Edouard P Duvillier

20020103814, Aug 1, 2002

Dec 12, 2000

09/736037

Edouard Duvillier - Sunnyvale CA, US
Didier Cabannes - Foster City CA, US

G06F017/30

707/202000

A technique for recoving a database having intrinsic versioning and no logging mechanism is described. The process allows the information storage and retrieval system to recover from crashes in very short times irrespective of the size and complexity of the data objects contained in the database. The recovery process does not require an update or transaction log, consequently all the delays associated with keeping a log, such write time to a log and log truncation during recovery are avoided. The most recent stable object table in the database is identified in a non-persistent memory storage area. An allocation map is then used to identify unstable data in the non-persistent memory area. The unstable data is then scanned to build a post-recovery object table. By performing this scan before a database crash or failure, a recovery can be performed without having to scan the non-persistent or the persistent memory areas of the information storage and retrieval system. In addition, a conventional transactional log file need not be maintained for the database to recover.

20020103815, Aug 1, 2002

Dec 12, 2000

09/736038

Edouard Duvillier - Sunnyvale CA, US
Didier Cabannes - Foster City CA, US

Fresher Information Corporation

G06F012/00

707/203000

A process for performing a transaction, such as a write operation, on a data object in a non-log based database is described. An information storage and retrieval system described can execute a transaction at a speed limited only by the hardware of the system. Updates to the data are done in sequential block writes which allow the data to be written continually to memory. This allows for real-time feed of large blocks of data, such as Web content of all types, into the database. The process described allows for handling large data updates in the same manner as small data updates. An entry for a data object containing version data for the data object is created and maintained in an object table. This entry for the data object is written or saved to a non-persistent memory, such as a cache memory at a particular non-persistent memory address. This write operation is then committed by saving the data object in a persistent memory area at a persistent memory area address. With respect to this write transaction, at least one inconsistent data page is identified in the non-persistent memory. This inconsistent data page is then written to the persistent memory area.

20020103819, Aug 1, 2002

Dec 12, 2000

09/735819

Edouard Duvillier - Sunnyvale CA, US
Didier Cabannes - Foster City CA, US

Fresher Information Corporation

G06F012/00

707/206000

A technique for stabilizing and collecting data in an information storage and retrieval system, referred to as checkpointing, is described. Checkpointing is used to increase the speed of the database during a recovery by only scanning data that the information storage and retrieval system knows is unstable, instead of scanning all the data in the database. Data that is deemed collectable, such as old data or obsolete data, is identified in a non-persistent memory space, such as a cache memory. A data page contained in an initial or first buffer is stored, also in the form of a data page, to a persistent memory type, such as a hard drive or virtual memory. Next, non-collectable data, or data that is to be maintained, in the initial or first buffer is identified. This data is stored in a second buffer. It is then determined whether the non-collectable data is referenced in an object table in the information storage and retrieval system. A first checkpoint flag field in an allocation map in the non-persistent memory area is set. Once the checkpoint flag field is set, the second buffer is flushed to the non-persistent memory type.

20020073082, Jun 13, 2002

Nov 20, 2001

09/990524

Edouard Duvillier - Mountain View CA, US
Didier Cabannes - Burlingame CA, US

G06F007/00

707/003000

A technique is disclosed for implementing system modification operations in an information storage and retrieval system. The information storage and retrieval system includes persistent memory configured or designed to store object data. The persistent memory includes at least one data file for storing object data. A first system modification request relating to a first data file is received, the first data file including a first object stored therein. The first system modification request is then implemented. According to a specific embodiment, the implementation of the first system modification request includes suspending write access to the first data file. Concurrently, while the first system modification request is being implemented, updated information relating to the first object may be stored in the persistent memory. According to a specific embodiment, the information storage and retrieval system corresponds to a non-positional, non-log based information storage and retrieval system. According to different embodiments, the information storage and retrieval system of the present invention may be configured to handle a variety of different system modification requests, including, for example, a request to add a mirror data file to be associated with a primary data file, a request to take the primary data file off-line, a request to take the mirror data file off-line. Moreover, according to a specific implementation, the implementing of the first system modification request may performed in real-time, without blocking access to object data stored in the persistent memory.

20020073110, Jun 13, 2002

Oct 12, 2001

09/976864

Edouard Duvillier - Sunnyvale CA, US
Didier Cabannes - Burlingame CA, US

G06F012/00

707/206000

A technique is disclosed for implementing collection of obsolete object versions stored in an information storage and retrieval system. The information storage and retrieval system includes persistent memory configured or designed to store a plurality of different object versions. The information storage and retrieval system further includes volatile memory which may be configured to store an object table which includes object version information relating to the plurality of object versions. The object version information includes information relating to locations in the persistent memory where each of the plurality of object versions are stored. A version collection procedure is initiated. At least one object version may then be identified as an obsolete object version without performing a memory access operation to the persistent memory to retrieve information relating to the at least one object version. In one embodiment, the identification of the obsolete object version may be accomplished using information contained in the object table. Further according to specific embodiments, the information storage and retrieval system may correspond to a non-log based information storage and retrieval system which is configured or designed to implement intrinsic versioning of objects stored within the system.