Abstract: A method for execution by a dispersed storage and task (DST) processing unit includes obtaining distributed storage and task network (DSTN) address range information for each memory device of a set of memory devices associated with a storage unit targeted for an upgrade; obtaining a list of slice names associated with selected slices stored in each memory device of the storage unit; retrieving the selected slices associated with the list of slice names; generating an integrity check value for the selected slices; storing one or more of: the integrity check value, the selected slices, or the list of slice names as original integrity information in a memory; and enabling an upgrade sequence of the DST execution unit.

Abstract: As part of a database system comprising a combination of on-disk storage and in-memory storage, a plurality of records that comprise a table are stored in a plurality of fragments that include at least a delta fragment and a main fragment retained in the on-disk storage. Each fragment has visibility data structures to enable multi-version concurrency control. Each fragment can be compressed using dictionary compression and n-bits compression. The fragments are loaded into main system memory in the in-memory storage from the on-disk storage if they are accessed for read operations or write operations and are not already in memory. A plurality of lockless read and write operations are concurrently performed, while providing snapshot isolation, on the at least one of the plurality of fragments while the at least one of the plurality of fragments is in the main system memory.

Abstract: A method in a computer system executing a client application and an OODBMS and an RDBMS software, which system has a storage medium accessible by the RDBMS software and the OODBMS software being accessible by the client application. The method generates unique object identifiers in a data abstraction layer disposed between the OODBMS and the RDBMS software in response to a parent thread created by the client application. The method includes the steps of creating a child thread that has access to the RDBMS software, which child thread is used exclusively for generating object identifier numbers and for returning the same to the parent thread. A unique object identifier table is created, which is maintained by the child thread. In response to a request by the parent thread for a unique object identifier, the child thread generates a finite number of the unique object identifiers and communicates their values to the parent thread.