Thread: Possible problem when updating a record from two clients at the same time?

Possible problem when updating a record from two clients at the same time?

From
"K. Hoffrath"
Date:
Hi all.

I'm converting a dos based application using DBase files to PostgresSQL.
The application is a pawn shop management system.

The dos application works as follows:
Table A holds all items which the customers bring to the shop.
Table B has one record for each day which holds the totals for this
particular day.
When B is updated, the particular record gets locked, updated and
released.

The new application works this way:
- start a new transaction,
- insert the new record in A,
- the insert operation fires a trigger which updates B
- commit transaction.

Now my question:
What happens if two clients insert a new record to A at the same time?
Will B get updated correctly or will one value get lost?


Thanks in advance.

Karsten