This article is transferred from:
Http://www.cnblogs.com/abcdwxc/archive/2007/12/11/990274.html
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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
Transferred from http://talentluke.iteye.com/blog/1843868
Excerpt from http://book.51cto.com/art/200906/132406.htm
the pros and cons of 8.4.5 indexes and how to determine whether an index is needed
I believe readers know that indexing can greatly
Indexes can often greatly improve the efficiency of queries, and if there is no index, MongoDB must scan every file in the collection and select those records that meet the query criteria when reading the data. This scan full set of query efficiency
PrefaceBefore writing to MySQL on the table additions and deletions (query the most important), it feels like MySQL is almost finished, did not want to continue to learn the mentality, the reason may be due to other people's influence, think for
An index is a structure that sorts the values of one or more columns in a database table and uses an index to quickly access specific information in a database table.Depending on the capabilities of your database, you can create three indexes in the
Start from Create
By using the explicit CREATE INDEX command
As an implied object when creating a constraint
Implicit indexes created with constraintsAn implicit index is created when you add one of the following two constraints to
Simple introduction to MySQL's index typefirst, introduce the type of indexMySQL Common indexes are: Primary key index, unique index, normal index, full-text index, composite indexPRIMARY key (primary key index) ALTER TABLE ' table_name ' Add
0. The conceptual index of an 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. Like a book in front of the directory, can
Concept:A primary key (primary key) uniquely identifies a property or group of properties for a row in a table. A table can have only one primary key, but there may be multiple candidate indexes. Primary keys often form referential integrity
Article attribution: http://feiyan.info/16.html, I want to write to myself, but found this June summed up very detailed. Moved right over here.With regard to the benefits of MySQL indexing, if the correct design and use of the indexed MySQL is a
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