Multi-User Features

… more robust database sharing

ChemFinder has fairly intricate scheme for handling database access, dealing with such issues as multi-user file sharing and read-only access. In ChemFinder 5, we have reengineered the scheme for compatibility with new database mechanisms, and in the process have increased reliability and added features.

Updated 16 Jun 98 for Alpha2

Read-Only Database Access

When you open a ChemFinder database, you can interact with the data in one of two ways:

[ Note: A third possibility, Exclusive Access, is available through CAL, but is not fully supported at present.]

Under normal circumstances, the user may choose to open a database in either mode. However, if the database is write-protected, the program will override the user's choice and insist on read-only mode.

A database will be opened for read-only access:

When a database is open for read-only access:

If a database and/or form has been opened read-only, you can change it to normal access, or vice-versa.  You can choose File Database or right-click on the form and choose Database, then re-open the database in the desired mode.  Prior to Alpha2, this did not work.

Testing Suggestions

Multi-User Access

When two or more users open a ChemFinder database simultaneously, the open method used by the first may affect the others. There are three scenarios to consider:

[ Note: While we are not yet fully supporting exclusive access, there is a method for using it to determine whether another user has a database open in any mode. Try opening a database exclusively, using the following CAL command:

If the database is in use, the attempt will fail. ]

Testing Suggestions