1. A computer-implemented query system having a physical storage media, comprising: a query plan for execution against data stores that include row data stores and column data stores; and a query execution component that controls execution of the query plan to switch between row-wise processing and column-wise processing based on the data stores accessed as part of query plan execution, row-wise processing including processing a plurality of rows one at a time and column-wise processing including processing another plurality of rows as one batch, the query execution component being configured to switch from row-wise processing to column-wise processing and the query execution component being configured to switch from column-wise processing to row-wise processing.