Subject "Page type 5 lock conversion denied" Error
Author Greg Kay

We've just had a problem with a lock conflict in Firebird Classic
2.03. We got the error message

Page 708341, page type 5 lock conversion denied.

We had two batch jobs running that interfered with each other.
Normally we handle lock conflicts by rolling back the transaction that
got the lock conflict and retrying the same SQL statements. This is
usually OK but with this particular rollback, the record with the
conflict and the "lock conversion denied" error was not rolled back
causing a primary key error in the next retry.

Has anyone come across this error?

We're running Firebird Classic 2.03 on Linux OpenSuse 10.2 x86-64 with
about 150 connections during peak times.