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Hi All, I wrote an application making ‘advanced’ use
of transactions. The application is not tied to a specific kind of database. It
runs fine on oracle, db2, sql server but I run into a deadlock on postgresql. I have two transactions (let’s say A & B). These
two transactions are initiated by the same thread and I’m alone on the
database and the problem can be reproduced at will on postgresql. So this is
not a random problem. I try to understand what I see in the pg_locks table
but it looks like what is found there should never occur according to the
manual… At deadlock time: For transaction A, I have
a RowShareLock on table X. I have no idea on how/why this RowShareLock is
acquired by my application. In transaction A, I never read/write ‘directly’
to the table X. However I create data in other tables that have foreign keys to
table X. -> Is there more
information available somewhere in postgres system tables ? -> Could these foreign
keys be the cause of this RowShareLock ? For transaction B, I have
a AccessShareLock, ExclusiveLock and RowExclusiveLock on table X. -> According to the
manual, ExclusiveLock occurs only on system tables. -> Is there a way to
find why this lock is acquired ? Do you know tools to help in debugging this ? Any help is appreciated… Thanks in advance |
