Abstract: Each of a plurality of data items is stored in a table data structure. The table structure includes a plurality of columns. Each of the columns is associated with one of a plurality of locality groups. Each locality group is stored as one or more corresponding locality group files that include the data items in the columns associated with the respective locality group. In some embodiments, the columns of the table data structure may be grouped into groups of columns and each group of columns is associated with one of a plurality of locality groups. Each locality group is stored as one or more corresponding locality group files that include the data items in the group of columns associated with the respective locality group.

Abstract: When searching a document database in response to a search query, a determination is made as to whether a query result corresponding to the search query is stored in a cache. When the query result is stored in the cache, a reuse count for the search query is accessed. When predefined conditions are satisfied, such as the reuse count being larger than a predetermined threshold count, an improved search result is generated in accordance with a first set of predetermined searching criteria, and at least a subset of the improved search result is returned.

Abstract: Each of a plurality of data items is stored in a table data structure. A row identifier and column identifier are associated with each respective data item, and each respective item is stored at a logical location in the table data structure specified by its row identifier and column identifier. A plurality of data items is stored in a cell of the table data structure, and a timestamp is associated with each of the plurality of data items stored in the cell. Each of the data items stored in the cell has the same row identifier, the same column identifier, and a distinct timestamp. In some embodiments, each row identifier is a string of arbitrary length and arbitrary value. Similarly, in some embodiments each column identifier is a string of arbitrary length and arbitrary value.

Abstract: When a search query is received, a plurality of partition indexes are searched using the set of search terms in the search query. Each partition index corresponds to a partition of a document index. The search of each respective partition index identifies a subset of a plurality of document index sub-partitions corresponding to the respective partition index. Next, the search query is executed by only those document index sub-partitions identified by the subsets, thereby identifying documents that satisfy the search query. By using the partition index to reduce the number of document index sub-partitions searched while executing a search query, the execution of the search query is made more efficient.

Abstract: Once a search query is received from a user, a standard index is searched based on the search query. The standard index forms part of a set of replicated standard indexes having multiple instances of the standard index. A signal is then determined based on the search of the standard index. When the received signal meets predefined criteria, an extended index is searched. The extended index forms part of a set of extended indexes having at least one instance of the extended index. There are fewer instances of the extended index than instances of the standard index. Extended search results are then obtained from the extended index and at least a portion of the extended search results is transmitted towards a user.