Logging-type restrictions on distributed queries

To execute distributed queries in the HCL® OneDB® database server environment, all participating databases must be of compatible transaction-logging types:

• Distributed queries are supported on an ANSI-compliant database only if all of the participating databases are also ANSI-compliant.
• Distributed queries on a database that does not support transaction logging are supported only if all of the participating databases also do not use transaction logging.
• Distributed queries on a database that is not ANSI-compliant but that uses explicit transaction logging are supported if all of the other databases also use explicit transaction logging.

In the last case, whether a participating database uses buffered or unbuffered logging does not affect its ability to support distributed operations. In the X/Open distributed transaction processing (DTP) environment, all databases must use unbuffered logging. See the HCL OneDB Administrator's Guide for more information about database logging types and X/Open DTP.