Storage format for encoded vector indexes

Abstract

A storage format and methods for improving the performance of the symbol table of an encoded vector index. The symbol table comprises a hash table, entries of the hash table storing associated key values and codes for the encoded vector index. Hash table entries store an accumulated count of occurrences of prior and the current key values, which improves the efficiency of responding to a request for a key range count. A binary radix tree is used to locate entries, which comprises a plurality of nodes, corresponding to binary digits of a binary representation of a key value. Codes are assigned to key values for the encoded vector index in a distributed fashion, so there are available code values between existing code values in the code ordering, that can be assigned to new key values, alleviating the need to reorganize the code values upon an insertion.