Virtuoso allows incremental and bi-directional snapshot replication flavors to be used with non-Virtuoso databases.

The following databases are supported in incremental snapshot replication:

SQL Server 2000 and later
Oracle 8i and later
IBM DB2 8.1 and later
Informix IDS 9.40 and later

The following databases are supported in bi-directional snapshot replication:

SQL Server 2000 and later
Oracle 8i and later
IBM DB2 8.1 and later

DBMS-specific notes:

  1. SQL Server 2000 and later Bi-directional snapshot triggers for SQL Server require "nested triggers" server option to be "On" (which is "On" by default).

  2. Oracle 8i

    1. Oracle 8i does not have support for "localtimestamp" data type out of box. Required functionality can be enabled by editing $ORACLE_HOME/rdbms/admin/standard.sql script. The following statement

      pragma new_names('8.1.6',
                       dbtimezone, sessiontimezone, localtimestamp,
                       localtime, to_local_tz, to_db_tz,
                       cube, rollup, grouping, "TIMESTAMP WITH LOCAL TIME ZONE");
      

      should be changed to

      --pragma new_names('8.1.6',
      --                 dbtimezone, sessiontimezone, localtimestamp,
      --                 localtime, to_local_tz, to_db_tz,
      --                 cube, rollup, grouping, "TIMESTAMP WITH LOCAL TIME ZONE");
      

      After $ORACLE_HOME/rdbms/admin/standard.sql is edited it should be executed with SYS user privileges:

      $sqlplus SYS/CHANGE_ON_INSTALL @$ORACLE_HOME/rdbms/admin/standard.sql
      

      where "CHANGE_ON_INSTALL" is password for user SYS.Oracle 9i and later has this type in the default installation and this step is not necessary.

    2. ODBC driver from Oracle 8.1.6 (and earlier versions) is known to be buggy and may cause Virtuoso server to crash when snapshot replication with Oracle database is set up. ODBC driver from Oracle 8.1.7 and later is recommended.

    3. Oracle ODBC driver uses Oracle NLS settings by default for determining decimal separator. If decimal separator in the locale is not '.' (period) there will be interoperability errors with Virtuoso. Oracle ODBC driver can be forced to use US Settings for numerics: open Oracle ODBC driver configuration dialog, select "Application" tab and set "Numeric Settings" to "Use US Settings".

  3. DB2 8.1 ESE

    1. FixPak 3 is recommended because ODBC driver from earlier DB2 8 versions may cause Virtuoso server to crash when BLOB columns exist in replicated tables.

    2. DB2 CLI/ODBC driver uses default locale's decimal separator. If decimal separator in the locale is not '.' (period) Virtuoso fails to parse numeric values. The default behavior of the DB2 CLI/ODBC driver can be modified by specifying PATCH2 CLI/ODBC configuration keyword in the db2cli.ini initialization file. Add the following line to your DSN config in db2cli.ini:

      PATCH2=15
      

      This will force DB2 CLI/ODBC driver to always use period ('.') as decimal separator.

  4. Informix IDS 9.40 Informix IDS can't report current time in UTC. This may cause snapshot replication to fail when timezone change occurs. In order to set up snapshot replication with Informix server properly any of the following steps must be taken:

    Informix server must be run in UTC time zone.
    "snp_repl_time_offset" registry variable should be set to value greater than 60.

    The second method may cause additional system load on updates and will cause transactions to be replayed out of order when timezone change occurs.