Ask HN: What could a modern database do that PostgreSQL and MySQL can't • Hacker News Board

Re: Ask HN: What could a modern database do that PostgreSQL and MySQL can't

#61

Post by iudqnolq » Sun, Sep 05, 2021, 8:38 PM UTC

karmajunkie wrote: post #56

iudqnolq wrote: post #55

Earlier quoted context omitted.

Business usage is observed over time instead of known up front though. In a way this is sort of like the query planner. Couldn't your usage be observed and used to determine appropriate indexes?

i’d be more interested in an automatic index “suggester” based on observation and slow query analysis. there’s also the matter of new use cases where you’d absolutely want to be able to create them manually.

Absolutely. I'm increasingly in favor of generated code you check into source control.

Re: Ask HN: What could a modern database do that PostgreSQL and MySQL can't

#62

Post by withinboredom » Sun, Sep 05, 2021, 8:42 PM UTC

zz865 wrote: post #58

My biggest problem with databases is always versioning. IE renaming a column will break old clients. If there was a way you could have multiple schema versions so you could upgrade database then clients later it would be the best. EDIT: yes thanks for the comments, views and creating and API layers and adding instead of subtracting do all work, but I believe they're all workarounds for the underlying problem. Fixing…

The ideas is not to validate your schema in a client during runtime. Just like you don’t care if a new key is present in a json blob. You should be able to add new features without breaking things.

Re: Ask HN: What could a modern database do that PostgreSQL and MySQL can't

#63

Post by cornel_io » Sun, Sep 05, 2021, 8:43 PM UTC

spicybright wrote: post #2

I'm extremely out of my expertise here, but I'll see if I can spark some conversation. While possible with older SQL's through your own code, distributed sharding and keeping multiple databases in sync I would think be useful at a DB level vs user code level. You can certainly argue that shouldn't be part of the database software though.

If you've ever used Spanner you'll quickly decide that it absolutely makes sense for the DB to handle almost all of this stuff itself, it's a wonderful system that is sadly prohibitively expensive for many (most?) use cases outside of Google.

Re: Ask HN: What could a modern database do that PostgreSQL and MySQL can't

#64

Post by deergomoo » Sun, Sep 05, 2021, 8:44 PM UTC

I am yet to actually use it for anything, but I like the sound of what EdgeDB is doing [0][1].

The tl;dr is that its schema definitions and query language align much more closely to typical app logic, theoretically eliminating the draw of an ORM and being very good at things that are unwieldy with SQL, like retrieving sets of related records.

[0] https://www.edgedb.com/showcase/data-modeling

[1] https://www.edgedb.com/showcase/edgeql

Re: Ask HN: What could a modern database do that PostgreSQL and MySQL can't

#65

Post by alberth » Sun, Sep 05, 2021, 8:47 PM UTC

grobbie wrote: post #10

CockroachDB is getting a lot of interest these days. It has broad PGSQL language (and also wire I think) compatibility yet has a clustered peer architecture well suited to running in a dynamic environment like cloud or k8s. Nodes can join dynamically and it can survive them leaving dynamically as long as there's a quorum. Data is distributed across the nodes without administrator needing to make any shard rebalance t…

Sounds like Mnesia, which has existed for 20+ years.

https://erlang.org/doc/man/mnesia.html

Re: Ask HN: What could a modern database do that PostgreSQL and MySQL can't

#66

Post by masa331 » Sun, Sep 05, 2021, 8:50 PM UTC

This title kind of implies that PG or MySQL aren't modern or modern enough which i think is is very wrong. Look what they bring in every update. I think they are quite modern!

Re: Ask HN: What could a modern database do that PostgreSQL and MySQL can't

#67

Post by johnchristopher » Sun, Sep 05, 2021, 8:50 PM UTC

zz865 wrote: post #58

My biggest problem with databases is always versioning. IE renaming a column will break old clients. If there was a way you could have multiple schema versions so you could upgrade database then clients later it would be the best. EDIT: yes thanks for the comments, views and creating and API layers and adding instead of subtracting do all work, but I believe they're all workarounds for the underlying problem. Fixing…

Besides using an ORM that would hide the renaming or views, why not build an API layer ?

Re: Ask HN: What could a modern database do that PostgreSQL and MySQL can't

#68

Post by nicoburns » Sun, Sep 05, 2021, 8:51 PM UTC

spiffytech wrote: post #51

XCSme wrote: post #45

Earlier quoted context omitted.

Can't you add something like this to MySQL using triggers or some similar system?

Hasura evaluated Postgres' listen/notify feature to power their subscriptions, but chose polling instead: https://github.com/hasura/graphql-engine/blob/master/archite... > Listen/Notify: Requires instrumenting all tables with triggers, events consumed by consumer (the web-server) might be dropped in case of the consumer restarting or a network disruption. It was substantially non-trivial for them to implement subscri…

The Superbase (https://github.com/supabase/realtime) approach is really interesting. It listens to the logical replication stream. Makes a lot of sense to me. Unfortunately our postgres instances hosted on heroku don't expose this, so I've been unable to try it out.

Re: Ask HN: What could a modern database do that PostgreSQL and MySQL can't

#69

Post by rad_gruchalski » Sun, Sep 05, 2021, 8:54 PM UTC

alberth wrote: post #65

grobbie wrote: post #10

CockroachDB is getting a lot of interest these days. It has broad PGSQL language (and also wire I think) compatibility yet has a clustered peer architecture well suited to running in a dynamic environment like cloud or k8s. Nodes can join dynamically and it can survive them leaving dynamically as long as there's a quorum. Data is distributed across the nodes without administrator needing to make any shard rebalance t…

Sounds like Mnesia, which has existed for 20+ years. https://erlang.org/doc/man/mnesia.html

That’s a huge oversimplification. Mnesia is distributed but that’s about it. There’s so much more to sql than selecting data. Transactions, user defined functions, stored procedures, custom types…

Re: Ask HN: What could a modern database do that PostgreSQL and MySQL can't

#70

Post by CharlesW » Sun, Sep 05, 2021, 9:04 PM UTC

Upitor wrote: post #52

shekispeaks wrote: post #40

Automatic indexes. Adding indexes is a guessing game. It's a bit of abstraction leakage. Imagine a product engineer did not have to think about how the data is laid out on disk

What? I wouldn’t want this. How would you evne automate it? Creating the right indexes is the same as creating the right tables and columns in your data model: It depends on the business purpose and usage of the data.

> Creating the right indexes is the same as creating the right tables and columns in your data model: It depends on the business purpose and usage of the data.

Right, so the way this works is that the database collects instrumentation data and, over time, automatically applies strategies (indexing improvements being one of them) to improve its performance.

https://arxiv.org/abs/2007.14244