Custom connection properties used by the UNICOM Intelligence Relational MR Database CDSC
This topic describes the custom connection properties that are unique to the UNICOM Intelligence Relational MR Database (RDB) CDSC.
You can specify custom connection properties by adding the MR Init Custom or MR Custom connection property to the connection string. The format is:
MR [Init] Custom = "<property_name> = <value>(; <property_name> = <value>)*"
For example:
MR Init Custom = "MaxMultiCol = 0; TransactionMode = 0"
Use the MR Init Custom property when you connect using the UNICOM Intelligence OLE DB Provider, for example, in DM Query or in a data management (.dms) script. If you are passing connection properties to a RDB CDSC object that you have created programmatically, use the MR Custom property.
For a list of all the standard connection properties that are available to the RDB CDSC, see
Connection properties.
Properties
FavorMemory
Uses server-side cursors so that a single SQL Server connection can be re-used across multiple commands. This mode is slower, but uses less memory (and fewer SQL Server connections) as the number of concurrent commands increases. Use the CursorFetchRows custom property to set the number of rows to fetch. Increasing the number of rows might increase performance.
If the CursorFetchRows custom property is not included, the default value of 20 rows is used.
FavorSpeed
Uses default cursors, requiring a new connection for each command. This mode is considerably faster than the FavorMemory mode, but does use more memory. The FavorSpeed option also optimizes binding look-up by creating a look-up vector. This is the default setting.
MaxCommandsPerConnection
Specifies the maximum number of commands that will share a single case data connection. By default, all commands open for a project (one command or recordset is created for each active interview) share the same database connection. When interviewing, if there is a high number of concurrent interviews for an individual project, the write performance of database case data can be impacted due to contention on the database connection. To reduce contention on the database connection, use MaxCommandsPerConnection.
This property can be set in the connection string or in DPM. Based on load testing, the suggested property value is 30.
TransactionMode
A long value that determines whether the RDB CDSC uses transactions. A value of 1 specifies that the RDB CDSC wraps up all data manipulation statements executed during a single connection into a single transaction, which is always committed. In addition, when a single transaction is used, the IRowsetFastLoad SQL Server interfaces are used. A value of 0 specifies that the RDB CDSC will not use transactions.
The default is 0, given that the RDB2 DSC's primary usage scenario is for multi-user updates. A value of 1 should be used in when performing bulk transfers to the RDB DSC, for example, when the RDB DSC is an OutputDataSource in a Data Management script. Transactions are used only when transferring to VDATA.
See also: