Database Administrator

MySQL has more slave database logs than the master database When chatting in the Group, a group member said that the master database of the MySQL production database is down, but the data of the master and slave databases is consistent, but the

Common Oracle and SDE maintenance commands-view tablespaces Previously, I reported a data update problem on the site. I thought it was caused by the full table space (the error was written in the previous blog article). Therefore, I remotely checked

MySQL Data Type Value TypeINTEGER (tinyint, smallint, int, bigint, mediumint ,)For integer types, there are three attributes: unsigned, zerofill (formatted output during query), auto_increment Float Type (float 4, double 8, real, double

Install Redis in CentOS6 I. Download redis Official website address: http://redis.io/ If make is not installed in the system, see Wget http://download.redis.io/redis-stable.tar.gzTar xzf redis-stable.tar.gzCd redis-stableMake MALLOC = libcMake

Redis master-slave cluster construction and disaster recovery deployment (sentinel) Redis has also been used for a while. Record the cluster construction and configuration details for later use.Outline Install Redis Overall Architecture Redis

Solution to Oracle11g CRS-0184 [Grid @ rac3 cssd] $ crs_stat-tCRS-0184: Cannot communicate with the CRS daemon. [Grid @ rac3 cssd] $ crsctl check hasCRS-4638: Oracle High Availability Services is online[Grid @ rac3 cssd] $ crsctl check crsCRS-4638:

Oracle: RETURNING clause RETURNING is usually used in combination with DML statements. (Insert update delete) Usage: UPDATE table_name SET expr1RETURNING column_nameINTO xxx INSERT: returns the added value.UPDATE: return the updated value. DELETE:

Comparison of several MySQL environment problems Sometimes there are environmental problems. comparison is a good method. If the comparison is proper, you can avoid repeated problems. You can infer some possible situations or problems based on the

Data Types of MySQL Learning I. Data Types 1. value types: TINYINT, SMALLINT, MEDIUMINT, INT, BIGINT, and DECIMAL2. Time type -- DATE, DATETIME, TIMESTAMP3. string type-CHAR, VARCHAR, TEXT4. Special types-ENUM and SETString case sensitive --

Upgrade Oracle 11.2.0.1.0 to 11.2.0.3.0 View the database version [Oracle @ RedHat6 ~] $ Sqlplus/as sysdba SQL * Plus: Release 11.2.0.1.0 Production on Fri Dec 6 21:12:32 2013 Copyright (c) 1982,200 9, Oracle. All rights reserved. Connected to an

Oracle Bug ORA-04043 Someone tested Oracle bug ORA-04043 in Oracle 11.0.2.0 under Win, and then carried out the test on his own machine, the test process is as follows: SQL> select * from v $ version where rownum = 1; BANNER--------------------------

MySQL monitoring tool-Innotop Innotop is a powerful MySQL monitoring tool. It uses perl to show the running status of MysQL servers and Innodb in text mode. Install innotop : Https://github.com/innotop/innotop Github provides two versions: The

Comparison between one-time transaction and CTE data insertion Sometimes we need to construct some data for testing, as shown below:IF OBJECT_ID (N 't14') IS NOT NULL BEGIN Drop table T14 END GO Create table T14 (t14_id INT) GO DECLARE @ I INT =

CentOS 6.5 system installation Oracle11.2.0.4 basic steps CentOS 6.5 system installation Oracle11.2.0.4 basic steps 1. Modify the hosts file (simple, not described in detail)Vim/etc/hosts 2. Modify the sysctl. conf file. Vim/etc/sysctl. conf Kernel.

Oracle 11G uses DG Broker to create a consumer uard Oracle 11G uses DG Broker to create a consumer uard 1. Environment: A. host environment: CentOS6.5 B. software environment: oracle 11.2.0.4 C. host information: DG1: 192.168.100.51 (Database sid:

How does MySQL manage multiple instances? MySQL can run multiple instances in two ways. The first is to start different processes to implement multiple instances. The second is to use a separate configuration file through mysqld_multi to implement

Differences between statement and preparedStatement [in jdbc] ① Syntax difference: · Statement is the parent class of PreparedStatement [developer generally uses the latter]· Different SQL statement locations:The usage of statement is as

When ogg is started, libnnz11.so: cannot open shared object file is returned. After the ogg software is decompressed and the correct permissions are granted, the following error occurs when ogg is started: [Root @ HWZX-DB-BI ogg] #./ggsci./Ggsci:

Only enable 10046 trace for a specific SQL statement Recently, I encountered an interesting problem: there is an SQL statement that runs for dozens of milliseconds most of the time, but sometimes the execution time of a certain time is longer than 2

Difference between Having and Where in SQL, sqlhavingwhere Description Where Select before grouping Having Having can select an aggregation function only after grouping.Eg: // Select count (*) from awhere a. a1> 0 group by a2; // However,