys user. Cannot be deleted.All users can access it.A dual table is also called a virtual table.There is only one field in the dual table. This field makes dummy. SQL> DESC DUAL;Is the

This form is generally used for Oracle paging.SELECT * FROM(Select a. *, rownum rFROM(SELECT *FROM ArticlesOrder by PubTime DESC)) BWHERE r And r> PageLowerBound;In many cases, you do not need to sort data. Instead, you need to perform multi-table

1. Write the URL for connecting an application to Oracle racJdbc: oracle: thin: @ (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP) (HOST = 192.168.30.52) (PORT = 1521) (ADDRESS = (PROTOCOL = TCP) (HOST = 192.168.30.51) (PORT = 1521) (LOAD_BALANCE = yes)

I recently used MySQL databases for Linux projects, but when I remotely connect to MySQL, I always reported erro 2003: Can't connect to MySQL server on '100. 87. ***. * ** '(111). The solution was found several hours yesterday, as shown below: 1.

SQL> create tablespace test datafile 'y: \ test. dbf' size 20 M; The name of the actually created tablespace is TEST. Execute the following three commands to delete the tablespace: SQL> drop tablespace test; The tablespace has been deleted. SQL>

The following is a reference clip:ErrorCode: 1418ThisfunctionhasnoneofDETERMINISTIC, NOSQL, orREADSSQLDATAinitsdeclarationandbinaryloggingisenabled (you * might * wanttousethelesssafelog_bin_trust_function_creatorsvariable)(0 mstaken) The solution

Export the database as follows: Enter cmd in the command line to enter the DOS window. Enter exp ccsbi/ccsbi_jyfx@ Ccsbi_55File = d: daochu. dmp ignore = y To export the entire database. Data export:  1Export the database TEST completely, and

This article describes eight common shell scripts for monitoring data. First, I reviewed some common DBA Unix Commands and explained how to regularly execute DBA scripts through Unix Cron. There are also a lot of similar articles on the Internet,

I. Create a test table Create table job(Jobid SERIAL primary key,Jobdesc json) 2. Selector -> (Return object type)-> (Response type)#>> (Select array type) 3. insert, select, update, and delete operation records 1. Insert record Insert into job

Because a large amount of data exists in text files and needs to be imported to Oracle, we are lucky to have access to the arms SqlLoader. Run the sqlldr command on the host where Oracle is installed.Sqlldr You will see instructions on this tool:

Hibernate supports third-party connection pools. the officially recommended connection pools are C3P0, Proxool, and DBCP. Note the following three points when configuring the connection pool: 1. Apche's DBCP is supported in Hibernate2, but it is no

Knowledge Popularization: 1 normally, we use the explain plan for, set autotrace, and utlxplan methods to view the execution plans. They are all the execution plans generated by optimizer and do not fully conform to the execution paths of Oracle

Lab environment: Operating System: Red Hat Enterprise Linux ES release 4 (Nahant Update 6) Database: Oracle Database 10g Release 10.2.0.4.0-Production 32bit When shutdown immediate (in fact, the stop_oracle.sh script is executed to close the

In recent times, many netizens raised questions about Listener Configuration, and the Client cannot connect to the Server ). This article briefly introduces the Listener Configuration, provides detailed configuration methods for PL/SQL Developer to

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

Maintain the MySQL database 1. database user authorizationGrant permission list on database name. Table name to user name @ Source Address [identified by 'Password'];Permission list: Used to list various database operations authorized for use,

For the past two days, I have been reading the table space section in the document. I am very ashamed to say that after continuous attempts, I finally completed an experiment on the imperfect transmission of tablespaces. 1. Introduction to the

Some customers responded to the slow query of website background orders and obtained the related SQL through the program.ExplainExplain select distinct (o. orders_id), o. oa_order_id, customers_email_address, o. order_type, ot. text AS total_value,