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Original: Http://mp.weixin.qq.com/s/cqIK5Bv1U0mT97C7EOxmnA distributed unique ID minimalist tutorialOne, the signature All business systems have the need to generate IDs, such as order IDs, product IDs, article IDs, and so on. This ID will be the

Every InnoDB table has a special index called the clustered index where the data for the rows are stored. If you are define a PRIMARY key on your table, the index of the PRIMARY key is the clustered index. Each InnoDB table has a specific index

In my conscience, I can't tell you not to use core Data. It's good, and it's getting better, and it's been understood by many other cocoa developers that it's important to have new people join your group or need someone to take over your

1. Use the Set NOCOUNT on option:By default, each time a SQL statement is executed, a message is sent from the server to the client to display the number of rows affected by the SQL statement. This information is rarely useful to clients. By turning

MySQL noun explanation/meaning mvcc (multiversion concurrency control) The MySQL InnoDB storage engine, which implements the Concurrency Control Protocol--MVCC (Multi-version Concurrency Control) based on multiple versions (note: Compared

Ext: http://segmentfault.com/a/1190000000363392 Editor's note: The article "I" refers to the original author.In my conscience, I can't tell you not to use core Data. It's good, and it's getting better, and it's been understood by many other cocoa

How to optimize SQL statements (full) and SQL statements High-performance SQL statements play a very important role in software operation. The following section will share the latest SQL statement optimization materials. First:Select the most

    I. Index Introduction 1.1 index creation Syntax: Create uniuqe | bitmap index . ON . (| ASC | DESC, | ASC | DESC ,...) TABLESPACE STORAGE LOGGING | NOLOGGING COMPUTE STATISTICS NOCOMPRESS | COMPRESS NOSORT | REVERSE PARTITION | global

Abstract: This article will introduce how to optimize the performance of the database system to process various queries as quickly as possible. The function of indexes in optimizing queries includes the principle of optimizing indexes. indexes are

  This article introduces the database index, and its advantages and disadvantages. The features and applications of MySQL indexes are described in detail. This article analyzes how to avoid MySQL unavailability, how to use explain to analyze query

ReprintedBytes IndexYou can use indexes to quickly access specific information in database tables. An index is a structure that sorts the values of one or more columns in a database table (for example, the last name (lname) column of the employee

  [Disclaimer: All Rights Reserved. You are welcome to reprint it. Do not use it for commercial purposes. Contact Email: feixiaoxing @ 163.com]   In mathematics, there are some data options. For example, there is a set of data: 1, 2, 3, and 4. Now

We must not only write SQL statements, but also write SQL statements with excellent performance. (1) select the most efficient table name sequence (only valid in the rule-based Optimizer ): The Oracle parser processes the table names in the from

(1) Select the most efficient table name sequence (valid only in the rule-based Optimizer ):The Oracle parser processes the table names in the from clause in the order from right to left. The table written in the from clause (basic table driving

We should not only write SQL statements, but also write SQL statements with excellent performance. The following sections will help the author learn, extract, and summarize some materials to share with you! (1) select the most efficient table name

Some people often talk about reading and writing BLOB fields. I have been writing something recently. I have made some comparisons on the data types and functions of common databases, and I have also written a lot of tests.Code, The following are

(1) simple integration with no associated database access:If you have several simple database query statements, you can integrate them into a single query (even if there is no relationship between them) (2) Delete duplicate records: The most

(1) select the most efficient table name sequence (only valid in the rule-based Optimizer): The Oracle parser processes the table names in the from clause in the order from right to left, the base table driving table written in the from clause will

Write efficient SQL statements and SQL statements (1) simple integration with no associated database access: If you have several simple database query statements, you can integrate them into a single query (even if there is no relationship between

/*** * Node doubly linked list entity class * * *@authoryangkj *@version * @sinceAugust 15, 2016*/ Public classNode {//doubly linked List-previous nodeNode Previous; //doubly linked List-current node objectObject obj; //doubly linked list-next