Database Administrator

Set the maximum number of MySQL connections in CentOS to 1040 too persistent connection Set the maximum number of MySQL connections in CentOS to 1040 too persistent connection When the maximum number of connections is small, the error "1040 too

SPFILE causes Oracle Database startup failure After the server is powered off and restarted, it is reported that Oracle Database Service cannot be started, on the server to use as sysdba login to connect to a null instance, use startup times 'ora-24

How to log on to and connect to the target database using RMAN How to log on to and connect to the target database using RMAN I. Method 1: A) [Oracle @ odd-oelr4u8 ~] $ Rman target sys/oracle @ PROD1521 catalog catalog_admin/catalog_admin @ PROD21521

After MySQL is installed, only the following hosts are recognized: localhost and 127.0.0.1. The only hosts recognized after MySQL is installed are localhost and 127.0.0.1. If you want to allow the IP address on your machine to log on normally, there

Oracle uses with as and hint materialize to optimize SQL to solve low FILTER efficiency During project creation, a page uses SQL statements similar to the following to query data, I replaced the table name and field in the project with the system

Oracle Spatial Database Function usage Recently, I have been using Oracle's spatial database for some spatial data processing and analysis functions. I wrote this article mainly to take notes. After all, good memory is not as bad as writing. First,

Detailed description of the installation process of Oracle 11g Database in Linux Oracle11g database installation specification in LinuxI. Instructions on downloading Database Installation Software (including patches) How to install software in

Oracle case study ORA-01722 troubleshooting 1.1. ORA-01722 Date: Environment: test environment [Scenario description] During Database Upgrade, execute SQL> @? /Rdbms/admin/catupgrd. SQL script reports an error and exits. Install Oracle 11gR2 (x64)

Solution to impdp exceptions and interruptions Check the database load today and find that the cpu consumption is abnormally high. There are many dw processes, but the impdp process does not exist.Check the process of datapump and find a large

Undo tablespace and redo logs Differences between undo and redo and their respective functions 1. Features of undo data: 1. It is a backup before data modification, mainly to ensure the user's read consistency 2. generated when the transaction

Application of cursor and recursion in Oracle Functions Most programmers may be familiar with recursion in code, but it is rare to write a recursive estimate in a stored procedure or function. Today, we have encountered an example of using recursion

Oracle Database Development In the Oracle database system, tables are the basic objects of databases, and all data in the database exists as tables. Environment-Oracle 11g I. Table typeCommon tables in Oracle Database systems include: heap

Full version of MySQL5.6 cluster configuration under Redhat6.5 1. Prepare three servers 2. Install the Linux operating system for the three machines respectively (Oracle Linux/RHEL 6.5 x86_64bit) 3. Separate IP addresses Management node 192.168.1.110

In-depth Oracle RMAN backup analysis-online backup RMAN> backup database plus archivelog; This command will trigger the following operations: 1. The process uses the alter system archivelog current command to complete log switching. 2. The process

[Oracle] ROWNUM and paging Rownum is a poor Oracle database, and its order increases progressively according to the order in which records are obtained from the table. Note that because records are stored unordered In the table, therefore, you

Clever Use of xmltype to parse clob data For clob data, xml format is used in many cases, but data query and processing is always insufficient. When conditions permit, if xmltype can be cleverly used for data processing, it is accidentally a

How to solve the problem that the maximum number of MySQL connections exceeds the limit Recently, the User database name has already more than 'max _ user_connections 'active connections error is reported on the website. It is necessary to study

[RMAN] Recovering data from RAC to a single-host environment Data Recovery from RAC to a single-host environment I. Summary With more and more RAC environments, the need to migrate RAC data to a single-host environment also increases. How can we

Abmr: test the automatic block Recovery feature and abmr test feature Abmr: test the automatic block Recovery feature Reference Original:ABMR: How to test Automatic Block Recover Feature (Doc ID 1266059.1) Applicable:Oracle Server-Enterprise Edition-

Oracle GoldenGate (hereinafter referred to as ogg) synchronizes data between databases of the same type on Heterogeneous OS ., Goldengateogg Oracle GoldenGate (hereinafter referred to as ogg) synchronizes data between databases of the same type on