> Try breaking down the A query with LIMIT/OFFSET so that it never holds
> locks for long. That way B will not wait for long, if at all, and will
> not fail.
Just as a remark, this will only work if the chunks can be processed in
separate transactions. If the whole thing is related and A must be
completely wrapped in a transaction, then the locks placed by the first
queries will still hold until the end of the transaction...
Cheers,
Csaba.