Multiple-computer data processing system and method with time-versioned data storage
AssigneeFujitsu Services Limited
InventorPaul Anton Richardson Gardner
Life of this patent
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Abstract
A data processor comprises a number of databases for storing records and a plurality of user systems capable of accessing the databases. The user systems each include a datastore/application environment instance with which users can interface. Host systems may include more than one instance. The datastores contain time-versioned views of records. The data processor is operable in at least two modes, a normal operation mode in which an evaluation in response to a user enquiry can be carried out using records relevant to a current viewpoint time and time span, and a recovery operation mode in which records relevant to a viewpoint time and time span for a previous evaluation are accessed and used to exactly reproduce the previous evaluation.
Claims6
A data processing apparatus comprising:
- a plurality of user systems respectively including a plurality of object store instances, and at least one database accessible by said user systems, wherein the object store instances store time-versioned views of a plurality of objects as a plurality of records in said database, each of said records containing at least one attribute, a time span, a creation time, an object version marker, and a type field indicating whether said record is a concrete record or a delta record that modifies an attribute value of a previous record;
- separate clocks for each of the object store instances;
- means in each of the object store instances for performing an evaluation involving a particular object, relevant to a viewpoint time and time span;
- and
- means in each of the object store instances for employing a creation time of a most recent version of said particular object in a calculation to determine whether a time adjustment is required and whether said evaluation should be re-run in view of non-synchronization of the object store instances' clocks and clock-skew between the object store instances.
A data processing apparatus comprising:
- a plurality of user systems respectively including a plurality of object store instances, and at least one database accessible by said user systems, wherein the object store instances store time-versioned views of a plurality of objects as a plurality of records in said database, each of said records containing at least one attribute, a time span, a creation time, and a type field indicating whether said record is a concrete record or a delta record;
- means in each of the object store instances for accessing records relevant to a particular viewpoint time and time span;
- and
- recovery supporting means in each of the object store instances for storing a most recently used viewpoint time and time span together with a commit time as an instance of a session object, for linking the session object to an object identifying an object store instance, and for adding the session object to a relevant atomic unit.
A data processing method for use in a data processing system comprising at least one database and a plurality of user systems, the database being accessible by said user systems, and the user systems respectively including a plurality of object store instances having separate clocks, the method including:
- storing time-versioned views of a plurality of objects as a plurality of records in said database, each of said records containing at least one attribute, a time span, a creation time, an object version marker, and a type field indicating whether said record is a concrete record or a delta record that modifies an attribute value of a previous record;
- performing an evaluation involving a particular object, relevant to a viewpoint time and time span;
- and
- employing a creation time of a most recent version of said particular object in a calculation to determine whether a time adjustment is required and whether said evaluation should be re-run in view of non-synchronization of the object store instances' clocks and clock-skew between the object store instances.
A data processing method for use in a data processing system comprising at least one database and a plurality of user systems, the database being accessible by said user systems, and the user systems respectively including a plurality of object store instances, the method including:
- storing time-versioned views of a plurality of objects as a plurality of records in said database, each of said records containing at least one attribute, a time span, a creation time, and a type field indicating whether said record is a concrete record or a delta record;
- accessing records relevant to a particular viewpoint time and time span;
- and
- supporting recovery by storing a most recently used viewpoint time and time span together with a commit time as an instance of a session object, linking the session object to an object identifying a particular object store instance, and adding the session object to a relevant atomic unit.
Dependencies are inferred from the claim text.