12. An apparatus, comprising at least one processor coupled to at least one machine-readable storage medium storing instructions executable by the at least one processor to implement: a compiler component configured to: receive a data query command tree from a data consumer; transform the data query command tree into a lower-level command tree expressed in data provider terms by leveraging an expression library of a query language that facilitates describing a result shaping function, wherein alternative versions of compiled functions for result shaping are maintained; produce reassembly information that includes column map instructions indicating how to group columns and how to group rows; and compile a set of expressions including stateless functions usable in a cache without recompilation; a store command generator component configured to: construct at least one store command definition corresponding to the lower-level command tree; a command execution component configured to: produce at least one store data reader based on the at least one store command definition; and a results assembly component configured to: apply the reassembly information to an output of the at least one store data reader to produce a data reader corresponding to the data query command tree from the data consumer.
12. An apparatus, comprising at least one processor coupled to at least one machine-readable storage medium storing instructions executable by the at least one processor to implement: a compiler component configured to: receive a data query command tree from a data consumer; transform the data query command tree into a lower-level command tree expressed in data provider terms by leveraging an expression library of a query language that facilitates describing a result shaping function, wherein alternative versions of compiled functions for result shaping are maintained; produce reassembly information that includes column map instructions indicating how to group columns and how to group rows; and compile a set of expressions including stateless functions usable in a cache without recompilation; a store command generator component configured to: construct at least one store command definition corresponding to the lower-level command tree; a command execution component configured to: produce at least one store data reader based on the at least one store command definition; and a results assembly component configured to: apply the reassembly information to an output of the at least one store data reader to produce a data reader corresponding to the data query command tree from the data consumer. 13. The apparatus of claim 12 , further comprising a component configured to remove sub-expressions for error handling from an expression to enhance performance, and substitute an expression with included error handling sub-expressions in response to receiving a compiler error.