Abstract: A data store system may include an array of persistent storage devices configured to store a plurality of data store tables. The data store system may further include a processor in communication with the storage device. The processor may receive a query containing a non-equality join condition on a first column from a first data store table and a second column on a second data store table. The processor may generate a bitmap based on the join condition. The bitmap indicate respective matches between the first column and second column in accordance with the non-equality join condition. The bitmap may also be used each time the non-equality join condition is present in another received query. A method and computer-readable medium may also be implemented.

Abstract: A database system may include a storage device to store a plurality of database tables. At least a portion of the database tables may be column-partitioned. The database system may also include a processor in communication with the storage device and a row-column subsystem executable by the processor to receive a request to locate a row of a column-partitioned database table. The row in the request may be used to provide a response to a query. The row-column subsystem may be further executable to determine if referenced column values of the requested row are stored in a cache associated with the row-column subsystem. The row-column subsystem may be further executable to retrieve the referenced column values of the row in the request from the cache in response to the determination that the column values are in the cache. The row-column subsystem may be further executable to provide the referenced column values for evaluation with respect to query conditions of the query.

Abstract: Deriving join cost demographics for a binary join, i.e., a join between two relations each having a join column, includes using a correlation factor related to the ratio of unique join column values stored in each of a plurality of units of storage to the total number of unique values in the join column.

Abstract: A database system is able to perform efficient execution of insert-select, join-delete, or join-update requests. The database system has plural access modules to manage access of respective portions of data in a storage of the database system. If certain predefined criteria are satisfied, the insert-select, join-delete, or join-update request can be executed by performing a single-access module merge and/or merge-delete step on a single one of the access modules with row-level locks (e.g., row-hash locks).