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

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91–100 of 326 posts

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

#91
I would be interested in more sophisticated type definitions. That is, algebraic data types.

One can achieve this to a degree by storing the data as JSON, but it would be nice to be able to remove the chance of introducing errors when converting to/from JSON.

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

#93

Subscriptions. Databases like Firebase will automatically push changes to query results down to clients. You can add this to Postgres with tools like Hasura, but it's poll based and not very efficient. It's a super-useful feature for keeping UIs in sync with database state.

Postgres has LISTEN and NOTIFY. People build DIY pub-sub with this.

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

#94

Relationships between tables, as supported by Microsoft Access.. it did cascaded deletes and things automagically. Persistent queries, where any change to the answer is propagated, like a subscription to a feed.

ON DELETE CASCADE has been in SQL since approximately forever.

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

#97

One thing PostgreSQL would likely not be able to adapt to, at least without significant effort, is dropping MVCC in favor of more traditional locking protocols. While MVCC is fashionable nowadays, and more or less every platform offers it at least as an option, my experience, and also opinions I have heard from people using SQL Server and similar platforms professionally, is that for true OLTP at least, good ol’ lock…

I don't know. Lock-based concurrency control has problem scaling up concurrent access among readers and writers for read consistency. Of course Oracle with MVCC still beats everybody performance wise.

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

#99

One thing PostgreSQL would likely not be able to adapt to, at least without significant effort, is dropping MVCC in favor of more traditional locking protocols. While MVCC is fashionable nowadays, and more or less every platform offers it at least as an option, my experience, and also opinions I have heard from people using SQL Server and similar platforms professionally, is that for true OLTP at least, good ol’ lock…

I sort of want the opposite. Except for extremely high velocity mutable data, why do we ever drop an old version of any record? I want the whole database to look more like git commits - completely immutable, versionable, every change attributable to a specific commit, connection, client, user.

So much complexity and stress and work at the moment comes from the fear of data loss or corruption. Schema updates, migrations, backups, all the distributed computing stuff where every node has to assume every other node could have mutated the data .... And then there are countless applications full of "history" type tables to reinstate audit trails for the mutable data. It's kind of ridiculous when you think about it.

It all made sense when storage was super expensive but these days all the counter measures we have to implement to deal with mutable state are far more expensive than just using more disk space.

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

#100
post #66

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!

The title seems fair to me. Anything that's actually used has certain commitments it made earlier in its lifecycle from which it now can't deviate, even if later developments made the commitments problematic.
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