Well, the most important wishes I have for 2018 are a bit out of topic for this blog: forms of organisation without a formal authority, schools not teaching religions, and so on. But in this post, I will write about databases… as usual.

So, here is my whishlist, for what it matters.

More research on Learned Indexes

If you don’t know what I’m talking about, see this paper. Having a data structure faster than B-Trees is exciting. But of course I’d like to see also considerations on write performance.

Progress on using ML for database tuning

See this article. I don’t think that Machine Learning will ever be able to replace (good) DBAs, but having a tool which suggests tuning based on real workload sounds great. It can be a valid help for DBAs.

More research on stored functions transformation

Stored functions are useful but slow. But see this paper. It seems it is possible to transform imperative programs to queries, improving the complexity by some orders of magnitude.

On a side note, MariaDB implemented a lot of syntax from Oracle for stored procedures. While this sounds like a precise commercial strategy, the technical improvement on this area is great. Still, what I’d like to see is better performance, as well as support for external languages.

Galera 4

Let me be clear, I didn’t read any announcement that Galera 4 will be released this year. But they announced exciting news over time, and still the new version isn’t here. At some point, it should be released (hopefully).

Transactional DDL in the MySQL ecosystem

MySQL 8.0 has support for atomic DDL statements. They did it in a good way: it’s engine independent and, while it uses InnoDB information_schema tables, any engine is free to add support for this feature. They stated that this is the basis for transactional DDL, but we are not yet there. MariaDB has a task for transactional DDL.

EDIT: Thanks to Valerii Kravchuk for pointing me MDEV-11424 – Instant ALTER TABLE of failure-free record format changes. It is clearly worth adding it to my wishlist: please Maria, get it done!

Engines, engines, engines

RocksDB is great, please consolidate it. TokuDB can improve in many ways, please don’t stop investing on it. Next version of SPIDER will be in MariaDB 10.3, I hope that the development will be a bit more active in the future.

Don’t kill MyISAM. It is still useful in some cases. For Catawiki use cases, I find it better than InnoDB for temporary tables. Also JFG has a great use case example.

More progress on Tarantool and CockroachDB

Tarantool is a great database, originally NoSQL. It is extremely scriptable (actually it can be seen as a Lua application server) and its modules allow to read and write data from a wide variety of data sources, including MySQL replication. Recently, SQL support has been added.

CockroachDB is an open source RDBMS design to scale geographically. It uses distributed transaction. It also allows to tune the redundancy of data at table level and define replication zones.

Great conferences

I will be both at M18 (I’m not sponsored by my company, but I chosen to go anyway) and Percona Live. At M18 I will give a talk titled Somewhere between schema and schemaless. Of course I also submitted proposal for Percona Live, let’s see if they get accepted.