how to improve query performance

MySQL optimized debug command1, mysqld--verbose--helpThis command generates a list of all mysqld options and configurable variables2. By connecting to it and executing this command, you can see the value of the variable actually used:Mysql> show

As we all know, as long as the rational and correct use of PDO, can basically prevent the production of SQL injection, this article mainly answers the following two questions: Why use PDO instead of mysql_connect? Why PDO can prevent injection?

caching-type Web application architecture: A cache layer is added between the web layer and DB layer, the main purpose is to reduce the load of database reading and improve the speed of data reading. Cache access is the medium of memory, you can

Original address: http://hi.baidu.com/gukeming888/blog/item/2682f69481c8237154fb9662.html Materialized views (materialized view), referred to as snapshots (Snapshot) in previous versions of Oracle. The materialized views of Oracle provide powerful

Ext: http://blog.csdn.net/pang040328/article/details/4164874 Why do you want to create an index? This is because creating an index can greatly improve the performance of the system.First, you can guarantee the uniqueness of each row of data in a

what is an index. Indexes are used to quickly look for records with a specific value, and all MySQL indexes are saved as a B-tree. Without an index, MySQL must begin scanning all records of the entire table from the first record until a record is

Introduction of Oracle Partition Oracle partitioning is a technique for handling oversized tables, indexes, and so on. Partitioning is a "divide and conquer" technique that provides scalable performance for large amounts of data by dividing large

In the previous article, I introduced several forms of the classification of the library and play, but also focused on the vertical library brought about by the problems and solutions. In this article, we will continue to talk about some of the

This article from the following aspects to collate the concept and operation of the partition table:1. Table space and the concept of partitioned tables2. The specific role of table partitioning3. Advantages and disadvantages of table partitioning4.

Oracle Partition Partition Detailed summary This article from the following aspects to collate the concept and operation of the partition table:         1. Table space and the concept of partitioned tables         2. Table partitioning specific

Create materialized view [view_name]Refresh [Fast|complete|force][On [Commit|demand] |Start with (start_time) next (next_time)]As{Create a query statement for materialized views} These are the common syntax for Oracle to create materialized views (

Why do you want to create an index? This is because creating an index can greatly improve the performance of the system. First, you can guarantee the uniqueness of each row of data in a database table by creating a unique index. Second, you can

Server|web| Program | full-Text Search Build a WEB Search application using Microsoft SQL Server 2000 Full-text search capabilities Andrew B. Cencinimicrosoft Corporation December 2002 applies To: &N Bsp Microsoft®sql™server 2000 Summary: Learn how

oracle| Object | data | Database integrity constraints Integrity constraints are used to enhance data integrity, Oracle provides 5 kinds of integrity constraints: Check Not NULL Unique Primary Foreign Key Integrity constraints are a rule that

This article discusses the types of indexes that MySQL supports and their pros and cons. Note that in MySQL, indexes are implemented at the storage engine level rather than the server layer, so the indexes of the different storage engines work

Brief introduction In SQL Server, an index is an enhanced existence, which means that SQL Server can still implement functionality even without indexes. However, indexes can greatly improve query performance in most cases, especially in OLAP. To

Statistics Canada (Statistics Canada) is a federal government agency in Canada, which is responsible for censuses and calculations, which, every five years, carries out a census of 27 million people in Canada and provides results to government

Version 1.2 [2006-11-12] Brief introduction This tutorial, on the basis of the previous article "NBearV3 Step through step tutorial--orm", demonstrates the entity autocorrelation relationships that are not covered in the previous article;

Oracle 11g on July 11, 2007 11 O'Clock (Beijing time 11th 22 o'clock) officially released, 11g is Oracle 30 years to release the most important version of the database, according to the needs of users to achieve information lifecycle management

Server The first thing to note is that the content of this article is not how to adjust SQL Server query performance (to write a book about this), but how to use set STATISTICS IO and set STATISTICS in the tuning of SQL Server query performance Time