index command in sql

MySQL index details, MySQL index detailsI. Introduction to index basics 1.1 In MySQL, indexes are also called keys. They are a data structure that the storage engine uses to quickly find records. Indexes are critical to good performance. Especially

In the database, the index is a special object, it is a database structure that can speed up the data retrieval, it can quickly find the necessary content from the large amount of data, make the data query without retrieving the whole database. An

SYS. dm_exec_requests is a powerful tool to check the performance bottleneck of SQL Server. Update statistics t_goods with fullscan --- Update table statisticsThe index leaves of clustered indexes are the data itself.The leaf node of the

    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

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

http://blog.csdn.net/tianlesoftware/article/details/5347098 A Index Introduction 1.1 Creation syntax for indexes: CREATE UNIUQE | BITMAP INDEX . On . ( | ASC | DESC, | ASC | DESC,...)Tablespace STORAGE LOGGING | NologgingCOMPUTE

A Index Introduction1.1 Creation syntax of the index:CREATE UNIUQE | BITMAP INDEX .On .( | ASC | DESC, | ASC | DESC,...)Tablespace STORAGE LOGGING | NologgingCOMPUTE STATISTICSnocompress | CompressNosort | REVERSEPARTITION | GLOBAL

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

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

Definition: 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. For example such a query: SELECT * FROM table1 where id=10000. If