Home
Extending Informix®Beyond standard relational database objects, HCL Informix® can be extended to handle specialized data types, access methods, routines, and other objects. Informix® includes many built-in extensions that are fully integrated in the database server. Informix® also provides DataBlade® modules, which are packages of extended database objects for a particular purpose and that are installed separately from the database server. Alternatively, you can create your own user-defined objects for Informix®.
Creating extensionsYou can create user-defined data types, routines, access methods, and other database objects to suit your needs. You can use application programming interfaces to write user-defined routines and applications that access data in Informix® databases.
Virtual-Index Interface GuideThe Informix® Virtual-Index Interface Programmer's Guide explains how to create a secondary access method with the Virtual-Index Interface (VII) to extend the built-in indexing schemes of HCL Informix® typically with a DataBlade® module.
Develop an access methodThese topics describe the steps that you take to implement a user-defined access method with the Virtual-Index Interface (VII).
Testing the access methodTo test the access method, take the same actions that users of the access method take to create and access virtual data.
Create and specify storage spacesA storage space is a physical area where the table data is stored. To test how the access method builds new indexes, you create a new physical storage space before you create the index.
Storing virtual data in an extspaceAn extspace lies outside the disk storage that is configured for the database server. To create a physical extspace, you might use an operating system command or use a data management software system.

Storing virtual data in an extspace

An extspace lies outside the disk storage that is configured for the database server. To create a physical extspace, you might use an operating system command or use a data management software system.

About this task

An extspace can have a location other than a path or file name because the database server does not interpret the location. Only the access method uses the location information.

Important: The use of external storage for secondary access methods is discouraged because you must provide transaction integrity, rollback, and recovery for indexes that are in external storage spaces. If the access method requires external-space support, follow the guidelines in this section.

To store virtual data in an extspace, take one of the following actions:

Procedure

Create logical names for existing external storage with the onspaces utility. Then, specify the reserved name or names when you create a virtual index with the CREATE INDEX statement.
Directly specify an existing physical external storage location as a quoted string in the CREATE INDEX statement.
Provide a default physical external storage location, such as a disk file, in the access-method code.

Rate this topic

5 stars 4 stars 3 stars 2 stars 1 star

Comment on this topic.

By clicking this box, you acknowledge that you are NOT a U.S. Federal Government employee or agency, nor are you submitting information with respect to or on behalf of one. HCL provides software and services to U.S. Federal Government customers through its partners immixGroup, Inc. Contact this team at https://hcltechsw.com/resources/us-government-contact. Do not include any personal data in this Comment box.