US Patent 11989185 In-memory efficient multistep search

A cascading search system includes an associative memory array, a similarity match processor and an exact match processor. The columns of the array store a plurality of multiportion data vectors and have a first section, for a first portion of a vector, a second section for storing a second portion of a vector and a match row. The similarity match processor performs a parallel similarity search of a similarity query in the first sections and stores a match bit indication in the match row of the column. Each match bit indication indicates if its column has a first portion which matches the similarity query. The exact match processor performs an exact search in parallel in the second section of each similarity matched column whose match bit indication indicates a match of its first section and outputs those similarity matched columns whose second portions match the exact query.