dbexport lock question
IDS 12.10.FC3
Solaris 10 1/13
I attempted to use dbexport to get an ASCII dump of a database from an RSS. (I
first set STOP_APPLY to 1.) I executed 'dbexport -ss <database>'. About 50
minutes into the export, dbexport crashed. Here is 'tail' of the dbexport.out:
informix@ifmx-prod-jnu>tail out
outlook_cd integer,
comments char(256),
primary key (ofndr_cmnty_outlk_id) constraint "informix".ofndr_cmnty_outlk_id
) extent size 16 next size 16 lock mode page;
revoke all on "informix".ofndr_cmnty_outlk from "public" as "informix";
-244 - Could not do a physical-order read to fetch next row.
-107 - ISAM error: record is locked.
QUESTION: My understanding (I welcome correction if I am mistaken) is that
dbexport acquires an exclusive database lock. So, why does it crash due to a
locking conflict after 50 minutes of successful operation? I conclude that I
do not properly understand how dbexport operates.
Thank you for any clarification.
DG
Dave:
On a primary server, you are correct that dbexport takes an exclusive database
level lock. However, it cannot do that on an RSS secondary, so it has to deal
with locks from other sessions.
You could try using my dbexport replacement utility, myexport, which has
options to SET LOCK WAIT and other methods to insure data consistency. You can
download myexport from my web site at www.askdbmgt.com/my-utilities
Thank you, Art.
Yet, I wonder... if STOP_APPLY is set = 1 (which, I would think, means zero
writes are happening) then why can't dbexport put an exclusive lock on the
database?
DG