Skiplist / best practice for 2.1 branch

[Rob Siemborski]

On Mon, 18 Nov 2002, Patrick Boutilier wrote:

> I tried those stability patches and they didn't help. The only thing
> that stopped lmtp from hanging was switching from db3_nosync to
> skiplist. What are the advantages of using db3_nosync over skiplist?

db3_nosync uses the Berkeley DB backend, which should be faster than
skiplist for random access.  Also, since the duplicate delivery database
doesn't *need* consistancy, the lack of syncing to disk (which skiplist
probably does more than is strictly necessary) makes it much faster to
update than skiplist ever could be.

Skiplist's main advantage is that it can enumerate the database much
faster than the other backends (except for flat, possibly), and avoids the
massive cost of updates present in flat.

-Rob

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Rob Siemborski * Andrew Systems Group * Cyert Hall 207 * 412-268-7456
Research Systems Programmer * /usr/contributed Gatekeeper