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Re: back-bdb deadlocks?
David Boreham wrote:
Next major = 5.xx?
I think it might make it into the next 4.x release.
It turns out that a simple patch to BDB is all that's needed (see
Hmm. It's not documented that you can pass
DB_TXN_NOT_DURABLE to DB->txn_begin(),
but perhaps that's a doc bug.
No, you can't by default; that's what the attachment in my previous
email is for. I posted a patch to BerkeleyDB and a patch to back-bdb,
you must have missed the BerkeleyDB patch in the attached dif.txt...
But this will not give you Level 2 Isolation.
You will still be acquiring read page locks under your
long lived transaction. Eventually I suspect that
you will overflow the lock table, or worse
deadlock with a writer thread.
The back-bdb code explicitly releases all the page locks (lock_vec(),
DB_LOCK_PUT_ALL) so there's no problem here.
-- Howard Chu
Chief Architect, Symas Corp. Director, Highland Sun
Symas: Premier OpenSource Development and Support