Database Administrator

Solutions to frequent sleep processes in MySQL The company has a Linux server dedicated to running the company's WEB services. due to historical reasons, there are a large number of sites and pages, which often lead to a large number of sleep

Installation of MySQL automated O & M MySQL is usually installed using RPM or source code.RPM installation is fast and convenient. the disadvantage is that the installation directory cannot be customized. if you need to adjust the storage location

Common Oracle System packages and common methods 1. dbms_metadata.get_ddl: generate the ddl information of the database object: 2. dbms_stats is used to collect, view, and modify the optimization statistics of database objects. Exec

Two methods for processing the variant table (ORA-04091) in Oracle Oracle often used trigger often appears ora-04091 variant table problem, here bring two kinds of processing methods for your reference. -- ***** Example *****Scenario Description:-- 1

RMAN Restore terminated abnormally. Error: Cannot allocate memory Cannot allocate memory is reported during RMAN restore. Symptom:Channel ORA_DISK_1: restoring datafile 00030 to + TESTDG/rac/datafile/users.292.817416403Channel ORA_DISK_1: reading

Oracle 11g RAC listener offline After the Oracle 11g RAC listener has changed the network, the listener process offline appears, and the two nodes are switched frequently. Check the log/var/log/message to find frequent registration and revocation

Oracle batch update sequence Storage Preface: Sequence of Oracle (SEQUENCE) a schema object that generates a serial list of unique numbers for table columns. to use a sequence, your schema must contain the sequence or you must have been granted the

MySQL system variables (system variables), mysqlvariables MySQL system variables are actually some system parameters used to initialize or set the database's occupation of system resources and file storage location. These System variables can be

Configure statspack and racstatspack in Oracle RAC Environment Statspack is a product of the Oracle 9i era. It has a cross-milestone significance for monitoring and analyzing database performance and is the predecessor of AWR. After 10 Gb of Oracle,

Use commands to create an oracle11G database and an oracle11g Database This document describes how to create an oracle database that complies with the OFA specification using the create database Command of the oracle database. 1. Set the environment

How much do you know about PreparedStatement?Preface I believe everyone is familiar with the PreparedStatement. Why should I use PreparedStatement? Maybe you will answer PreparedStatement as a pre-processing statement, which can improve the database

[Oracle] OPatch upgrade, oracleopatch During the PSU upgrade, opatch prereq CheckConflictAgainstOHWithDetail-phBaseDir./12419378 Detection Error: Invoking prereq "checkconflictagainstohwithdetail" The location "./9352164/README.html" is not a

MYSQL Study Notes 3: Date and Time Functions, mysql Study Notes MYSQL study Note 3: Date and Time Functions 1. Get the function of the current date and the function of the current time /* Get the current date function and get the current time

Introduction to Oracle instance recovery and flashback, oracleflashback Instance recovery phase:1. data files are not synchronized 2. Roll Forward (redo)3. submitted and unsubmitted data in the file 4. Open the database 5. Roll Back (Restore undo) 6.

Optimize OLTP system performance by binding variables and variable oltp system performancePreviously, An OLTP database was optimized for a customer in Nanjing. A large number of query statements with very similar structures were executed in the

Basic functions in MysqlThe time function select curdate (); returns, excluding the hour, minute, and second select curtime (); returns 14:13:22, excluding the year, month, and day select now (); returns 10: 46: 17 select unix_timestamp (now ();

Risks of incorrect selection of Oracle Database Design field types, oracle Fields A hidden danger of inaccurate data types. The following constructs a table storage date field, one storage varchar2, and one storage date for a test. I have also

Mybatis dynamically transfers table names (also applies to dynamically transfers table fields) and mybatis Fields // Set the name of the map parameter, innerTable, and outTable. Public String sendDetail (){Pager = getStartPager ();If (null! = Msg &

Instance recovery and Oracle SCN, instance oraclescn A simple understanding of oracle's SCN is its own time function, just like the linux system's own time, oracle also has its own set of time. When you close the database cleanly, shutdown immediate

Connection sequence in the WHERE clause of Oracle performance optimization learning notes, oracle Performance Optimization ORACLE uses the bottom-up sequence to parse the WHERE clause. According to this principle, the join between tables must be