The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
May. 23, 2017

Filed:

Jun. 03, 2013
Applicant:

Google Inc., Mountain View, CA (US);

Inventors:

Yasushi Saito, Mountain View, CA (US);

Sanjay Ghemawat, Mountain View, CA (US);

Sebastian Kanthak, San Jose, CA (US);

Christopher Cunningham Frost, Sunnyvale, CA (US);

Assignee:

GOOGLE INC., Mountain View, CA (US);

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G06F 7/00 (2006.01); G06F 17/00 (2006.01); G06F 17/30 (2006.01);
U.S. Cl.
CPC ...
G06F 17/30289 (2013.01); G06F 17/30067 (2013.01); G06F 17/30575 (2013.01);
Abstract

A computer system issues a batch read operation to a tablet in a first replication group in a distributed database and obtains a most recent version of data items in the tablet that have a timestamp no great than a snapshot timestamp T. For each data item in the one tablet, the computer system determines whether the data item has a move-in timestamp less than or equal to the snapshot timestamp T, which is less than a move-out timestamp, and whether the data item has a creation timestamp less than the snapshot timestamp T, which is less than or equal to a deletion timestamp. If the determination is true, the computer system determines whether the move-out timestamp has an actual associated value and, if so, the computer system determines a second tablet in a second replication group in the database that includes the data item and issues the snapshot read operation to the second table in the second replication group to obtain a most-recent version of the data item that has a timestamp no greater than the snapshot timestamp T; otherwise, the computer system issues the snapshot read to the one tablet to obtain a most recent version of the data item that has a timestamp no greater than the snapshot timestamp T.


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