Subject What can be the possible cause for this lock
Author Johannes Pretorius
Good day all

I want to thank everybody for all the help with the
queries regarding " Transaction and Stored procedures." and "Triggers/Stored procs and Locks"

I have the following scenario we have problems with, and I want to ask if somebody can give us ideas on
why this will happen

In this scenario lets say we have 3 types of clients
A) Client A that INSERTS and UPDATES data into database and refreshes data from stored procedure.
B) Client B that does updates on 1 table common with A's inserts and 1 not affected by A at all (second one is inserted into by B).
C) Client C that polls table only inserted to by A and reacts by inserting into it's own table not affected by others.

The problem.

When A Inserts data into database and B and C is running, then it sometimes happens that A gets a deadlock when creating (INSERTING) the data into
the database. Please note that B cannot work on data UNTIL A has inserted it, thus B does not have affect on this. Thus the only client that
is suppose to affect this process is C. But C only reacts on newly INSERTED data. After data is process by it is DELETED from table (All tables
has UNIQUE identifiers and primary keys).

Can this be related to the transaction type (isolation) or just bad coding beeing missed somewhere ?

Information about database and machines
Version : Interbase 5.6
OS : Windows NT & 2000
DB Size : From 400 mb till under 4GB.
Force writes is ON

Thanks in Advance for any help and time.

Johannes Pretorius
(Programeerings Departement- Promed)

Tel : +27 11 607-3300
Faks : +27 11 622-6939
webtuiste :


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