Re: When to use Berkeley transactions.

Greg Hudson wrote:

>You're right; given that we use transactions, I'm not sure why we have
>separate representations and strings tables.
>
>
Because we want to isolate node records from deltification. When we
deltify a file's contents, we create a completely new string (with a new
key) and delete the old one, but only modify the representation record
without changing its key. Nodes contain representation keys, and many
nodes can use the same representation. Using a separate table for the
strings means that we don't have to update all the nodes when we deltify
the contents, or indeed even maintain back references from
representations to nodes.

-- 
Brane Čibej   <brane_at_xbc.nu>   http://www.xbc.nu/brane/
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