Method for logging update queries

1. A method of logging update queries in a computer media, comprising:

evaluating queries that have been queued since a prior cycle;

responsive to any pages needed for evaluation not in a buffer pool, reading at least one page comprising a PAGE_ID and a largest epoch sub-key;

executing the queued queries;

responsive to any queries executed over a horizontal partition involving writes or other updates to that partition, setting a Boolean dirty flag in a MANYCORE device's memory for each column that was updated;

after executing all outstanding queries for a particular epoch, recording in a log file all queries that are updates that were executed in that epoch, replacing any variables that are evaluated at runtime, with actual values they had at time of execution; and

signifying a commit to the log file and flushing the log file to stable storage.

2. The method of claim 1 , additionally comprising, at any time during the epoch, when a page of memory flagged as dirty is determined to require flushing to stable storage, writing a shadow copy of that page alongside a stable copy without overwriting an existing stable page of memory on disk.

3. The method of claim 2 , wherein the writing the shadow copy comprises writing the shadow copy using a filename comprising a value of PAGE_ID appended with the epoch sub-key of epoch+1.

4. The method of claim 2 , additionally comprising, at any time during a cycle after all queries are evaluated for that cycle at periodic or occasional checkpoints:

executing the following steps in sequential order:

(i) flushing to disk all dirty pages in the buffer pool;

(ii) incrementing an epoch counter; and

(iii) flushing a value of the epoch counter to stable storage; and

identifying a beginning of a new epoch.