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Development Team/Datastore Rewrite (view source)
Revision as of 09:47, 23 September 2008
, 09:47, 23 September 2008→Design
This improves storage efficiency in general, but in our case is more important because we wish to record in the journal several interactions that refer to the same file. For example, "Downloaded lesson3.pdf", "Read lesson3.pdf", "Sent lesson3.pdf to Juan" would all refer to the same file and we need to only store it once.
This improves storage efficiency in general, but in our case is more important because we wish to record in the journal several interactions that refer to the same file. For example, "Downloaded lesson3.pdf", "Read lesson3.pdf", "Sent lesson3.pdf to Juan" would all refer to the same file and we need to only store it once.
== Layout on disk ==
The proposed implementation relies heavily on the data structures provided by the filesystem, thus the layout in which files are disposed on disk is a fundamental part of its design.
Example of a datastore containing 5 entries, two of them referring to the same file (with checksum 464493d8d929436b6152e868867ed451):
1a
1ab88287-766a-4d98-a7c0-4233dc48647a
1ab88287-766a-4d98-a7c0-4233dc48647a
metadata
2b
2b90597c-0912-4e7f-8eeb-71a0f004490d
2b90597c-0912-4e7f-8eeb-71a0f004490d -> checksums/464493d8d929436b6152e868867ed451
checksum ~> checksums/464493d8d929436b6152e868867ed451
extra_metadata
preview
metadata
3c
3cdf5f0e-7595-4166-b1f9-cbedfcfe1c4a
3cdf5f0e-7595-4166-b1f9-cbedfcfe1c4a -> checksums/464493d8d929436b6152e868867ed451
checksum ~> checksums/464493d8d929436b6152e868867ed451
extra_metadata
preview
metadata
4d
4db11d29-2f07-4452-bd8e-22a6a483ac19
4db11d29-2f07-4452-bd8e-22a6a483ac19
metadata
extra_metadata
preview
5e
5e9f2027-b41e-4015-a848-6b3972193eb8
5e9f2027-b41e-4015-a848-6b3972193eb8
metadata
extra_metadata
preview
checksums
index