1. A distributed storage system comprising: a plurality of Key-Value Store Nodes (KVS-Nodes) organized into two layers of a first layer and a second layer each forming a logical ring, in which a successor node of the plurality of KVS-Nodes succeeds a predecessor node of the plurality of KVS-Nodes in the logical ring in case of failure, wherein each of the plurality of KVS-Nodes includes a processor, a network interface, a storage management module, and a storage interface, wherein the storage management module stores a first table in which data is stored in a column oriented layout scheme and distributed based on a hash value of column name in the first layer, or a second table in which data is stored in a row oriented layout scheme and distributed based on a hash value of row key in the second layer; wherein a KVS-node changes table orientation layout scheme from a column oriented layout scheme to a row oriented layout scheme, or from a row oriented layout scheme to a column oriented layout scheme, based on user access pattern of read/write access to the table having the table orientation layout scheme being changed; wherein the user access pattern is derived from user access history information relating to read accesses and write accesses to the table having the table orientation layout scheme being changed; wherein the user access pattern is represented by a read/write ratio of a number of the read accesses to a number of the write accesses; and wherein the KVS-node changes table orientation layout scheme from the row oriented layout scheme to the column oriented layout scheme if the read/write ratio is larger than a predefined first threshold, and from the column oriented layout scheme to the row oriented layout scheme if the read/write ratio is smaller than a predefined second threshold.