Database Administrator

NUMBER (x, y) Data Types in Oracle databases Test preparation Analyze and Experiment Processing of 1 decimal part 2. Maximum value that can be saved 3. Minimum value that can be saved Summary The NUMBER data type of Oracle

Quick Reference for installation, deployment, and configuration of a single Oracle 11g instance on Linux 1. re-build the Oracle user group of the host and standardize uid gid to ensure the permission specification for shared storage mounting or

Detailed process of using mysqld_multi to deploy a single-host multi-instance With the development of hardware, multi-core Linux systems have become a general trend, while MySQL is a single-process multi-thread, so the exploitation of multi-process

New Features of Oracle 11G: collecting multi-column statistics Generally, when we submit an SQL statement to an Oracle database, Oracle selects an optimal method for execution, which is achieved by the Query Optimizer. CBO (Cost-Based Optimizer) is

Summary of Oracle 11gR2 RAC cluster Service Startup and Shutdown Introduction: the source of this article is that one of my students recently set up a RAC cluster in the company, but the sequence and principle of its startup and shutdown are not

SQL modifies the field value in the loop, and SQL modifies the field in the loop Looking for a section on the website does not meet your requirements: This program is used to automatically number an empty field. (when the system is using this

How to view the physical file storage location of the MySql database I want to export the database file in mysql, but I cannot find it. I say there is a path in the configuration file on the Internet, but I open my configuration file and all the

Question 8: MySQL ---------- Duplicate Emails, email Suppose that a website contains two tables,CustomersTable andOrdersTable. Write a SQL query to find all customers who never order anything. Table:Customers. +----+-------+| Id | Name |+----+-----

SQL error 1403: ogg synchronization, 1403ogg An error occurred while synchronizing data to the target: 09:33:33 ERROR OGG-01668 Oracle GoldenGate Delivery for Oracle, repraca. prm: process abending.09:39:33 INFO OGG-00975 Oracle GoldenGate Manager

MySQL Error Query database. Causejava. SQL. SQLException: Incorrect key file for table '/tmp/# SQL _181c,      1. The developer gave me the following background error: Error Query database. Causejava. SQL. SQLException: Incorrect key file for

ORACLE-012: Automatic varchar2 and number conversion for numbers only in oracle, oracle-012varchar2 When an association query is used, the fields in the two tables define different types. One field is of the varchar2 type, and the other is of the

Use sqlplus return output "^ H" in X-manager to solve the problem. x-managersqlplus Original Works are from the blog of "Deep Blue blog". You are welcome to repost them. Please indicate the source when you repost them. Otherwise, the copyright will

MySQL Data Type MySQL numeric data types can be roughly divided into two categories: one is an integer, and the other is a floating point or decimal. Many different subtypes are available for each of these classes. Each subtype supports data of

Redis memory optimization, persistence and master-slave replication, redis memory optimization master-slaveConfiguration of memory optimization parameters of apsaradb for Redis, advantages and disadvantages of each persistence mode, principles of

Oracle tables cannot be DDL and stored procedures cannot be used to create processing methods, oracleddl In the process of data migration, we will face two common hang scenarios: 1. You cannot modify or increase the length of a field in a table. 2.

An error occurred while using mybatis to operate on the stored procedure.An error occurred during project development: org. springframework. jdbc. badSqlGrammarException: ### Error querying database. cause: java. SQL. SQLException: ORA-06550: 8th

A list of MySQL index types enables MySQL to run efficiently. Index is the key to quick search. The establishment of MySQL indexes is very important for the efficient operation of MySQL. The following describes several common MySQL index

Common commands for create table and Common commands for table Create table students (stuID integer not null, stuname char (30) not null, sex int not null); create table students (stuID integer not null, stuname char (30) not null, sex int not null,

Oracle modifies the column type. oracle modifies the column type.1. If the field data is empty, you can directly execute the following command regardless of the field type:Alter table tb modify (name nvarchar2 (20 ));2. If the field has data, you

Mysql 5.6 and mysql5.6Limits in MySQL 5.6Sql Join restrictions:  Database and table quantity limit: The table size of a Mysql database is generally determined by the size limit of a single file in the operating system, not by the mysql kernel; File