db cursor [-txn txnid]
The db cursor command creates a database cursor. The returned cursor handle is bound to a Tcl command of the form dbN.cX, where X is an integer starting at 0 (for example, db0.c0 and db0.c1). It is through this Tcl command that the script accesses the cursor methods.
The options are as follows:
-txn txnid
If the operation is part of an application-specified transaction, the txnid parameter is a transaction handle returned from env txn. If no transaction handle is specified, but the operation occurs in a transactional database, the operation will be implicitly transaction protected.
In the case of error, a Tcl error is thrown.