Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Datomic is Free

blog.datomic.com

Post reply on HN
Print view View original

61–70 of 436 posts

Re: Datomic is Free

#61

Post by mst »

I guess NuBank (Cognitect's owners) have concluded that the paid licensing business wasn't worth the hassle compared to having the developer time involved spent on other things.

Releasing only binaries, while I understand people being grumpy about it, seems like an interesting way of keeping their options open going forwards. Since it was always closed source, it now being 'closed source but free' is still a net win.

The Datomic/Cognitect/NuBank relationship is an interesting symbiotic dynamic and while I'm sure we can all think of ways it might go horribly wrong in future I rather hope it doesn't.

Re: Datomic is Free

#62

Post by motogpjimbo »

simtel20 wrote: post #41
endisneigh wrote: post #13

Earlier quoted context omitted.

to be honest the testimonials are terrible. > “Datomic added to DynamoDB was the only option that didn’t force us to sacrifice features or add the expense of developer time. Without it, we would have had to push back a lot more, as the features would have been too difficult.” ( https://www.datomic.com/the-brigades-story.html ) like, what? effectively useless information. some of the other testimonials mention keeping…

It's not simply revision history, it's a complete record of everything with time, without re-architecting your data or app. IIRC datomic structures your data so that all transactions and state have a time dimension so you can go forward or back in time trivially (no special query, no temporal sql, etc.)

What happens when you have a legal obligation to delete or anonymise data for some reason?

Re: Datomic is Free

#63

Post by roguas »

mbesto wrote: post #54
adamfeldman wrote: post #3

What is Datomic, you ask? It's a database written in Clojure. https://hn.algolia.com/?q=datomic Datomic is an operational database management system - designed for transactional, domain-specific data. It is not designed to be a data warehouse, nor a high-churn high-throughput system (such as a time-series database or log store). It is a good fit for systems that store valuable information of record, require developer…

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

You have to add a lot of scaffolding to postgres to make it semi-immutable. datomic just is, wanna know previous user email, just go back and see. Out of the box, without thinking about it.

Re: Datomic is Free

#64

Post by fulafel »

motogpjimbo wrote: post #62
simtel20 wrote: post #41

Earlier quoted context omitted.

It's not simply revision history, it's a complete record of everything with time, without re-architecting your data or app. IIRC datomic structures your data so that all transactions and state have a time dimension so you can go forward or back in time trivially (no special query, no temporal sql, etc.)

What happens when you have a legal obligation to delete or anonymise data for some reason?

There's https://docs.datomic.com/pro/reference/excision.html - but like in other data models you also might choose to not store sensitive infromation like PII in cleartext in the main DB at all. At least in earlier versions excision wasn't supported in the Datomic Cloud version.

Re: Datomic is Free

#65

Post by lolinder »

a2800276 wrote: post #56
lolinder wrote: post #42

Earlier quoted context omitted.

Making your product available for free isn't a publicity stunt, it's a huge step for a business. And, in practice, it's not that much different for the average user if only the binaries are Apache licensed. When was the last time you needed to open up the Postgres source code and modify something?

If it wasn't a publicity stunt, it certainly had the effects of one: I've never heard of Datomic before and here they are at the top of hackernews! > And, in practice, it's not that much different for the average user if only the binaries are Apache licensed. When was the last time you needed to open up the Postgres source code and modify something? Sure, if you're playing a game it probably doesn't make a difference…

Again, with your hypotheticals—when was the last time you needed to do any of that with Postgres or another FOSS DBMS?

For the vast majority of use cases, a FOSS DBMS and a free-as-in-beer DBMS are indistinguishable. If you're in a category where they're not, then don't use Datomic, but this is still far more than a publicity stunt.

Re: Datomic is Free

#66

Post by fulafel »

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 is Ions in the Cloud version, or for on-prem version the in-process peer library.

Re: Datomic is Free

#67

Post by nightski »

a2800276 wrote: post #56
lolinder wrote: post #42

Earlier quoted context omitted.

Making your product available for free isn't a publicity stunt, it's a huge step for a business. And, in practice, it's not that much different for the average user if only the binaries are Apache licensed. When was the last time you needed to open up the Postgres source code and modify something?

If it wasn't a publicity stunt, it certainly had the effects of one: I've never heard of Datomic before and here they are at the top of hackernews! > And, in practice, it's not that much different for the average user if only the binaries are Apache licensed. When was the last time you needed to open up the Postgres source code and modify something? Sure, if you're playing a game it probably doesn't make a difference…

Rich Hickey started Datatomic (along with Stuart Halloway & Justin Gehtland). He also created the Clojure programming language and has been on Hacker News numerous times with many popular talks. In fact they all have made famous contributions.

Many businesses use Microsoft SQL Server or Oracle and don't need access to the source. I'm not saying open source isn't nice, but it is absolutely not a requirement for IT infrastructure.

I'd imagine people rely on many cloud services that are in fact, not open source.

Re: Datomic is Free

#68

Post by evantbyrne »

roguas wrote: post #63
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?

You have to add a lot of scaffolding to postgres to make it semi-immutable. datomic just is, wanna know previous user email, just go back and see. Out of the box, without thinking about it.

Immutability is certainly tempting for certain kinds of data. Does it handle use-cases where data needs to be deleted though? i.e., privacy compliance.

Re: Datomic is Free

#69

Post by augustl »

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…

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, as they don't have to coordinate.

There's also the performance and practicality benefits you get from not having to do round-trips in order to query. You can now actually do 100 queries in a loop, instead of having to formulate everything as a single query.

And if you have many different apps that operates on the same DB, it becomes a benefit as well. The app server will only have the _actual_ working set it queries on in memory, not the sum of the working set across all of the app servers.

If this becomes a problem, you can always architecture your way around it as well, by having two beefy API app servers that your 10s or 100s of other app servers talks to.

Re: Datomic is Free

#70

Post by fulafel »

mbesto wrote: post #54
adamfeldman wrote: post #3

What is Datomic, you ask? It's a database written in Clojure. https://hn.algolia.com/?q=datomic Datomic is an operational database management system - designed for transactional, domain-specific data. It is not designed to be a data warehouse, nor a high-churn high-throughput system (such as a time-series database or log store). It is a good fit for systems that store valuable information of record, require developer…

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

A tangent but it would be interesting to see survey data of how many devs default reach for SQL first these days. A lot of people use various other kinds of DB models which are preceived to have smoother learning curves.
Post reply on HN