Progress
DataServer
for ODBC Guide
Data Source Record Locking
In a DataServer application, an ODBC data source handles all of its own locking issues. The Progress 4GL locking rules do not apply when you access information from an ODBC data source.
Table 2–7 provides data-source-specific comparisons.
Each data source uses locks or optimistic concurrency control automatically to isolate users from each other in a multi-user configuration. Your data source and ODBC driver may provide one or a number of transaction isolation levels. In a multi-user configuration, you can isolate users from each other in your data source by setting the isolation level (if the ODBC driver permits). In your Progress schema holder, use the -Dsrv TXN_ISOLATION,n connection parameter (where n = 1, 2, 4, or 8) to set the isolation level in ODBC. See the Microsoft ODBC Programmer’s Reference for more information and the reference manuals provided by your data source vendor for supported isolation levels.
NOTE: Certain earlier versions of DB2, Sybase, and Microsoft SQL Server 6.5 use page-level locking rather than record-level locking. This can affect data access when two or more users attempt to read or update different records that are on the same page. See your data-source documentation for details.
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