[HN Gopher] XTDB 2.x Early Access ___________________________________________________________________ XTDB 2.x Early Access Author : gemstones Score : 85 points Date : 2023-04-27 19:42 UTC (3 hours ago) (HTM) web link (www.xtdb.com) (TXT) w3m dump (www.xtdb.com) | kevinmershon wrote: | We use XTDB 1 and have a multi replica production instance with | about 600GB of data at ~100 million transactions. The biggest | problem we have is with minor versions bumping the underlying | RocksDB i dex version, requiring a full reindex of the main | "golden" data store taking days to weeks. | | AFAIK this is not solved in XTDB 1. I'm hoping XTDB 2 provides a | better upgrade path for modestly sized databases like ours. | refset wrote: | XTDB 2 will compute and maintain incremental indexes on-the-fly | based on the raw data, so index updates will present far less | operational impact. This also means the transaction log is now | ~ephemeral in the new architecture (no more event-sourcing- | style replays required, ever). | kevinmershon wrote: | That is incredibly exciting! Glad to hear it. | vosper wrote: | My understanding is the XTDB is either a fork of Datomic, or was | inspired by it? I suppose it's timely, given the top story on HN | right now is "Datomic is Free" [0] | | Is there anyone who's familiar with both and would like to share | their thoughts on the two? | | https://news.ycombinator.com/item?id=35727967 | newlisp wrote: | They have completely different data models though, XTDB is a | schemaless document data store, think mongodb but with | SQL/Datalog querying and bi-temporality. | | Datomic's data model is something they call the 'universal | schema' where you just specify the attributes and then create | entities however you like from them. Datomic aligns more with | how you structure data in Clojure, avoiding the impedance | mismatch. | refset wrote: | Datomic's "immutable database + Datalog" was definitely the | biggest source of inspiration but XTDB has a lot of differences | - I wrote this FAQ entry up a few years back: | https://docs.xtdb.com/resources/faq/#comparisons (note this | comparison is for XTDB 1.x and Datomic On-Prem only, so needs | revisiting!) | | Arguably the biggest difference is that XTDB has a schemaless, | dynamic core. Having a sane schema is of course important when | building complex things, but we believe that the flexibility to | experiment with schema (fully) in userspace is essential for | moving the state of the art forwards. For instance a lots | Clojure users these days prefer relying on | https://github.com/metosin/malli for _all_ their schema needs. | baq wrote: | > XTDB is a bitemporal and dynamic relational database for SQL | | You have my attention. I actually raised an eyebrow reading that, | last time this happened was when ChatGPT was released. | | Temporal is a world of pain in SQL, bitemporal... nice. | | edit: for those who haven't heard what bitemporal is, Wikipedia | has an example: | https://en.wikipedia.org/wiki/Temporal_database#Using_two_ax... | seabass-labrax wrote: | XTDB is a very interesting database to me. Not only is it | distributed, but the 'bi-temporality' which is mentioned on this | page means that it has essentially a built-in audit trail | mechanism. I'm working on writing an RDF library for Clojure, and | am looking forward to seeing whether XTDB really is as good as an | RDF datastore as I suspect it is! ___________________________________________________________________ (page generated 2023-04-27 23:00 UTC)