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-Table Interface GuideThe Informix® Virtual-Table Interface Programmer's Guide explains how to create a primary access method with the Virtual-Table Interface (VTI) so that users have a single SQL interface to HCL Informix® tables and to data that does not conform to the storage scheme of HCL Informix®.
Design decisionsThese topics present the choices that you make to optimize the performance and flexibility of the access method that you can create with the virtual-table interface (VTI).
Supply error messages and a user guide
Avoid database server exceptions
Keywords that the access method does not supportYou must set a purpose flag to indicate the existence of code within the access method to support certain keywords. If a purpose flag is not set, the database server assumes that the access method does not support the corresponding keyword and issues an error if an SQL statement specifies that keyword.

Keywords that the access method does not support

You must set a purpose flag to indicate the existence of code within the access method to support certain keywords. If a purpose flag is not set, the database server assumes that the access method does not support the corresponding keyword and issues an error if an SQL statement specifies that keyword.

For example, unless the am_cluster purpose flag is set in the sysams system catalog table, an SQL statement with the CLUSTER keyword fails. If the access method does not provide for clustering, the access-method user guide must advise users not to use the CLUSTER keyword.

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.