Patent ID: 7113795

Claim:
In a distributed database system having n database servers, D 1 , . . . , D n , arranged in a logical ring, a method of updating k of the database servers, D γ1 , . . . , D γk , referred to by a placement vector Γ=(γ 1 , . . . , γ k ), wherein γi ε{1, . . . , n} is the index of the ith database server updated by the method, the method comprising: selecting γ 1 from the set (1, . . . , n); for i=1, . . . , k−1, selecting γ i+1 according to γ i ⊕└n/k┘+a i , wherein: ⊕ is modulo addition defined over the set (1, 2, . . . , n); displacement vector â=(a 1 , . . . , a k ) is a binary vector having a Hamming weight of β; and β=n−└n/k┘*k; and updating the k database servers, D γ1 , . . . , D γk , referred to by the placement vector Γ=(γ 1 , . . . , γ k ), with updated information.