Estimating Index Pages for Spatial and User-Defined Data

The database server uses the following types of indexes:

• B-tree
• R-tree
• Indexes that DataBlade modules provide

B-Tree Indexes

Dynamic Server uses a B-tree index for the following values:

• Columns that contain built-in data types (referred to as a traditional B-tree index)

  Built-in data types include character, datetime, integer, float, and so forth. For more information on built-in data types, see IBM Informix: Guide to SQL Reference.

• Columns that contain one-dimensional user-defined data types (referred to as a generic B-tree index)

  User-defined data types include opaque and distinct data types. For more information on user-defined data types, see IBM Informix: User-Defined Routines and Data Types Developer's Guide.

• Values that a user-defined function returns (referred to as a functional index)

  The return value can be a built-in or user-defined data type but not a simple large object (TEXT or BYTE data type) or a smart large object (BLOB or CLOB data type). For more information on how to use functional indexes, see Using a Functional Index.

For information about how to estimate B-tree index size, see Estimating Index Pages.

R-Tree Indexes

Dynamic Server uses an R-tree index for spatial data (two-dimensional, three-dimensional, and so forth). For information about sizing an R-tree index, see the IBM Informix: R-Tree Index User's Guide.

Indexes That DataBlade Modules Provide

In Dynamic Server, users can access user-defined data types that DataBlade modules provide. A DataBlade module can also provide a user-defined index for the new data type. For example, the Excalibur Text Search Datablade provides an index to search text data. For more information, see the IBM Informix: Excalibur Text Search DataBlade Module User's Guide.

For more information on the types of data and functions that each DataBlade module provides, see the user guide of each DataBlade module. For information on how to determine the types of indexes available in your database, see Determining the Available Access Methods.