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0 points6345dhjdsf2y ago0 comments

(Posted under a different account because I'm being slow-posted again by HN)

> In theory, the DBMS itself could directly support 'physical denormalization' and make this performance optimisation easier to implement and transparent to the application code. I think some SQL DBMSs have attempted to do things like this.

Automatically managed, application-transparent, physical denormalisation entirely managed by the database is something I am very, very interested in. Unfortunately I've been able to find pretty well nothing to describe what it would look like and how it would be done. If you can provide any links that would be so incredibly helpful!

It gets mentioned in the Date/Darwen books as being the right way to do things, but no actual information seems to be given.

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jimwhite422y ago

I'm a bit fuzzy, but I think Vertica allows duplicating tables stored in multiple orders - then I think the appropriate version is picked automatically by the query optimiser. So this works not that differently to an index (which is also dbms managed performance denormalization).

There's also materialized views - if you have automatic incrementally updated materialized views, which are transparently substituted into queries, that's along these lines. I think there's a lot of progress being made here, and plenty of compromises used in the field that have been in production for a long time.

I think there's some ambitious work on materialized views being done in postgres.

> It gets mentioned in the Date/Darwen books as being the right way to do things, but no actual information seems to be given.

I don't think they ever convincingly got into the details on it.

6345dhjdsfOP2y ago

> So this works not that differently to an index

Yes, it's pretty much the same as a covering index is used

> There's also materialized views

Ah yes, that's pretty much the answer (if incrementally updated). Thanks.

smaddox2y ago

> Automatically managed, application-transparent, physical denormalisation entirely managed by the database is something I am very, very interested in.

Sounds a bit like Noria: https://github.com/mit-pdos/noria

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