Database Administrator

New Features of MySQL5.6 Multi-Range Read 1. IntroductionMySQL 5.6 provides many performance optimization features, one of which is Multi-Range Read (MRR). It is used for queries based on secondary/secondary indexes, reduce random IO and convert

170th questions, 053170170. ASM supports all but which of the following file types? (Choose all that apply .)A. Database filesB. SpfilesC. Redo-log filesD. Archived log filesE. RMAN backup setsF. Password filesG. init. ora filesAnswer:FG Files

[Translated from mos] OS hang, [Translated from mos] OS hang when dbua is upgraded to around 70% Source: Database Upgrade Crashes Server at around 70 Percent (Document ID 551886.1) Applicable:Oracle Server-Enterprise Edition-Version: 10.2.0.2Linux x8

Advanced mongodb 1 advanced query and advanced mongodb Query In the previous article, we talked about the basic operation http://blog.csdn.net/stronglyh/article/details/46812579 of mongodb crud. In this article, we will talk about advanced mongodb --

When creating a table in an Oracle 11.2 database, the RESULT_CACHE (mode default) ORA-00922: missing or invalid option, invaliddefault The RESULT_CACHE (mode default) ORA-00922: missing or invalid option was encountered when creating tables in

Getting started with mongodb I wrote how to install: http://blog.csdn.net/stronglyh/article/details/46805373 This article introduces mongodb First, check whether the service has been opened. There are two ways to open the service. The first is to

The simplest deployment method of Mysql replication environment, mysql environment deploymentThe simplest deployment method for the replication Environment The environment is as follows: Master has not been writtenMaster and Slave are in

The conditional record set is met in the Linq query. Query a dataset that meets the conditions in a able data set through linq 1. First define the variables of the query field, such as depth String strDepth = query depth value; Var dataRows = from

SQL Server and Oracle query results from multi-row records (datasets) and concatenate a string of SQL statements (vertical table data into spliced text), sqlserveroracle Scenario: For example, you need to query all student numbers whose scores are

View the databases and collections created by sedna, documents, and so on. In the installation directory of sedna, check the cfg directory: [xuzhina @ localhost sedna] $ ls export books_cfg.xml [xuzhina @ localhost sedna] $ ls data/books_files

MySQL (21) ------------ cache parameter optimization, mysql ------------ Databases are IO-intensive applications. Their primary responsibilities are data management and storage. We know that the time for reading a database from the memory is

Be alert to InnoDB and MyISAM Create Hash index traps, innodbmyisamMySql common storage engines InnoDB and MyISAM do not support Hash indexes. Their default indexes are B-Tree. However, if you define the index type as Hash when creating the index,

MySQL (20) ----------- database backup and restoration, mysql ----------- Data backup: Back up data using the mysqldump command The mysqldump command backs up data in the database into a text file. Table results and data in the table are stored in

MongoDB CRUD operations (focus on update operations) (1), mongodbcrudI. Introduction MongoDB is a high-performance, open-source, and non-pattern document-based database. It is currently the most popular NoSQL database product. Data is stored in a

Mysql/Java server support for emoji, mysqlemojiPreface: Recently developed iOS projects require the storage of user text, and naturally encounter the problem of how emojis such as emoji are supported by mysql DB. After several days, the switch and

Vs mysql connection error solution, vsmysql SolutionVs mysql connection error Solution First, configure the following steps: **-(1) Open the Options Option Under the Tools menu of the VC6.0 toolbar, and select "program defiles" from the "Show

Install MongoDB and kylin15.05mongodb on Ubuntu Kylin15.05Install MongoDB on Ubuntu Kylin15.05 MongoDB is a typical NoSQL, but it is also said that many people are using it. So I tried to install the database on Ubuntu Kylin. First, go to its

MySQL (17) ----------- Query Optimization for massive databases, mysql ----------- Many Programmers think that query optimization is a task of DBMS (Database tutorial Management System). It has little to do with the SQL statements compiled by the

The Device \ Harddisk1 \ DR1 has an incorrect block, harddisk1dr1 Recently I encountered a problem with the Oracle DB system tablespace on windows. The first reaction was to view the windows Log Viewer. An error was indeed found:The Device \

Mysql syntax, special symbols, and regular expressionsHttp://blog.csdn.net/pipisorry/article/details/46773545 Common Mysql display commands 1. display the list of databases on the current database server: Mysql>Show databases; Note: the mysql