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.
Patent No.:
Date of Patent:
May. 06, 2003
Filed:
Jun. 30, 1999
Douglas S. Boa, Redmond, WA (US);
Simon M. Meacham, Redmond, WA (US);
Barry M. Nolte, Kirkland, WA (US);
Microsoft Corporation, Redmond, WA (US);
Abstract
A method, apparatus, software and data structure is disclosed for more efficient access times for linear operations in a hash table. A plurality of actual data records and a plurality of marker data records are inserted in a hash table using a hash function. The actual data records and marker data records have a logical ordering specified by a key and are threaded into the hash table to allow linear access by walking the hash table. The logical ordering of the actual data records and marker records is lost upon entry into the hash table, and the keys of the marker data records are distributed at known positions throughout the range of the keys of the actual data records. If when hashing a given key no record exists in the database for the given key, one of the keys for the marker data records are hashed to locate the associated marker data record in the hash table. Distribution of data records according to the hash function is also determined by locating a marker data record in the database and examining the position of adjacent records. The distribution of records provides a measure of performance of the hash table and for tuning of the hash table.