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#datomic
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2016-12-17
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idiomancy01:12:25

Okay, so, it seems like datomic a is pretty well suited for replacement for append only relational models. Is there anywhere online that details a) how to build a relational, append-only database model and b) where that strategy falls apart. I need to be able to answer the question "what problem are we trying to solve here?" when I sell this as our database system for our next service

thedavidmeister06:12:28

@idiomancy “what problem are we trying to solve” doesn’t seem related to questions a. and b.?

idiomancy11:12:52

In my particular case, its highly related. We'll be doing a change history table in cassandra or sql if I cant make the case for datomic

thedavidmeister13:12:58

@idiomancy ok well i’ve worked with revision history tables before in sql

thedavidmeister14:12:14

with version ids, etc.

thedavidmeister14:12:52

it’s not as powerful or elegant as being able to run queries “as at” a time, or being able to apply “what if” diffs to a db

thedavidmeister14:12:25

certainly trying to emulate exactly what datomic does by hand in sql sounds like a bad idea

idiomancy14:12:09

revision history might not be the right way to put it. we're actually maintaining a record of all the changes that happen to customers. (so when they change their birthday in the system or opt in to other features, or what have you)

lvh15:12:32

Is the Datomic DynamoDB schema public and considered stable API? I’m building a dataset that I think datomic will be useful for at some point — I’d like to make it as easy as possible to sprinkle some sample Datomic on it down the line.

lvh15:12:58

(It would already be EAVT-ish.)

Lambda/Sierra16:12:02

@lvh: Datomic uses all storage backends as simple key-value stores to hold compressed chunks of its indexes. You cannot mix storage-native queries or data with Datomic data.

lvh16:12:26

ah; too bad

lvh16:12:36

ETL it is/shall be then

thedavidmeister17:12:39

@idiomancy even if you maintain a record of all the changes for a customer, how do you build functionality on top of that?

thedavidmeister17:12:01

how does it tie into an orm?

thedavidmeister17:12:26

how does sql help you replay/snapshot history?

thedavidmeister17:12:25

if all you want is conceptually just a log, then sql is probably fine

thedavidmeister17:12:29

but trying to ask historical questions of a relational db, even if it is append only, sounds like a lot of gnarly code to write