Jim, Sam,

According to the Help (Begin transaction) of VFP 5.0:

Transactions can be nested five levels deep. An error is generated if you attempt a sixth level of nesting.

When you modify records in a database that is part of a transaction, other users on the network do not have access (read or write) to the records until you end the transaction.

When other users on the network try to access records you have modified, they must wait until you end your transaction. They receive the message “Record not available ... please wait” until the records become available. Because of this, it is important to keep the length of the transaction to a minimum or conduct the transaction during times when others do not need access.

Jim,

The help is telling me that there is a sort of exclusive lock which does other users keep from reading other records as long as a transaction lasts. Is the help describing the right behaviour or is this one of the infamous errors in the help documentation ?

Sam,

In addition to what Jim was saying. Transaction and buffering are often used together, but you can use transactions without buffering (not preferrable) and you can use buffering without transaction (common when only modifing one table).