search

timescale / timescaledb

An open-source time-series SQL database optimized for fast ingest and complex queries. Packaged as a PostgreSQL extension.
https://www.timescale.com/
Other
17.43k stars 873 forks source link

[Enhancement]: Remove support for partials in continuous aggregates #4959

Open mkindahl opened 1 year ago

mkindahl commented 1 year ago

What type of enhancement is this?

Tech debt reduction

What subsystems and features will be improved?

Continuous aggregate

What does the enhancement do?

Fully remove the support for partials in continuous aggregates.

Implementation challenges

The code for supporting partials need to be remove as well as some manner to block upgrades to this version if you have partials.

tucnak commented 1 year ago

Does this mean that continuous aggregates in 3.0.0 won't do partial materialisations? Why is that so? I thought one of the more attractive propositions in favour of caggs were that if you're able to materialise partials, you don't have to re-run the complete aggregation but simply pick the state as it were left off, see two-step aggregation, et cetera. If these were to be removed, that would significantly reduce the leeway for custom aggregates that are kind of necessary if you want to perform the type of aggregations that would otherwise require a subquery, a CTE, or a JOIN.