Understand
the benefits and limitations of ExpressConnect for Oracle (ECO) before deciding to migrate
from an older version of Replication Server using ECDA for Oracle to a newer Replication
Server using ECO.
The benefits of ECO over ECDA for Oracle are:
- ECO runs within the process space of Replication Server.
Unlike ECDA for Oracle, which operates independently from Replication Server
and can be located on a separate machine, ECO has no separate server process
that needs starting up, monitoring, or administering.
- Since Replication Server and ECO run within the same process,
no SSL is needed between them, and there is no requirement to configure
settings previously covered in the ECDA for Oracle global configuration
parameters.
- Server connectivity is derived from the tns_alias_name and oracle_sid_name provided to the Replication Server connection
create connection and alter connection commands. You need not
separately configure the equivalent to the ECDA for Oracle connect_string setting.
- You also need not configure the settings that are equivalent
to the ECDA for Oracle service-specific settings, such as text_chunksize, autocommit, and array_size. These settings are automatically determined by
Replication Server (in some cases based on the Replication Agent input) and
communicated to ECO.
The limitation of ECO is:
- Error messages emanating from the ECO itself are currently
available only in the us_english language in the iso_1 character set.
However, error messages emanating from Oracle are sent in the language and
character set that matches that of Replication Server.
- ECO
does not support the use of custom function strings that use large objects
(LOB).