reference index definition

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

This article is transferred from: Http://www.cnblogs.com/abcdwxc/archive/2007/12/11/990274.html ----------------------- Creates an index for a given table or view.Only the owner of a table or view can create an index for the table. The owner of a

The main considerations for designing SQL Server indexes are as follows:Check where condition and join condition column;Use narrow index;Check the selectivity of the column;Check the data type of the column;Consider the order of the columns;Consider

The main considerations for designing SQL Server indexes are as follows:Check where condition and join condition column;Use narrow index;Check the selectivity of the column;Check the data type of the column;Consider the order of the columns;Consider

MySQL 5-1 -- index bitsCN.com 1. MySQL has multiple rows that access tables. The most commonly used is sequential access and index access. Sequential access refers to browsing a table in one row, that is, full table scan. Disadvantage: it is very

MySQL common index, unique index, primary index, foreign key index, composite index, full-text index usage, mysql full-text index1. Common Index The only task of a common INDEX (INDEX defined by the KEY or INDEX keyword) is to speed up data access.

The concept of MySQL indexingAn index is a special kind of file (an index on a InnoDB data table is an integral part of a table space), and they contain reference pointers to all records in the datasheet. More generally, the database index is like a

This article mainly originates from the Internet mainstream article, just according to the individual understanding slightly makes the integration, behind has the reference link. I. Summary This paper takes the MySQL database as the research object

The main considerations for designing SQL Server indexes are as follows:Check where condition and join condition column;Use narrow index;Check the selectivity of the column;Check the data type of the column;Consider the order of the columns;Consider

Unique indexIf the primary key is not set to a clustered index when it is created, it must be a unique nonclustered index. In fact, the unique index, the name Incredibles, is that it requires the value on that column to be unique. A unique index