When an application (say VB6) opens a database, .ldb file
is created. If another user opens the same database:
1. Will he be allowed?
Yes, additional users can open the file assuming that the first user did NOT
open the file in exclusive mode. There is provisions for opening a file in
exclusive mode, as some types of operations, or appcltions DO NOT want to
have more the one user in them.
2. Wont the .ldb file delete when either of the users
closes the database?
No, the ldb file gets deleted when the LAST user exits.
3. Does .ldb file really matter?
Yes, the file is critical to the operation of JET. This file is how the JET
data engine manages the multi user locking problems. Who is in the database,
and who currently has what records locked and in use is held in this file.
In fact, if JET cannot create the ldb file, then the JET opens the mdb file
in READ ONLY mode, as there would be no way to manage write conflict between
users. So, this file is critical to the operation of a JET mdb file. If by
some chance the directory where the mdb file is located does NOT have
create, and delete file permissions, then the mdb file is opened in read
only mode. So, users need both read, write, create, and delete permissions
to the directory where the mdb file resides.
Is there any special action to be performed for using
Access database in multi-user environment?
Nothing really special needs to be done, but your should trap errors when
you update data as perhaps another user already was editing that record.
You also have to choose what type of record locking you plan to use. There
is some good reading the ms-access help about choosing a record locking
strategy.
