Steve,
First, a caveat: I've never used mysql, so I could be totally off-base
here.
Perhaps this behavior is the result of some implicit transaction, so
the first SELECT begins a transaction, and the DBMS wants to present a
consistent view of the database (that is, return the same results), until the
transaction finishes, which it never does until you kill the program. If this
is true, then a simple work-around might be to wrap your SELECT statement in a
BEGIN TRAN and END TRAN, or mysql might have some way to "turn-off" the
implicit transaction.
Andy
-----Original Message-----
From: Steve Baldwin [mailto:[email protected]]
Sent: Monday, April 23, 2012 03:54
To: dbi users
Subject: Polling a table using DBD::mysql
Hi all,
This is driving me nuts.
I have a simple test case where I do something like this :
loop
select count(*) from some_table
sleep 2 seconds
end loop
My problem is that the count shows the number of rows the first time it
executes and from that point never changes.
While the program is running, I insert rows into the table from another
session but the count never changes. If I kill the program and restart it,
it shows the new count but again never changes.
Is this some quirk with mysql? It certainly doesn't behave that way using
DBD::Oracle.
I've tried several different methods of selecting the data but I always see
the same behaviour.
I'm using :
mysql version 5.5,
DBI version 1.609,
DBD::mysql version 4.013
Perl 5.10.1 (on Centos 6)
Thanks,
Steve
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