Missing features

[MMeent]

Lists of features that would be useful

Correctness

• VACUUM support

Performance

• Deduplicate vectors (like GIN & btree)
• Implement IVF-flat, with clusters stored in btrees, ordered by distance from centroid.
  This allows for prefetching & improved prioritization of candidate tuples)
• Store the index on disk
  The index shouldn't need time to rebuild every time the system restarts, and shouldn't consume memory if there is no-one to use the index.
  I hear that this is WIP.

Features

• More similarity/distance functions:
  • Manhattan/taxicab (L1) distance: Manhattan distance #9
  • Chebyshev (L-inf) distance
  • Cosine similarity