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Datomic is Free

blog.datomic.com

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Re: Datomic is Free

#161

Post by augustl »

epolanski wrote: post #158
augustl wrote: post #11

Datomic's is perfect for probably 90% of small-ish backoffice systems that never has to be web scale (i.e. most of what I do at work). Writing in a single thread removes a whole host of problems in understanding (and implementing) how data changes over time. (And a busy MVCC sql db spends 75% of its time doing coordination, not actual writes, so a single thread applying a queue of transactions in sequence can be fast…

> Datomic's is perfect for probably 90% of small-ish backoffice systems that never has to be web scale (i.e. most of what I do at work). So is any cloud-managed db offering and at that scale we talking very small costs anyway. Why datomic instead?

Because of the reasons I list :) Anything in particular that wasn't clear/relevant?

Re: Datomic is Free

#162

Post by CrimsonCape »

Since the conversation seems to be focusing on the Apache 2.0 license, what would you do? Clearly there isn't a lot of precedent for "closed-source, free-to-use" licenses.

In this case Datomic maintains development control over their product and "source of truth" is still themselves, and the implicit assumption is that you enthusiastically use their product for free with no strings attached because you respect them as the source of truth.

Re: Datomic is Free

#163

Post by [deleted] »

dimitar wrote: post #115
electroly wrote: post #53

Earlier quoted context omitted.

> Someone needs to have the working set of your database in memory, why shouldn't it be your app server and business logic? This one confused me. The obvious reason why you don't want the whole working set of your database in the app server's memory is because you have lots of app servers, whereas you only have one database[1]. This suggests that you put the working set of the database in the database , so that you s…

Consider this use case - in addition to your web app, you have a reporting service that makes heavy duty reports; if you run one at a bad time, bad things might happen like users not being able to log in or do any other important work, because the database is busy with the reports. So in a traditional DB you might have a DBA set up a reporting database so the operational one is not affected. Using Datomic the reporti…

[deleted]

Re: Datomic is Free

#164

Post by xmlblog »

electroly wrote: post #53
augustl wrote: post #11

Datomic's is perfect for probably 90% of small-ish backoffice systems that never has to be web scale (i.e. most of what I do at work). Writing in a single thread removes a whole host of problems in understanding (and implementing) how data changes over time. (And a busy MVCC sql db spends 75% of its time doing coordination, not actual writes, so a single thread applying a queue of transactions in sequence can be fast…

> Someone needs to have the working set of your database in memory, why shouldn't it be your app server and business logic? This one confused me. The obvious reason why you don't want the whole working set of your database in the app server's memory is because you have lots of app servers, whereas you only have one database[1]. This suggests that you put the working set of the database in the database , so that you s…

Having the working set present on app servers means they don't put load on a precious centralized resource which becomes a bottleneck for reads. The peer model allows app servers to service reads directly, avoiding the cost of contention and an additional network hop, allowing for massive read scale.

Re: Datomic is Free

#165

Post by erichocean »

jchw wrote: post #30

Not complaining about the actual announcement itself here: seems pretty sweet all things considered, But: the "Is it Open Source?" section should lead with "No." It's not a complicated question, and it's not a complicated answer. I think it's weird to talk about having "all the same rights" without explaining why that matters particularly (it does matter, it's just not explained much!) but it is somewhat tangential t…

Eh, it's Java bytecode and it's Apache 2. So you can patch Datomic and extend it without breaking the license.

Re: Datomic is Free

#166

Post by a2800276 »

xmlblog wrote: post #97
a2800276 wrote: post #77

Earlier quoted context omitted.

We must be working in a different world. In all my career I've not once worked with a serious business that did not have a support contract for their database system open source or not. Most of those had escrow agreements for central closed source components with vendors in case the vendor went out of business. (obviously only for things perceived as critical and from companies with some perceived risk of failure). A…

Free beer binaries are not mutually exclusive of Enterprise support agreements featuring all those things you mentioned above _for people that need that_.

Completely agree. I'm fine with a free beer license. The context of the post is that the binary is licensed using an Open Source license which leads to confusion.

Re: Datomic is Free

#167

Post by xmlblog »

augustl wrote: post #69
electroly wrote: post #53

Earlier quoted context omitted.

> Someone needs to have the working set of your database in memory, why shouldn't it be your app server and business logic? This one confused me. The obvious reason why you don't want the whole working set of your database in the app server's memory is because you have lots of app servers, whereas you only have one database[1]. This suggests that you put the working set of the database in the database , so that you s…

It's definitely a trade-off! If you have 10s or 100s of app servers that has the exact same working set in memory, it's probably not worth it. But if you have a handful of app servers, it's much more reasonable. The relatively low scale back-office systems I tend to work with typically has 2, max 3. Also, spinning up an extra instance that does some data crunching does not affect the performance of the app servers, a…

> If you have 10s or 100s of app servers that has the exact same working set in memory, it's probably not worth it.

The introduction of intelligent application-level partitioning [1] and routing schemes can help one balance cost and performance.

[1] https://blog.datomic.com/2023/04/implicit-partitions.html

Re: Datomic is Free

#168

Post by carry_bit »

electroly wrote: post #106
augustl wrote: post #69

Earlier quoted context omitted.

It's definitely a trade-off! If you have 10s or 100s of app servers that has the exact same working set in memory, it's probably not worth it. But if you have a handful of app servers, it's much more reasonable. The relatively low scale back-office systems I tend to work with typically has 2, max 3. Also, spinning up an extra instance that does some data crunching does not affect the performance of the app servers, a…

SQLite provides a similar benefit with tremendous results using its in-process database engine, although the benefit there is more muted by default because of the very small default cache size. We do have one app where we do this. There's no database server, the app server uses SQLite to talk directly to S3 and the app server itself caches its working set in memory. I can definitely see the benefit of some situations…

AIUI, the full peer is Datomic; the RPC server is just a full peer that exposes the API over http and is mainly intended to be used with clients that don't run on the JVM (and so can't run Datomic itself in-process).

Re: Datomic is Free

#169

Post by slaymaker1907 »

alecco wrote: post #92
mbesto wrote: post #54

Earlier quoted context omitted.

For 90% of the web devs that just spin up Postgres/MySQL, why would you use Datomic over that?

Just the temporal properties alone make it very useful for anything where it matters like billing, finance, inventory. Else you are in views/schema/indexing hell to do it on top of SQL. There is some SQL temporal support but it's not great and varies a lot. Also since it's not native to the storage it has a lot of complexity issues under the rug making it not great. Many financial systems use Event Sourcing (OOP + OR…

The temporal support seems handy, but time is still going to be really tricky for financial systems. Datomic only covers what the physical state of the database was at a particular time, but there's also the effective legal time (maybe a payment was dated a day before the system actually processed it) as well as requirements to remove data after a period of time (including point in time stuff).

Re: Datomic is Free

#170

Post by beders »

Every single day I wish the architects at my current job had chosen Datomic instead of Postgresql. It would have saved us so so much time and trouble. The time traveling ability alone would have been so useful so many times.

Also the ability to annotate transactions is awesome.

So many goodies.

Here's a good summary:

https://medium.com/@val.vvalval/what-datomic-brings-to-busin...

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