The Query Your Database Can’t Answer

by mjdrogalison 6/4/2021, 3:02 PMwith 10 comments

by Animatson 6/4/2021, 4:29 PM

Ad.

Some years ago, Microsoft was working on that. The idea was that you'd submit a query, and when the results of it changed, you'd get a notification. The goal was to have a large system where millions of such outstanding queries could be pending.

What this really means is a database of queries, which is queried when there's a data update to see who needs to be informed.

Anyone know how that Microsoft project came out?

by georgewfraseron 6/4/2021, 5:11 PM

Anyone thinking about using Confluent as some kind of alternative to a database should read this blog post outlining the myriad correctness problems with ksqlDB: https://scattered-thoughts.net/writing/internal-consistency-...

by ttzon 6/4/2021, 4:56 PM

Am I misreading something here?

> Namely, you can’t write a query whose result updates every time the underlying data change

Yeah, you can. With triggers. Or just a plain old view.

by tantaloron 6/4/2021, 5:28 PM

> a query whose result updates every time the underlying data changes

Isn't this exactly what spreadsheet programs like VisiCalc have done since the 1980s?

by lmilcinon 6/4/2021, 4:42 PM

This is basis for event stream processing systems which nicely supplement database systems. Actually, event stream processing is just inversion of database concept:

In a database you have data to which you direct queries.

In event stream processing you have collection of queries to which you direct data.

by opwieurposiuon 6/4/2021, 5:00 PM

Anyone know the price of Confluent's control center product?