StarQuest Data Replicator (SQDR) FAQs
Last Update: 14 March 2012
Product: StarQuest Data Replicator
Version: 3.75 or later
Article ID: SQV00DR006
This article answers frequently asked questions (FAQs) about the StarQuest Data Replicator (SQDR). For a general overview of SQDR and system requirements, see the SQDR product page.
StarQuest offers the separately licensed component, SQDR Plus, that provides incremental replication support for SQDR users. Incremental replication copies only the data that has changed, which reduces the amount of data that is transferred and allows the replication to occur more frequently. Incremental replication requires installing the SQDR Plus software on the host database system to monitor changes and communicate with the Data Replicator Windows-based service. SQDR Plus is currently supported on DB2 for i and DB2 UDB for Linux, UNIX & Windows systems.
If your source database is not DB2 and you wish to simulate incremental replication using SQDR, refer to the technique outlined in the StarQuest technical document Using SQDR for Limited Incremental Replication from SQL Server—Advanced.
If you attempt to create a subscription for a DB2 source table that contains a "." character in the table name, you may receive this error message:
[StarSQL][StarSQL ODBC Driver][DB2/400]Relational database <LIBRARY> not the same as the current server <DATABASE SERVER NAME>.
To replicate DB2 tables that contain a "." character in the table name, set the UseDSCRDBTBL configuration parameter to NO in the StarSQL data source configuration. This setting is accessible on the Experts Page panel of the data source configuration wizard. Restart the SQDR service to ensure that the new connection setting takes effect.
No, SQDR accesses host data through the ODBC interface, which supports most host data types and ranges of data values directly. When you configure a replication operation, SQDR queries the source database and automatically communicates data type and attribute information to the target database along with the actual data. You can also configure custom conversions for exceptional cases.
SQDR supports textual data in all national languages, including Double Byte Character Set (DBCS) languages. It relies on the ODBC interface, along with host and client code page configuration to ensure a transparent mapping between EBCDIC and ASCII (or Unicode) representations of the text.
Yes, you can choose to skip certain rows or columns of the source table, and you can also specify computed columns based on other columns in the source data. These specifications can be made by using the built-in replication options or by using SQL (structured query language) during the replication configuration process.
SQDR fully supports your host's data access security. It accesses host data through an ODBC data source, and each data source is configured with a host user name and password. The host database administrator manages the access rights for this account to the host database, so SQDR can only perform operations on the database that are permitted by the host account.
Yes, SQDR can replicate LOB data to and from DB2, SQL Server, and Oracle data sources.
SQDR will cache subscription information in memory to improve performance. It updates the information about the subscription when the SQDR service is stopped and restarted. It will also obtain the latest subscription information if the subscription properties have been changed. Add the subCacheLimit registry entry to the SQDR service registry key so that SQDR always retrieves new subscription information.
WARNING: If you use Registry Editor incorrectly, you may cause serious problems that could require you to reinstall your operating system. Edit the registry at your own risk.
1. Open the Windows Registry Editor (regedit.exe).
2. Locate the key: HKEY_LOCAL_MACHINE\SOFTWARE\StarQuest\SQDRSVC.
3. Add a new String Value called "subCacheLimit" and set this value to -1.
Entry Name: subCacheLimit
4. Close the Registry Editor and stop and restart the Data Replicator service.
The Data Replicator requires a control database in which to store definitions for sources, destinations, and subscriptions. You can use any of the following editions of SQL Server for the SQDR control database.
SQL Server 2012 or SQL Server 2012 Express
SQL Server 2008 or SQL Server 2008 Express
SQL Server 2005 or SQL Server 2005 Express Edition
SQL Server 2000 Desktop Engine (MSDE 2000) Release A, or MSDE 2000 SP3a or SP4
SQL Server 2000 with SP3a or SP4
If you do not already have a SQL Server installation, you can obtain the MSDE 2000, SQL Server 2005 Express Edition, SQL Server 2008 Express or SQL Server 2012 Express free of charge from Microsoft. Refer to the StarQuest technical document "Installing SQL Server for a Control Database" for more information about using these versions of SQL Server as a control database for the Data Replicator.