[ZODB-Dev] tid vs. serial

Vincent Pelletier vincent at nexedi.com
Mon Oct 18 08:53:46 EDT 2010


Hi.

During my presentation of NEO at DZUG, Cristian Theune told me that I might be 
confusing tids and serials. And indeed, I could not define the difference 
between them. 

Then I thought about it, and I came to the idea that one of them is only valid 
during some time (probably only during 2PC) while the other is persistently 
valid.

This means that having just the persistent one is not incorrect, but might add 
bigger constraints on transaction commit order (transaction number cannot 
decrease, etc), explaining why we don't see any "persistent problem" (data 
corruption, etc) when misused.

Is this right ?
If there is any documentation on this ?

Regards,
-- 
Vincent Pelletier


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