
CMU 15-721: In-Memory Databases / Advanced Database Systems [video] - skovorodkin
https://www.youtube.com/playlist?list=PLSE8ODhjZXja7K1hjZ01UTVDnGQdx5v5U
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lichtenberger
Great lecture so far. Haven't had the time to watch the whole lecture, but one
thing I want to mention is that there are techniques to improve the buffer
manager performance as for instance described here by Goetz Graefe:
[http://www.vldb.org/pvldb/vol8/p37-graefe.pdf](http://www.vldb.org/pvldb/vol8/p37-graefe.pdf)

I've implemented an even simpler solution for my Open Source Data Store
([https://sirix.io](https://sirix.io)) in that each page stores a number of
references, which are itself lightweight pointer objects (in Java) and it
simply stores an in-memory reference as well as a pointer to the location to
fetch it from disk/a flash drive. If the buffer manager has these Objects as
keys on eviction we can simply null the reference to the in-memory page
instance.

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dowakin
Also check out other courses from Prof. Andy Pavlo
[https://www.youtube.com/channel/UCHnBsf2rH-K7pn09rb3qvkA/pla...](https://www.youtube.com/channel/UCHnBsf2rH-K7pn09rb3qvkA/playlists)

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calpaterson
I find it hard to reconcile the incredible generousity of making this material
available for free on the internet with the cringeworthiness of Andy Pavlo's
style. I love the material but the "6th form humour" is really off-putting and
he doesn't need it.

See
[https://www.youtube.com/watch?v=m72mt4VN9ik&t=781](https://www.youtube.com/watch?v=m72mt4VN9ik&t=781)
for an example of what I mean

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balfirevic
> he doesn't need it.

Nobody needs anything. You didn't need to write your comment. And neither did
I have to write this one. That's terrible criteria to judge anything, if it
even means anything sensible at all.

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rgoulter
I'm fine with "it's down to taste".

"This course video doesn't need juvenile jokes" is an expression of taste. And
some people enjoy the jokes.

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manigandham
Check out the CMU database group for all the other content and the multiple
courses: [https://db.cs.cmu.edu/](https://db.cs.cmu.edu/)

Here's their Youtube channel:
[https://www.youtube.com/channel/UCHnBsf2rH-K7pn09rb3qvkA/fea...](https://www.youtube.com/channel/UCHnBsf2rH-K7pn09rb3qvkA/featured)

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jules
I've watched some of these and the material and teacher are awesome. Two
questions come to mind:

1\. A ton of effort seems to be spent on making things run in parallel, but
that introduces quite a bit of overhead too, so how well does a sequential
baseline actually perform? By sequential baseline I mean a single thread that
just executes all incoming transactions one by one in sequence.

2\. This course seems to spend a lot of time on things that the teacher says
are things you shouldn't do anyway. For instance there is an entire lecture on
skip lists and Bw-trees, and at the end the teacher mentions that these are
terrible. This is interesting from a historical perspective, but not only does
this take a lot of time, I also lose track of which things you should and
which things you shouldn't do. It'd be interesting to have a compressed course
that spends less time on things you should not do, perhaps by adding
annotations to the video to skip sections that are about things you should not
do.

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rohansuri
Do you have the link to lecture on SkipLists and Bw Trees?

Thanks

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jules
Lecture 7.

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cnbscience
Amazing material as always! feeling proud to be an alumni.

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arkj
That prof got sprayed on by a lady asking for 200 dollars (lecture 1, 13:00).
Anybody knows the background?

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thepete2
That has to be a joke, maybe meant to keep your attention. He has made cuts so
why else would he have kept it in?

