Abstract: A system identifies a performance bottleneck status in a parallel data processing environment by examining data flow associated with the parallel data processing environment to identify at least one operator, where an operator type is associated with at least one operator, at least one buffer, and a relationship that the buffer has with the operator, where the relationship is associated with the operator type. The system monitors the buffer to determine a buffer status associated with the buffer. The system applies a set of rules to identify an operator bottleneck status associated with the operator. The set of rules is applied to the operator, based on the operator type, the buffer status, and relationship that the buffer has with the operator. The system then determines a performance bottleneck status associated with the parallel data processing environment, based on the operator bottleneck status.

Abstract: Processing a database table comprises receiving a multi-dimensional processing instruction for processing at least two columns of the database table, wherein the two columns comprise a selection column and a sort column, wherein the multi-dimensional processing instruction is for selecting a plurality of candidate rows by sorting based on the selection column and the sort column. An index takes the selection column as master column and the sort column as slave column. Nodes in the index are selected according to the selection column. Each of the selected nodes is associated with a respective slave column value sequence. A merge sort is performed on each of the slave column value sequences to obtain a sort result for the candidate rows.

Abstract: A data driven parallel sorting method includes distributing input data records to n partitions one by one in a circular manner. Each partition corresponds to a parallel sorting process with an allocated memory chunk sized to store m data records. The method also includes sorting, in parallel, current data records in respective memory chunks in respective partitions. The method also includes in response to distribution of data records of ?m/n? rounds, circularly controlling one of the n partitions, and writing data records that have been sorted in the memory chunk of the partition into a mass storage as an ordered data chunk, and emptying the memory chunk. The method also includes in response to all data records being distributed, writing data chunks that have been sorted in respective memory chunks into the mass storage, and performing a merge sort on all ordered data chunks in the mass storage.