On Thu, 26 May 2005, Tom Lane wrote:
Alvaro Herrera <[EMAIL PROTECTED]> writes:
I'm wondering what should happen at prepare time so that "my own cache"
is correct.
Good point. As far as the local caches are concerned, we probably have
to make it look like the transaction rolled back. I think Heikki
already had code in there to send the right inval messages when the
prepared transaction ultimately commits ... but we'll have to check that
that sequence does the right things ...
Looking at the sequence, at least the relcache init file stuff looks if
not broken at least a bit heavy-handed...
BTW: Is there a race condition in the relcache init file invalidation,
even without 2PC?
AtEOXact_Inval does basically this:
1. Unlink init file
2. Send inval messages
3. Unlink the init file again
Now consider this scenario:
backend A: Do updates that cause an init file invalidation
backend A: Commit begins
backend A: unlink init file
backend B starts and recreates init file
backend A: send inval message
backend C starts and reads the now stale init file
The window is admittedly very small, but it just caught my eye. Or am I
missing some lock etc?
- Heikki
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