Suppose you have an unsorted array of numeric values and need to find the set of indexes of all the values which are within a range. The range predicate will be evaluated many times, so any time spent preprocessing will be amortised, and non-zero spatial overhead is expected. If the data were sorted, this would be very easy, but the indexes of the values have meaning so the data cannot be sorted. To complicate the problem slightly, the set of indexes must be produced in sorted order.| Richard Startin’s Blog
I have just implemented support for (in)equality queries against a RangeBitmap, a succinct data structure in the RoaringBitmap library which supports range queries. RangeBitmap was designed to support range queries in Apache Pinot (more details here) but this enhancement would allow a range index to be used as a fallback for (in)equality queries in case nothing better is available. Supporting (in)equality queries allows a RangeBitmap to be used as a kind of compact inverted index, trading spa...| Richard Startin’s Blog
This post follows on from my last post about selecting objects satisfying a range predicate, and instead looks at how to count the objects. If you can select objects, you can count them too, but it’s a simpler problem so resources can be saved with a specialised solution.| Richard Startin’s Blog
Suppose you are doing some kind of data analysis in Java, perhaps you are analysing transactions (as in sales made). You have complex filters to evaluate before performing a calculation on Transaction objects.| Richard Startin’s Blog