Database Administrator

MySQL File Sorting & Index sorting, mysql File Sorting Sorting is a very cpu-consuming operation. When the system is improperly set or the query retrieves too many fields, MySQL may have to discard the optimized sorting algorithm, however, the old

Study database notes 6. Database notes I Summarized some problem-solving templates, which can be applied in some cases Model 1 group by + statistical function combinationExampleCalculate the number of items under each topicSelct cat_id, count (*)

Authorization for CONNECT, RESOURCE, and DBA in ORACLE, oracledba CONNECT, RESOURCE, and DBA are the three built-in roles of the ORACLE system. The role permissions are as follows: CONNECT: users with the Connect permission can only log on to

Study database notes 5. Database notes I Where subquery The inner query result acts as the outer query condition. 1. query the latest product Step a) select max (goods_id) from goods; this is a dynamic statement, and how to add it will be

Basic database architecture and log functions, database architecture logs1. Why mysql? MySQL features a plug-in storage engine to facilitate read/write splitting It is open-source and free2. How database software runs in the Early Stage: data is

[Translated from mos] nodes are not displayed in the "Cluster Node Information" or "Specify Cluster Configuration" window on aix and the add button is gray. nodecluster Nodes are not displayed in the "Cluster Node Information" or "Specify Cluster

DataTable add data, datatable add DataTable dt = new DataTable ("cart "); DataColumn dc1 = new DataColumn ("prizename", Type. GetType ("System. String ")); DataColumn dc2 = new DataColumn ("point", Type. GetType ("System. Int16 ")); DataColumn

Article Title multi-Table query: merged result set, connection query, subquery, and article title merge Multi-Table queryCategory:* Merge result sets* Connection Query* Subquery[1] merge result sets * The number of columns in the table to be merged

Message interaction process between C language programs and databases in non-direct connection mode, and language program process Abstr] In "how to execute SQL statements in C language?" (Http://www.zhouzhaoxiong.com/116.html) in the article, I

9 Key Points for optimizing Redis memory9 Key Points for optimizing Redis memory  1. Pay attention to the special encoding settings for small aggregate data types in redis. conf:   Hash-max-zipmap-entries 64 (hash-max-ziplist-entries for Redis >=2.6)

Install GoldenGate Director, goldengatedireOracle GoldenGate Director is a multi-tiered client-server application that enablesConfiguration and management of Oracle GoldenGate instances from a remote client. Oracle GoldenGate Director consists of

SQL Server set function COUNT optimization analysis, sqlservercount Current version: Microsoft SQL Server 2008 R2 (RTM)-10.50.1600.1 (Intel X86) Apr 2 2010 15:53:02 Copyright (c) Microsoft Corporation Enterprise Edition on Windows NT 5.2 (Build 379

Study database notes 7. Database notes Internal Connection Query The two tables are connected to one table using inner join, and then queried. When filtering the two tables, the on (where is the condition for querying a single table) is

Preliminary understanding of BI-SSIS and BI-SSIS In the previous article, I briefly introduced the overall framework of BI. In the next few articles, I will briefly explain some knowledge points. First, we will go to SSIS learning.1. What is

Group by and having clauses, and grouphaving clausesGroup by clauseIn some cases. You need to divide the rows in a table into multiple groups, and then use the group as a whole to obtain information about the reorganization, such as the number of

Basic SQL internal connection and external connection, basic SQL connection Some problems have been depressing for a long time. For example, why is there a connection between the left and right sides? If the foreign key is empty, the foreign key

Beauty of the process-elevator degree algorithm and elevator Scheduling Algorithm Recently, I want to study the elevator Scheduling Algorithm in detail, but it involves too much content and there is no time. Types of elevator

In the condition following oracle where | what does it mean? oraclewhere| Is the Connection Symbol behind the oracle where clause. There is also a concat function in Oracle that can connect two strings.Concat (a, B)What are the usage and functions

Explanation of database paradigm and explanation of database paradigm Database paradigm 1NF 2NF 3NF BCNF (example) The design paradigm (paradigm, database design paradigm, and database design paradigm) is a set of relational patterns at a certain

ServiceStack. Redis -- Redis client solution on. net, servicestack. redisServiceStack. Redis -- Redis client solution on. net  Source code and usage: Https://github.com/ServiceStack/ServiceStack.Redis  Example: