Abstract: The databases and methods disclosed herein reduce costly dictionary access (writes and reads) by storing data directly in an index (e.g., storing literal values or taking advantage of Universally Unique Identifiers (UUIDs)), thereby saving time and memory. One example embodiment is a database that includes a dictionary and an index. The dictionary stores associations between keys and data. Each entry in the index includes a plurality of values corresponding to data. A value of the index includes either (i) a direct representation of corresponding data for certain data types, or (ii) a hash of the corresponding data for other data types. The hash is used in the dictionary as a key associated with the corresponding data.

Abstract: The databases and methods disclosed herein reduce costly dictionary access (writes and reads) by storing data directly in an index (e.g., storing literal values or taking advantage of Universally Unique Identifiers (UUIDs)), thereby saving time and memory. One example embodiment is a database that includes a dictionary and an index. The dictionary stores associations between keys and data. Each entry in the index includes a plurality of values corresponding to data. A value of the index includes either (i) a direct representation of corresponding data for certain data types, or (ii) a hash of the corresponding data for other data types. The hash is used in the dictionary as a key associated with the corresponding data.

Abstract: A method and corresponding system upgrades a live computer system. The method begins with migrating a copy of data from a first system to a communicatively coupled second system at a first time. Next, at one or more subsequent times, a copy of changed data is migrated from the first system to the second system until a threshold is reached. Finally, in response to reaching the threshold, a copy of the remaining changed data is migrated from the first system to the second system. A further embodiment of the method comprises: disabling access to the first system during the migration of data at the first time, enabling and maintaining access to the first system at the one or more subsequent times during the migration of the copy of changed data, and disabling access to the first system during the migration of the copy of the remaining changed data. In this manner, the system being upgraded is still highly available throughout the upgrade process.

Abstract: A method and corresponding system upgrades a live computer system. The method begins with migrating a copy of data from a first system to a communicatively coupled second system at a first time. Next, at one or more subsequent times, a copy of changed data is migrated from the first system to the second system until a threshold is reached. Finally, in response to reaching the threshold, a copy of the remaining changed data is migrated from the first system to the second system. A further embodiment of the method comprises: disabling access to the first system during the migration of data at the first time, enabling and maintaining access to the first system at the one or more subsequent times during the migration of the copy of changed data, and disabling access to the first system during the migration of the copy of the remaining changed data. In this manner, the system being upgraded is still highly available throughout the upgrade process.