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Extending HCL OneDB™Beyond standard relational database objects, HCL OneDB™ can be extended to handle specialized data types, access methods, routines, and other objects. HCL OneDB™ includes many built-in extensions that are fully integrated in the database server. HCL OneDB™ 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 HCL OneDB™.
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 HCL OneDB™ databases.
DataBlade® API Function ReferenceThe HCL OneDB™ DataBlade® API Function Reference describes the DataBlade® API functions and the subset of functions that the DataBlade® API supports.
Function descriptionsThis section gives comprehensive reference information about the functions that are valid within DataBlade® API modules. It lists the function descriptions in alphabetical order, with syntax, usage information, and return values for the functions.
The mi_hdr_status() functionThe mi_hdr_status() function returns the high-availability cluster replication status of the current server.

The mi_hdr_status() function

The mi_hdr_status() function returns the high-availability cluster replication status of the current server.

Syntax

    mi_integer mi_hdr_status(void)


Valid in client LIBMI application?	Valid in user-defined routine?
No	Yes

Usage

The mi_hdr_status() function returns information about:

the server type, such as primary server, SD secondary server, RS secondary server, or HDR secondary server,
HDR status,
the ability to update data on a secondary server (also known as proxy writes).

When C UDRs are executing as a part of SELECT, execute function, or execute procedure statements, they can call mi_hdr_status() to determine the mode of the current server.

The return value of mi_hdr_status() is of type mi_integer, which is interpreted as a bitmap. The meaning of each bit is defined in the milib.h file.

For more information about High-Availability Data Replication and high-availability cluster environments, see the HCL OneDB™ Administrator's Guide.

Return values

MI_HDR_ON: The HDR environment is configured and is working.
MI_HDR_PRIMARY: The current server is a primary server.
MI_HDR_SECONDARY: This value indicates whether the server is any type of secondary server. Current® secondary server types include HDR, SD secondary, and RS secondary servers. This return code has been preserved for compatibility with earlier versions. The return code MI_SECONDARY has the same return code as MI_HDR_SECONDARY. Use MI_SECONDARY instead of MI_HDR_SECONDARY for new application development. Use MI_HDR_SEC_NODE to determine whether the server is an HDR secondary server.
MI_SECONDARY: The current server is a secondary server.
MI_HDR_SEC_NODE: The current server is an HDR secondary server.
MI_RSS_SECONDARY: The current server is an RS (Remote Standalone) secondary server.
MI_SDS_SECONDARY: The current server is an SD (Shared Disk) secondary server.
MI_UPDATABLE_SECONDARY: The current server is a secondary server that is configured to accept updates.