Database Administrator

Introduction to Oracle Database and InstanceIntroduction to Oracle Database and Instance Database: it consists of a series of files stored on the disk. These files are used to store data. Database instance: it consists of a series of memory

MySQL version upgrade record /*************************************** **************Upgrade MySQL 5.6.19 to 5.6.21 **************************************** *************/Backup is required before upgrade! ---- 1. view the data directory location of

Example of Oracle full-text index performance advantages 1. Experiment description: Operating System: rhel 5.4x86 Database: Oracle 11g R2 Ii. Procedure: 2.1 create a t_btree table and create a B-Tree index. The index key is object_name: SQL> create

Oracle static listener registration details There are a lot of articles on Oracle listening for static registration on the Internet, but most of them are just a simple introduction. There are no detailed examples. Here, we will combine Oracle 10gR2

Introduction to common Oracle data dictionaries A data dictionary is a group of tables and view structures in which Oracle stores information about database objects. It is used to describe data. For example, the Creator information, creation time

Introduction to Oracle instance recovery and flashback 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. submit data in

Oracle control file multiplexing 1. Oracle control file multiplexing 1. show parameter control-- View Control File InformationShow parameter spfile-- Check whether spfile exists.Create pfile from spfile;-- Generate pfileShutdown immediate-- Close

HP-UX install MySQL 1. Environment Introduction HP-UX B .11.31 ia64 Operating System Installation medium: mysql-5.1.48-hpux11.31-ia64-64bit.depot.gz 2. Installation Process (1) Create mysql users and user groups # Groupadd mysql # Useradd-g

Oracle Character Set Analysis There are many types of character sets. The first character set was ASCII. Since the number of characters supported by ASCII is very limited, many encoding schemes, such as Unicode, were introduced later. Unicode is a

Set RowCount and top n, setrowcounttop Sometimes, if n in top n is a variable, you need to use: declare @count1 intset @count1 = 8select top (@count1) * from MyTable If set RowCount is used, the same effect can be achieved. declare @count1 intset

[MongoDB] The description of index (1), mongodbdescription From this blog, we start to talk about the index in mongo Database, which is similar to the traditional database. generally speaking, if the index need to be created in the traditional

Develop CRUD with Mybatis annotation and crud with mybatis Annotation The previous article demonstrated how to use XML to operate Mybatis to implement CRUD, but writing a large number of XML configuration files is very annoying. Therefore Mybatis

[Mongo] group statistics time: aggregate, group, distinct, mongoaggregateSome records recorded by date in development require statistics in various dimensions, such as day, month, year, and hour ,.. For Grouping statistics, some fields need to be de-

Earlier oracle client versions cause bad SQL and oraclebad Environment: The production system is a 10 k OLAP system for online users (11 gb rac dual-node). One day, user units found that scanning programs were slow. View monitoring,Node1, high IO

How can I view others' QQ records? QQ1622863529Query serviceConsult QQ: 1622863529 to query QQ chat records, chat content queries, QQ audio queries, video content queries, delete QQ chat records, modify QQ chat records, and delete chat records with

One-to-one relationship in Hibernate association relationship ing, one-to-one relationship in hibernate There is a typical one-to-one relationship between people and ID cards. One of the two ways to implement one-to-one association ing is based on

Database Design-EAV (entity, attribute, value), eav entity There is such a business that is used by customers to record what they do every day. Because it is very professional, professional record books are required. There are more than 20 such

First understanding of MySQL stored procedures, mysql stored proceduresStored Procedure is a set of SQL statements for specific functions. It is compiled and Stored in the database, you can call and execute a stored procedure by specifying its name

C # summary, I remember that when I first started the mentoring meeting and talked about the progress, master learned C # And Dawei made meeting records. We didn't know how to write them. We were so wide-eyed that we had to ask Master, now I have

Rman (lower), rman (Backup Control File Method 1: automatic backup using the RMAN Control FileConfigure controlfile autobackup on;Configure controlfile autobackup off; Method 2: Use user-managed backupAlter database backup controlfile to