System and method for aggregating query results in a fault-tolerant database management system

A method for a storage system including a plurality of storage nodes and storing a plurality of content data, and a plurality of original metadata and back-up metadata associated with the plurality of content data, the method comprising:

• managing, by each of the plurality of storage nodes, a first storage region storing one or more original metadata of the plurality of original metadata, and a second storage region storing one or more back-up metadata of the plurality of back-up metadata;
• executing, by each of the plurality of storage nodes, search on its own first storage region, without search on its own second storage region, for content data and/or metadata related to a query;
• and
• aggregating, by one of the storage nodes, results of the search sent from other storage nodes, to respond to the query.

A storage system storing a plurality of content data, and a plurality of original metadata and back-up metadata associated with the plurality of content data, the storage system comprising:

• a plurality of storage nodes, each of which includes a processor being configured to manage a first storage region storing one or more original metadata of the plurality of original metadata, and a second storage region storing one or more back-up metadata of the plurality of back-up metadata;
• and
• a network being configured to couple the plurality of storage nodes with each other;
• wherein the processor of each of the plurality of storage nodes is configured to search its own storage region, without searching its own second storage region, for content data and/or metadata related to a query, and provide result of the query to one of the storage nodes, and
• wherein the processor in the one of the storage nodes is further configured to aggregate the result sent from other storage nodes.