Database Administrator

Syntax: Test_expression BETWEEN begin_expression AND end_expressionFor example: The database AA table has an AA_RQ field, which is declared, Oracle AA_RQ VARCHAR2 (8 ),SQL Server AA_RQ VARCHAR (8 ),The following two statements have

The previous articles are based on what you see and know, and are integrated with the predecessors to gain a preliminary understanding of the concept of big data. In the next four articles, we put aside the concept and basic knowledge of big data

Impdp import data, ORA-39082 ORA-39083 error number, the object cannot compile after the import can be compiled object to try: alter view view_name compile; if the error: Use show errors to locate the source of the problem, whether it is a

Start database: Start db2 service: db2start activate database instance: db2 activate database View activated database: db2 list active databasesShut down database: Invalid database instance: db2 deactivate database shut down database Service:

Install configuration parameters [root@monser Percona-Server-5.5.34-rel32.0]# cmake . -DCMAKE_INSTALL_PREFIX=/service/mysql -DMYSQL_DATADIR=/data/mysql -DSYSCONFDIR=/service/mysql -DMYSQL_UNIX_ADDR=/data/mysql/mysql.sock

I/O statistics for tablespace in the oracle database during the last two hours -------------------------- ------For single instance---------- Select e. tsname,Sum (e. phyrds-nvl (B. phyrds, 0) reads,Sum (e. phyrds-nvl (B. phyrds, 0 ))/(Select

Http://www.infoq.com/cn/news/2014/01/12-free-and-open-source-nosql Naresh Kumar is a software engineer and enthusiastic blogger who is very interested in programming and new things and is very happy to share technical research results with other

Show status like 'value'; query the performance of the MySQL database. Value Parameter Connections: Number of times the MySQL server is connected Uptime: MySQL Server launch time Slow_queries: Number of slow queries Com_lelect:

EXPLAIN PLAN-This command is used to generate an SQL statement execution plan, but the statement is not actually executed. Dictionary View-In the oracle dictionary view, we can query the execution plans of SQL statements that have been executed

The session has been changed.Used time: 00: 00: 00.01SQL> select * from cfms_questions;Row 4587 has been selected.Execution Plan----------------------------------------------------------Plan hash value: 3912515109Bytes -------------------------------

Range Step 1: Apply the correct index Make sure that each table has a primary key.   Step 2: create an appropriate overwriting Index SalesPersonID Sales ProductID 112 NCLIX_Sales_ProductID Use Database adjustment

References involved in this descriptionBind variables and their advantages and disadvantagesOracle hard parsing and soft ParsingOracle variable bindingWhat does SQL Tuning Advisor (STA) do?Use SQL tuning advisor (STA) to automatically optimize SQL

In the application of the MySql master-slave replication architecture, after various exceptions occur in the running DB for a long time, there may be inconsistency between the master and slave databases, and occasionally an error occurs in the same

Mysql supports multiple storage engines. When processing different types of applications, you can use different storage engines to improve application efficiency or provide flexible storage. Mysql storage engines include MyISAM, InnoDB, BDB, MEMORY,

Splits strings. MYSQL version. Because MYSQL does not support recursion and does not support returning results of the table type, the code is cumbersome. I use two functions and a stored procedure. -- Obtain the total number of

Not only does it not help, but it also wastes a lot of manpower and time costs, and may even drag the server downTherefore, when we accept the optimization of an SQL statement, the first thing is to understand where the query problem is?Is it IO? Is

Many DBAs often encounter database I/O bottlenecks during database management. When the hardware cost is limited, there are two solutions to this bottleneck: Increase the memory; the second is to add Disks without adding machines ). Whether it is