1. A computer system for partitioning data for a query operation of one table of the database system, including a first table, based on attributes of a first column of the first table, the query operation resulting in a result table for partitioning input tables of the first table, the computer system comprising: one or more processors, one or more computer-readable memories, one or more computer-readable tangible storage devices and program instructions which are stored on at least one of the one or more storage devices for execution by at least one of the one or more processors via at least one of the one or more memories, the program instructions comprising: program instruction to estimate a value distribution of an attribute in the result table based on a first value distribution of the attribute in the first column of the first table, wherein the step of estimating the value distribution of the attribute in the result table is based on the first value distribution of the attribute in the first column and on a second value distribution of the attribute in the second column, and wherein the first value distribution represents spread of data within the first column and the second value represents the second column; program instruction to determine boundaries for partitioning ranges of the attribute, based on the estimated value distribution, wherein the partitioning ranges correspond to a same number of rows of the result table, wherein the rows of the result table are estimated based on value distributions of a density distribution function, wherein a first value distribution and the density distribution are representing a spread of data within a first data column and a second value distribution density function and, wherein the second value distribution function represents a spread of data within a second data column; program instruction to determine assignment of particular partitioning ranges for processing units of the query operation, based on value distribution of the first column, stored on processing units of the query operation, based on minimization of data movement between processing units of the database system; and program instructions to partition the first table with processing nodes of the query operation, based on the determined boundaries of partitioning ranges.