Fault tolerant update propagation to views

A method of committing to storage updates to derived data, comprising:

• receiving a view data element to be written to an identified derived data view;
• receiving a signature associated with the data element, the signature uniquely indicative of a base table record, a view table of which the view data element is a part, and sequence information relating to one or more of a number of times that the base table record was updated and a view sequence number;
• initiating a process of committing the view data element to storage, the process including comparing the signature with signatures previously received for other view data elements;
• and
• rejecting the view data element as being repetitive if the signature matches with any previously received signature.

A computer readable medium storing computer readable code for a method of propagating updates to base data into derived data, comprising:

• specifying one or more non-idempotent updates to records of one or more view tables, each view table associated with distinct identifier information, each update based on one or more records from one or more base tables, each base table associated with distinct identifier information, and each record associated with respective base record sequence numbers indicative of a number of times that base record has been updated;
• for each of the updates to one or more view tables that are for the same view table, providing an index allowing discrimination between each update to the same view table;
• and
• recovering from an operational excursion by using the view table identifier information, the base table identifier information, the base record sequence numbers and the numbers associated with view table records in determining whether each view table record update was committed to view table storage based on comparisons with similar information known to correspond with committed view table record updates.

A database system with base data tables and view data tables derived from the base data tables, comprising:

• a first database resource storing a plurality of base tables;
• a second database resource storing a plurality of view tables derived from data in the base tables, and configured for changing the view tables responsively to receiving view table updates and generating a respective change confirmation for each view table update for which a change was committed to the view tables;
• and
• a view manager operable for receiving indications of updates to the base tables, for determining updates to be made to the view tables based on the updates to the base tables, for submitting the view table updates to the second database resource, and for generating a respective identifier for each non-idempotent view table update, and for responding to an operational excursion by resubmitting to the second database resource any view table update and its corresponding signature for which a commitment confirmation was not received by the view manager prior to the failure,
• wherein the identifier comprises information identifying a base table whose update caused the view table update, the respective view table, and update sequence information for the respective view table, and
• wherein the second database resource is operable to use the identifiers for determining which resubmitted view table updates correspond to base table updates already comprehended in the view tables, and reject such view table updates.

A method for use in updating derived data in database systems, comprising:

• receiving base table information to be used as a basis for producing an update to an element of derived data;
• using the base table information in producing the update;
• producing identifier information for association with the update, the identifier information having characteristics including uniquely identifying the element of base data from among a plurality of base data elements, uniquely identifying the element of derived data to which the update pertains, and sequence information;
• communicating the identifier information and update to a system for committing the update;
• and
• recovering from an operational excursion by using the identifier information in determining whether derived data updates for the base table information were committed before the failure condition.