Configuring Paradox to run in a network environment

CONFIGURING THE BDE TO RUN PARADOX IN A NETWORK ENVIRONMENT
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In order for Paradox to operate in a multi-user environment, every user must have the NET DIR setting in the BDE pointing at the PDOXUSRS.NET file. This file is responsible for tracking users who are logged on, and which records and tables they are accessing. The NET DIR setting corresponds to the directory that this file is centrally located in. Everybody must have full access to this directory, so that Paradox knows at all times, who is accessing a table, and what record they are in. The location of the .NET file is irrelevant, the only imperative is that everyone has their BDE pointed at it via NET DIR.
If everybody is not pointing at the same .NET file, or a user has not got full rights to this directory, then locking problems can occur, the system has not got a correct picture of who is accessing what, and therefore data integrity is violated.

The following setting illustrates a valid NET DIR entry :

<Drive> : \ServerOne\PDox

Users can enter different drive letters, depending on which drive theyÆve mapped to the directory containing PDOXUSRS.NET, but the rest of the path must be identical.

Example :

There are four users on a network, running Paradox.
There is a server on the network containing various databases, the main directory for Paradox files being \\SERVER1\DATA\PARADOX.

User #1 maps his F: drive to \\SERVER1. Then does the following ....

1. Opens the BDE and clicks on the configuration tab

2. Expands Drivers | Native, then clicks on Paradox

3. Clicks inside the NET DIR window, and either browses for Pdoxusrs.net ..... or.....

4. Types F:\DATA\PARADOX

5. Applies his changes and exits the BDE


Users #2, #3 and #4 can have different drive letters, but they must have :\DATA\PARADOX
after the drive letter (and obviously be mapped to the same server.
Once everybody has done this, they are ready to use Paradox on a network.

Be aware of opportunistic locking

æOpportunistic locking is a feature in Windows that is enabled by default, and will cause problems in a database environment - Its best to leave locking to Paradox and the BDE, so you might want to disable it.

The feature is located in Control Panel | System | Performance | File System | Troubleshooting, then place a checkmark in æDisable new file sharing and locking semantics'. While you're in there, you might also æDisable write behind caching for all drives' - this can cause corruption in indexes\tables, "index out of date" messages etc.

Opportunistic locking basically means that NT writes to disk when ever it has some spare time. In a multi user database this just doesn't work.