VARCHAR Type and MSSQL Database Connection Property

VARCHAR Type Column in Database

Note Version specific: 3.81.10 

For MSSQL Users that have VARCHAR type columns in their MES Database, they may want to adjust their Ignition MSSQL Database Connection Property.

If the system detects an MSSQL VARCHAR column, and the Connection's sendStringParametersAsUnicode is not False, a warning will appear on module startup:

  • MSSQL MES Analysis Datasource connection property 'sendStringParametersAsUnicode' is true, but contains VARCHAR column (MESObjectLink.MESObjectType);this may lead to implicit NVARCHAR conversions which may cause performance degradation. Please set sendStringParametersAsUnicode=false (semicolon delimited) in the Extra Connection Properties in the Ignition Database Connection configuration page for (YourDatabaseConnection).

In the Extra Connection Properties Field (where the Database name is provided), the property can be added like so:

  • sendStringParametersAsUnicode=false

These changes will help to prevent some* Implicit NVARCHAR conversion warnings, which lead to performance degradations.

  • Most of our queries will not be affected by this connection property because a significant refactoring job will be required to adjust every single query in the software to avoid this conversion.
    • This topic aims to relieve some of the unwanted implicit conversions when drawing Track and Trace graph data.