#ReleaseDay https://thi.ng/column-store is an in-memory database with customizable column types, extensible query engine, bitfield indexing for query acceleration, JSON serialization with optional RLE compression.

The new version introduces support for arbitrarily nested queries and merging of sub-query results using a choice of AND (intersection/constraint), OR (union/alternative) or NAND/NOR (negated versions) semantics.

https://docs.thi.ng/umbrella/column-store/#nested-queries

Also without query nesting, each individual query term's results can be merged as union now. The previous behavior only allowed for term result intersections, with each subsequent term further narrowing the total result set. This behavior limited the types of compound queries possible and therefore required multiple separate queries and additional user effort to merge results manually. Well, no more! :)

https://docs.thi.ng/umbrella/column-store/#term-union

Another (intentional) side effect: Since queries are defined declaratively, creating complex queries is much easier (and legible) now via composition and re-use of predefined sub-queries. The support for nesting also simplifies the creation of user-defined query DSLs (domain specific languages).

As before, for columns with bitmap indexing enabled, most of the query operators are extremely fast since only bit masks need to be combined and no actual row or column data is being visited. The latter is only necessary for predicate-based matchXXX() operators...

#ThingUmbrella #OpenSource #Database #QueryEngine #TypeScript #BitField