General HydroStatics
Ship Stability Software
Command of the Week
(New or interesting aspects of GHS that you may not know about)

DB Secure
(Requires GHS version 17.00 or later)

(Use the command DB Update to get the latest version of the Data Base software.)

What happens if two GHS sessions (either on the same computer or on separate computers using a network drive) try to use the Data Base simultaneously? As long as each session is dealing with a different Ship (Geometry File) there is no restriction on simultaneous access.

Additionally, the same Ship folder can be accessed by two or more GHS sessions in a quasi-simultaneous manner, meaning that the DB commands work but cannot overlap in time. Session A is locked out during the time that session B has a DB command in process.

For example, if someone is editing the fixed-weight store using DB EditFixWt, another session would have to wait until that editing session is over before issuing a DB command.

Here is what happens if session A is in a DB dialog and session B tries to issue a DB command with the same Ship. Session B gets this response:

The "Go ahead" button defeats the lockout and goes ahead with the session B command. This is generally not useful unless you know that there is no other session actively accessing that Ship. The date and time of the last access are shown, which may be evidence that no other session is currently active.

If you want to secure your session from any other session attempting to use the same files, the command DB Secure is available. Before you end the session, be careful to turn off the "secure" setting or you will be locked out along with everyone else from then on.

Fortunately DB Unlock, which turns off the secure setting, can be used at any time, and it will restore access if someone forgets to turn off the secure setting.

By the way, DB Proj does not operate under this rule since it does not involve a particular Ship folder. Simultaneous use of DB Proj in separate sessions is possible and is discussed here.

Questions, comments, or requests?
Contact Creative Systems, Inc.

USA phone: 360-385-6212 Fax: 360-385-6213
Office hours: 7:00 am - 4:00 pm Pacific Time, Monday - Friday

Mailing address:
PO Box 1910
Port Townsend, WA 98368 USA

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