High cardinality Bitmap indexes

[slimdave]

I remember that 8.1.7.4 issue. Ah, happy days.

Long story short, dml ops that modify bitmap indexes are a bitch in any version, and i wouldn't trust the resulting index. It's not really an issue for the environmenti work in anymore because we disable the indexes before inserting new data, then rebuild them afterwards. sure is faster than inserting into a bitmap.

As for the cardinality issue, you're probably on the borderline of bitmap and btree, especially if you implement compression on the btree index. benchmarking is the way to go there, comparing index size and performance.

Have you implemented any physical row ordering, by the way? that really cuts down on bitmap index size.


[edited to insert spaces. i have toast crumbs stuck under my space key]