Database Administrator

Use YCSB to test MongoDB's performance MongoDB database-Level Lock MongoDB is currently the most popular NoSQL database. It is favored by many developers with its natural document-type data structure, flexible data models, and easy-to-use horizontal

Node. js remotely connects to the MongoDB database server on another host My MongoDB is installed in linux. First, add a user 1. First, run the terminal command line on the MongoDB server host and enter Mongo 2. Enter use admin to access the user

MySQL database Constraints Database constraints:A constraint is a data validation rule enforced on a table. It is mainly used to ensure data integrity in the database.In addition, when the data in the table is mutually dependent, the related data is

Oracle Materialized View Details In actual work, multiple data sources are synchronized to a single database for data analysis. These data can not be synchronized in real time. Generally, we extract data from the statistical analysis database

What if MySQL transactions contain DDL statements? As we all know, MySQL DDL statements are non-transactional, that is, DLL statements cannot be rolled back. What if a transaction contains DDL statements? For example: # Disable automatic

Red Hat Enterprise Linux AS4, C ++ OCCI connect Oracle 9i Red Hat Enterprise Linux AS4, C ++ OCCI connect Oracle 9i, provided that Oracle 9i has been installed. 1. Download the corresponding ORACLE client

CentOS 7.0 use yum to install simple configuration of MariaDB and MariaDB I forgot about the environment configuration of the space that has been idle for a long time. I have to leave it empty today and reset the disk to re-build the environment.

Directory I. Overview Ii. Hardware Platform Construction Iii. RedHat As4 update2 installation Configuration Iv. Oracle 10 Gb installation and configuration V. Red Hat Cluster Suite installation and configuration 6. system switching test VII. Common

Solve the problem that inventory is reduced to negative in the case of concurrency, and the inventory is negative. Scenario: If a commodity is in stock, check the inventory before placing the order. If it is greater than 0, place inventory-1 and

Oracle uses a single cursor to insert data. For example, oracle cursor Original works, from "Deep Blue blog" blog, deep blue blog: http://blog.csdn.net/huangyanlong/article/details/47143731Background Recently, some friends asked me how to insert

MySql basic query, connection query, subquery, regular expression query explanation, mysql explanation Original works of Lin bingwen Evankaka. Reprinted please indicate the source http://blog.csdn.net/evankaka Querying data refers to obtaining the

Question: In my daily work, I think MySQL plus is used in 99% to log on to the database and manage, optimize, and configure the database. If there are many databases, all of them are unified SQL after connection>, it may happen that we do not know

New Features of Oracle DB 12c: raw device bare devices are no longer supported, oracle12c New Feature of Oracle DB 12c: raw device is no longer supported. Reference:Announcement of De-Support of using RAW devices in Oracle Database Version 12.1 (Doc

Oracle learning path (2) ------ use of array type/record type, oracle ------Oracle record types RECORD: A composite data type consisting of scalar values in multiple columns of a single row, it encapsulates one or more scalar values into one object

Describes the range type features and PostgreSQL features in postgresql. A new feature of PostgreSQL 9.2 is the range type range types. With this name, you can easily guess the purpose of this type. It allows you to define a value range for a column

Judging the total number of records in a table is the most common thing for a developer. I think the common practice is: Select count (*) from table name; This is not done. I am mainly talking about efficiency issues here. When the number of

DDL Wait options JillAcme Retailers DBA) tries to change the table named SALES and add a column of TAX_CODE to it. This is a common task; she executes the following SQL statement: SQL> alter table sales add (tax_code varchar2(10));

Using script files to manage Oracle databases has great advantages. For example, you can reduce the command input. For example, you can save the commands that pass the debugging test so that you can use them again when needed. For example, you can

I SELECT a table in a production test database when a ORA-01578, a block damage, previously learned how to deal with block damage, to really have not met, today finally let me met, it's still a production test database, so you don't have to be

With the increasing popularity of information technology, the informatization of small and medium-sized enterprises is also in full swing! However, most SMEs encounter a lot of confusions when deploying IT systems: lack of professional technical