Database Administrator

Undotbs01.dbf file too large solution Reduce the size of the UNDOTBS01.DBF file in the Oracle directory Log on to Oracle using the sys userMethod 1: reset the tablespace size Run Alter database datafile '/opt/oracle/oradata/res/undotbs01.dbf' RESIZE

Oracle uses sqluldr2 to export data Sqluldr2 isThe OCI-based text export tool is small and convenient. It is similar to the exp provided by Oracle and supports exporting custom SQL statements, local data, and client data. It is fast and efficient.At

Two auto-increment methods for Oracle Database primary key (SEQUENCE and trigger)1. Preparations Create an Oracle database table. In the user table SYS_USERS, user_id is the primary key. -- Create tablecreate table SYS_USERS( user_id NUMBER(9)

Deep understanding of Oracle sequence Oracle Sequence: Sequence creates, uses, modifies, and deletes data. Sequence is an object used to generate continuous integer data. A sequence is often used as a growth column in the primary key. It can be

MySQL conversion table Engine There are many ways to convert the table storage engine into another engine. Each method has its own advantages and disadvantages. Here we will introduce four methods: Select the priority (pt-online-schema-change>

Overview of MySQL btree Indexes Today, I have studied the B-tree index in mysql. Through this article, you can understand the principle of the B-tree index in mysql and the data retrieval process, different btree indexes in innodb and myisam engines,

MariaDB beginner management commands Earlier, we learned to install the MariaDB server on CentOS/RHEL 7 (SEE), which is now the default database of RHEL/CentOS 7. Now we will discuss some useful MariaDB management commands. These are some very basic

Mongodb installation and basic search operations: Learning and organizing (1), mongodb search **Install and configure MongoDB in windows: **Installation references: http://www.cnblogs.com/jiaxuekai/p/7204716.htmlHttps://jingyan.baidu.com/article/ed1

Redis persistence, master-slave and Data Backup (2), redis master-slave data backupRedis has been widely used in the project. To improve redis performance and reliability, we need to know and do the following:Common memory optimization methods and

Article 6: Composite data types-arrays, objects, and nesting, ElasticSearch uses a JSON structure to store data. A Key/Value pair is a JSON field, and a Value can be a basic data type or an array, documents (also called objects), or document arrays.

Configure using redis in Spring boot -- Annotation form, springredis -- Following the template encoding method in the previous article, we used redisEncoding format configuration (1)Encoding format (2) After in-depth study, we found that the

Python Development --- operate MySQL database, pythonmysql Core Blog content: Reference blog: https://www.cnblogs.com/anpengapple/p/7127580.html1. initial trial operation2. the user logs on to the MySQL database for the first time and causes SQL

SQL server permission management and SQL server permission management1. Set a Logon account to view only some databases Refer to tn view any database PermissionsUse sp_addlogin to create a login name-Basic: User Logon account-Basic123456: User Logon

Detailed description of redis self-starting configuration and redis STARTUP configuration I. Overview 1.1 Principles How does redis auto-start work? After the Linux system is started, a program will scan files under a specific directory and execute

Analysis of the use of exists and in MySQL, analysis of mysqlexistsin Exists External table query by loop one by one. Each query will view the exists conditional statement. When the conditional statement in exists can return the row of the record

Probably the most powerful jdbc DBManager in history, jdbcdbmanager Package com. lb. util; import java. SQL. connection; import java. SQL. driverManager; import java. SQL. preparedStatement; import java. SQL. resultSet; import java. SQL.

C # Upgrade with NewSQL -- TiDB entry,I. background During the previous attempt to CockroachDB (the portal here: http://www.cnblogs.com/Zachary-Fan/p/cockroachdb_net_csharp.html), it was found that migrating from a conventional RDBMS was almost

Covering indexes of MySQL SQL optimization and optimizing indexes of mysqlsql Content Overview Using the primary index to improve SQL query efficiency is a frequently used technique, but sometimes the execution plan provided by MySQL is completely

Global Database ranking in December: PostgreSQL steadily increases and postgresql steadily increases Author: Zhou Qi DB-Engines released the database ranking for January. Among the top 20 databases, Oracle ranked first, with Cassandra ranking 9th

MySQL database (python), mysql database python Installation tutorial original web site http://www.cnblogs.com/iscodercn/p/5488633.html MOOC video tutorial Summary Show create table provinces; view encoding, EngineInteger: tingint-> smallint->