Versioned insert only hash table for in-memory columnar stores

Abstract

At least one read operation is concurrently performed with at least one write operation that each insert a key/value pair into a backing array of a backing hash table of a hash table forming part of a columnar in-memory database. The backing array maps a plurality of pointers each to a respective bucket. Each bucket includes at least one state bit and a hashed value of a corresponding key. Thereafter, for each write operation, a first available position in the backing array at which a pointer to a new bucket containing the key/value pair can be inserted is iteratively determined (such that each first available position has no corresponding pre-existing pointer). Subsequently, for each write operation, the pointer to the new bucket containing the key/value pair is inserted at the corresponding first determined position in the backing array. Related apparatus, systems, techniques and articles are also described.