Fault-tolerant database query execution plans using non-volatile memories

A non-transitory computer-readable storage medium coupled to one or more processors and having instructions stored thereon which, when executed by the one or more processors, cause the one or more processors to perform operations comprising:

• receiving a query;
• retrieving an annotated query execution plan (QEP) that is associated with the query, the annotated QEP comprising a plurality of operators in respective lines, which are executed to provide a query result, at least one line having annotations for check-pointing an intermediate result provided by a respective operator;
• and
• determining that a power failure occurred during execution of the annotated QEP in an in-memory database system, and in response:
• determining that a checkpoint for the at least one line is stored in non-volatile memory (NVM),
• retrieving the intermediate result provided by the respective operator from the NVM, and
• restarting execution of the annotated QEP using the intermediate result as input to an operator provided in a line following the at least one line.

A system, comprising:

• a computing device;
• and
• a computer-readable storage device coupled to the computing device and having instructions stored thereon which, when executed by the computing device, cause the computing device to perform operations comprising:
• receiving a query;
• retrieving an annotated query execution plan (QEP) that is associated with the query, the annotated QEP comprising a plurality of operators in respective lines, which are executed to provide a query result, at least one line having annotations for check-pointing an intermediate result provided by a respective operator;
• and
• determining that a power failure occurred during execution of the annotated QEP in an in-memory database system, and in response:
• determining that a checkpoint for the at least one line is stored in non-volatile memory (NVM),
• retrieving the intermediate result provided by the respective operator from the NVM, and
• restarting execution of the annotated QEP using the intermediate result as input to an operator provided in a line following the at least one line.