Patent ID: 9292564
Filing Date: 2016-03-22
CPC Classification: G06F

Claim Text:
1. A method comprising: maintaining, on persistent storage, a database that is accessible to a database server; wherein the database includes a set of persistent format data (PF data), stored on the persistent storage, in a persistent format; converting the set of PF data to a mirror format to produce a set of mirror format data (MF data); storing the set of MF data within volatile memory; wherein the mirror format is different from and independent of the persistent format; wherein, within the volatile memory, the set of MF data is accessible to the database server; wherein each data item in the set of MF data is a copy of a corresponding data item in the set of PF data; within the volatile memory, the database server maintaining the set of MF data transactionally consistent with the set of PF data as the database server executes database operations that make changes to the set of PF data; receiving, by the database server, a request to execute a database command that requires both a first set of data items and a second set of data items; in response to receiving the request, the database server determining whether obtaining the first set of data items, for execution of the database command, from the set of PF data would be more efficient than obtaining the first set of data items, for execution of the database command, from the set of MF data; and during execution of the database command: