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SQL programmingYou can use the HCL OneDB™ implementation of the SQL language to develop applications for HCL OneDB™ database servers.
Guide to SQL: ReferenceThe HCL OneDB™ Guide to SQL: Reference contains the reference information for the system catalog tables, data types, and environment variables of the HCL OneDB™ dialect of the SQL language, as implemented in HCL OneDB™. These topics also include information about the stores_demo, sales_demo, and superstore_demo databases that are included with HCL OneDB™.
Environment variablesVarious environment variables affect the functionality of your HCL OneDB™ products. You can set environment variables that identify your terminal, specify the location of your software and define other parameters.
Environment variables in HCL OneDB™ productsThe topics that follow discuss (in alphabetic order) environment variables that HCL OneDB™ database server products and their utilities use.
OPTMSG environment variable

OPTMSG environment variable

Set the OPTMSG environment variable at runtime before you start the application to enable (or disable) optimized message transfers (message chaining) for all SQL statements in the application.

0: disables optimized message transfers.
1: enables optimized message transfers and implements the feature for any subsequent connection.

The default value is 0 (zero), which explicitly disables message chaining. You might want, for example, to disable optimized message transfers for statements that require immediate replies, for debugging, or to ensure that the database server processes all messages before the application terminates.

When you set OPTMSG within an application, you can activate or deactivate optimized message transfers for each connection or within each thread. To enable optimized message transfers, you must set OPTMSG before you establish a connection.

For more information about setting OPTMSG and defining related global variables, see the HCL OneDB™ ESQL/C Programmer's Manual.