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0 pointsrefset7y ago0 comments

> time as a first class citizen

It's worth noting that time now has two levels of meaning in this context - transaction time and valid time.

Disclosure: working on Crux

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maximente7y ago· 1 in thread

hey, thanks for the reply. could you highlight the differences between Eva and Crux as you see them, today?

i do like passing in a timestamp and getting the state of the world as Crux seems to implement, whereas Eva seems slightly less oriented on time based querying, more so for a sort of log setup (where they have EAV+T+added?)

refsetOP7y ago

Well, Eva overlaps very closely with Datomic so I would recommend taking a look at the FAQ entry I wrote on the Crux/Datomic comparison (with 8 sections covering the major differences!): https://juxt.pro/crux/docs/faq.html#_comparisons

`EAV+T+added?` is the canonical data representation used by Eva, whereas Crux relies on two discrete "document" and transaction logs as the canonical representation. There are many reasons for this (data eviction, "unbundled" scalability etc.) but bitemporality (i.e. the ability to transact into the past/future) is definitely the primary reason why Crux doesn't follow the `EAV+T+Added?` pattern. You can get a feel for the indexes Crux uses here: https://github.com/juxt/crux/blob/master/src/crux/codec.clj#...

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