Details
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Type:
RFC
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Status: Withdrawn
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Resolution: Done
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Component/s: DM
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Labels:None
Description
The current baseline is modeled support the following shared scans:
- Object for the latest DR only
- Object_extra for the latest and latest-1 DRs
- Source for the latest DR only
- ForcedSource for the latest DR only
Note that with the exception of Object_extra, we are planning to support efficient full-table-type access to the latest data release only. Short non-scan queries will be supported for any data release available on disk (per baseline, that'd be latest and latest -1).
I'm soliciting comments and reactions. Changing the model and providing access to older data release is not a technical problem, it is only a question of $ (how much hardware to purchase).
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John Swinbank, Wil O'Mullane Given that the work associated with this RFC was invalidated, should we withdraw this RFC?
I think we should solicit opinions from Fritz Mueller & Colin Slater first.
I haven't seen any places where these choices actually drive implementation choices, so I have understood this as "suggestions" for some future policy closer to ops.
(On a technical side, it seems crazy to have databases that don't allow a table scan at all. I have never fully understood what Jacek was proposing here.)
Colin Slater
added a comment - I haven't seen any places where these choices actually drive implementation choices, so I have understood this as "suggestions" for some future policy closer to ops.
(On a technical side, it seems crazy to have databases that don't allow a table scan at all. I have never fully understood what Jacek was proposing here.)
I don't think that the supposed baseline was actually implemented in the sizing model, and in any case the disk drive count in the sizing model is constrained primarily by storage, not bandwidth.
So I'd suggest that we withdraw this RFC.
(Sorry about the reassignment; it was due to an accidental typo and fixing it will cause more unnecessary spam.)
Based on input received, it looks like we should tweak the baseline and support shared scan access to at least 2 most recent data releases. Next step will be to run it through spreadsheets and come up with the $ number.