Database Administrator

Redis database (list type) List is a linked list structure. The main function is to push, pop, get all values in a range, etc. In the operation, the key can be understood as the name of the linked list. In Redis, the list type is actually a

CentOS 6.3 Environment Oracle 11gR2 Database Installation CentOS 6.3 Environment Oracle 11gR2 Database Installation 1. install necessary OS installation packages We recommend that you install the operating system to the maximum extent, because the

Oracle continuous data processing example The function described in the following section is to have a table in the Oracle database, which stores continuous time records and a tag bit. Now you need to obtain a result set: when the flag bit is 0, the

Mysql foreign key Usage introduction, mysqlforeign I. Basic Concepts 1. MySQL has the same definition of "key" and "Index", so foreign keys and primary keys are also an index. The difference is that MySQL will automatically index the primary keys of

Problems with data import in different mysql versions: mysql version Data Import The original mysql version is 3.4.10.1deb1, and the target mysql version is 5.0.51b-community-nt-log. The following error occurs during data import: 1. DELIMITER You

The bug that the change execution sequence caused by the common table expression (CTE) is the same as that caused by the WHERE condition order, ctewhereThe following simulated CTE Error /* Test environment Microsoft SQL Server 2008 R2 (RTM)-10.50.16

Database Transaction introduction and instance, Database Transaction instance What is a database transaction?Database transactions are a series of operations performed as a single logical unit of work. Specifically, Several SQL statements can be

Install mysql-proxy and centosmysql-proxy on centos Mysql-proxy is useless. mysql-proxy depends on libevent, lua, glib2, and other software. So before installation Yum install lua-develyum install glib2-devel Libevent I use source code to

Database Optimization-horizontal segmentation-and Application in actual projects, splitting projects Horizontal database partitioning, relatively vertical partitioning, requires more work and tasks, but it is necessary for tables with a particularly

Explore Redis data expiration policies and redis strategies Use the EXPIRE key seconds command to set the data expiration time. If the return value is 1, the setting is successful. If the return value is 0, the key does not exist or the expiration

The image cannot be displayed in the Oracle12cR1 official document, After downloading the official Oracle12cR1 documents, some images cannot be displayed on the homepage, as shown below: Solution: Under the E50529_01 \ dcommon \ js \ directory,

Oracle Performance Optimization Operation 7: Index improves query efficiency when data distribution is uneven, and oracle Performance Optimization Index selection is low, but the data value distribution is very different, you can still use the index

Summary of SQL statements for Oracle row-to-column and column-to-row, oraclesql Reference: Functions | or concat functions can be implemented. select concat(id,username) str from app_userselect id||username str from app_userConverting strings to

Measure object size function performance comparison and object function performance comparison gtgpdb=# select * from gp_toolkit.gp_size_of_table_disk t where sotdtablename like 'rt_ok%'; sotdoid | sotdsize | sotdtoastsize | sotdadditionalsize |

T-SQL cursor, t-SQL Ø cursorA cursor can process a select result set or return a result after processing the record set.Create PROCEDURE [dbo]. [region] @ DevName varchar (2000), @ starttime varchar (200) asbeginset nocount on; -- Set @ DevName =

Check whether the foreign key column is the two statements of the index column. This article is taken from page 37th and page 38th of oracle index technology.   Check whether the foreign key column is one of the index column statements: select

MySQL self-study (10) -- date functions and mysql self-study date functionsDate and Time Functions (1) functions for obtaining the current date and time CURDATE () and CURRENT_DATE () functions to obtain the current date Select current_date (),

The unique identifier (ID) of the database. Background: In years of work, we have designed many system or product databases, including single-host databases, lan databases, and Internet databases. For different environments, the design

The importance of manual collection of statistical information after filling in a large amount of data 1. Create a test table TBL_STAT and an index without inserting records. SQL> create table TBL_STAT as select * from dba_objects where 1 <>

Seven service descriptions for oracle11g and oracle11g A total of 7 services have been installed at oracle11g. 1. oracle orcl vss Writer Service: Oracle Volume ing Copy write Service. VSS (Volume Shadow Copy Service) allows storage basic devices