Abstract: Data structures can provide for a column store of a database table. Methods can use the data structures for efficiently responding to a query. Unique field values of a column of a database table can be identified. The unique values can be stored in a dictionary table along with reference keys that point to a row of the database table. A reference store column can replace the original column, where the reference store column stores index values of the dictionary table. A hash table can be used in accessing the database. A hash function can provide a hash value of a query term, and the hash value can be used to access a hash table to obtain a stored value of an index value of the dictionary table. The index value can be used to access the dictionary table to obtain reference keys corresponding to rows of the database table.

Abstract: Techniques to process a query and perform a join of tables that are distributed across nodes of a network. The join can be performed by analyzing a Where clause. An active flag structure can have flag values that identify table entries satisfying criteria of the Where clause. Keys of surviving entries of a first table can be used to generate a request for a second table to be joined. The request can be for second flags for the second table when the Where clause has criteria for the second table. A response can be used to update the first flags to change a first flag to False. After updating, data can be retrieved for first flags that are True. Requests can use identifiers associated with the first table that identify a location for sending the request, e.g., using RDMA or MPI.