Indexes
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Indexes are optional structures associated with tables. You can create indexes specifically to speed SQL statement execution on a table. When properly used, Indexes are the primary means of reducing disk I/O. Indexes are logically and physically independent of the data in the associated table. Unique Indexes guarantee that no two rows of a table have duplicate values in the columns that define the index.
Contents
Creating and editing
- Indexes Wizard (DB2 LUW) and Indexes Editor (IBM DB2 LUW)
- Indexes Wizard (DB2 Z/OS) and Indexes Editor (IBM DB2 Z/OS)
- Indexes, Primary Keys, or Unique Keys wizard (MySQL) and Indexes, Primary Keys, and Unique Keys editors (MySQL)
- Indexes Wizard (Oracle) and Indexes Editor (Oracle)
- Indexes Wizard (PostgreSQL) and Indexes Editor (PostgreSQL)
- Indexes Wizard (SQL Server) and Indexes Editor (SQL Server)
- Indexes Wizard (Sybase ASE) and Indexes Editor (Sybase ASE)
- Note: Creation and editing of objects of this type is not supported against Sybase IQ datasources.
DBMS platform availability and object actions/operations supported
The following table lists object actions available for this object type. For an introduction to object actions and details on usage of specific actions, see Object actions.
| DB2 LUW | DB2 z/OS | MySQL | ORCL | PSTGRS * | SQL SVR | SYB ASE | SYB IQ | SYB IQ | |
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Missing Indexes
Missing indexes is a feature which helps you to improve the performance of your system. The Missing indexes functionality proposes you to create new indexes for improving the system in case they are needed.
Availability of Missing Indexes for different DBMS: