Used in the context of HCL®
OneDB® database
servers, the term heterogeneous environment is a group of database
servers in which at least one of the database servers is a different
database server. Heterogeneous commit ensures the all-or-nothing basis
of distributed transactions in a heterogeneous environment.
Unlike the two-phase commit protocol, the heterogeneous commit
protocol supports the participation of a participant that is not HCL
OneDB. The
other participant, called a gateway participant, must communicate
with the coordinator through the HCL
OneDB gateway.
The database server uses heterogeneous commit protocol when the
following criteria are met:
Heterogeneous commit is enabled. (That is, the HETERO_COMMIT configuration
parameter is set to 1.)
The coordinator of the commit is a version
7.2 or later HCL
OneDB.
The gateway participant communicates with the HCL
OneDB database
server through the HCL
OneDB gateway.
At most, one gateway participant performs an update within a single
transaction.
The following figure illustrates this scenario.Figure 1: Configuration that requires heterogeneous
commit for distributed transactions
