datomic

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JohnJ 2021-01-28T01:29:30.063300Z

attribute predicates were applied on retractions too? or what was the issue here?

favila 2021-01-28T15:03:34.063800Z

Yes, they were applied on retractions too, mostly

JohnJ 2021-01-28T15:55:18.064100Z

what problems did it cause?

favila 2021-01-28T15:59:34.064300Z

If you have existing data that violates a predicate, you can’t add the predicate you want and then get rid of bad data. You have to either compromise the predicate to fit the bad data you have (possibly allowing new bad data); or you have to get rid of the bad data first, install the predicate, then check your data again (retractions of bad data may fail in the meantime), and possibly remove the predicate and repeat.

JohnJ 2021-01-28T16:13:34.064500Z

got it, thx

JohnJ 2021-01-28T16:28:34.064700Z

I wonder why they didn't took the approach of "all data must satisfy the predicate before the attribute predicate can be added".

favila 2021-01-28T16:30:50.064900Z

That would be a (potentially long) blocking transaction

JohnJ 2021-01-28T17:43:43.065100Z

If you don't mind, besides HA, does clubhouse runs more than one transactor to serve customers?

favila 2021-01-28T17:46:16.065300Z

only one, for now. We’re working on sharding.

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