Database Administrator

Verify MyCAT ER sharding Here, we have constructed two tables. All the children's shoes familiar with Oracle know that dept (Department table) and emp (employee table), where deptno in dept is the foreign key of dept_no In the emp table. The

ORA-12154, ORA-12560 Solution Process Application Server: Windows Server 2008 R2 EnterpriseFault symptom: Project-side colleague reported application server program Connection database error: ORA-12560: TNS: protocol adapter Error 1. Fault

MySQL Master/Slave Failure Recovery using bin-log When MySQL Master/slave fails, first view the slave database show slave status \ G Remember the pos and binlog files of the bin-log (usually select the last point of the last pos for recovery) or

MySQL tmpdir Parameter Modification Today, I suddenly received an alert message saying that/the disk space usage exceeds the threshold. It was found that there were many abnormal SQL statements that could not be executed, resulting in continuous

MongoDB replication mechanism instance MongoDB master-slave replication is a master node that can replicate multiple slave nodes and master nodes. Here, one master node and one slave server use one database server to provide different ports. 1.

MongoDB sharding simple instanceParts Another type of cluster exists in Mongodb, that is, the sharding technology, which can meet the needs of a large increase in MongoDB data volume. When MongoDB stores massive amounts of data, one machine may not

Build an Oracle10g Database Based on LVM bare devices on Oracle Linux 5.11 Software: VMware11 Operating System: Oracle Linux 5.11x64Database: Oracle 10.2.0.5 x64Host Name: odb. test. localIP Address: 192.168.223.100 # the VM host network is

Oracle 11g installation diagram and related dependent libraries in SUSE 11 Installation environment Linux Server: SUSE11-linux 64/32-bit Oracle Server: Oracle11gR2 64/32-bit System Requirements Memory: physical memory must be higher than 1 GB

Verification of the MyCAT Character Set The default Character Set of MyCAT is UTF8. The following describes how to check the log to verify the effect of different MySQL client character sets and server character sets on MyCAT. There are three main

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

View in MySQL 1. What is a view? In general, a view is the result set returned after a SELECT statement is executed. Therefore, when creating a view, the main task is to create this SQL query statement. Ii. view features A view is a reference to

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:

Page processing of Neo4j graph data First, we will briefly introduce Neo4j. Neo4j is a high-performance NOSQL graphic database that stores structured data on the network rather than in tables, it is an embedded, disk-based, Java persistence engine

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--------------------------

In MongoDB, time stamps are converted to common date formats in batches. 1. mongodb traversal script provided on the official website:Official documentation: https://docs.mongodb.org/manual/tutorial/remove-documents/> Var arr = ["AB", "cd", "ef"]>

SQL Server attaches a database and reports error 5123. Recently, my computer has been upgraded from WIN7 to WIN10. After installing common software and SQL SERVER, attach some test databases and the following error is reported: Figure-1: An

Redis performance test Redis performance testing is achieved by executing multiple commands at the same time. Redis performance testing is mainly implemented through redis-benchmark in the src folder (in Linux)Syntax The basic commands for redis

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.

Error dirname in shell script: Invalid option -- B When writing a Shell script today, an error is reported during debugging. [Oracle @ smidb11 autoawrrpt] $. a. sh dirname: Invalid option -- B please try to execute "dirname -- help" for more

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: