Offloading projection of fixed and variable length database columns

A computer-implemented method, comprising:

• determining that a database query warrants a first projection operation to project a plurality of input rows to a plurality of projected rows, wherein each of the plurality of input rows has one or more variable-length columns;
• constructing, by a computer processor, a first projection control block to describe the first projection operation, wherein constructing the first projection control block comprises constructing a projection control element corresponding to a variable-length column in the plurality of input rows, and wherein the projection control element specifies information about variable offsets and lengths of the variable-length column in the plurality of input rows;
• offloading the first projection operation to a hardware accelerator;
• and
• providing the first projection control block to the hardware accelerator, wherein the first projection control block enables the hardware accelerator to perform the first projection operation at streaming rate, and wherein the streaming rate is a rate sufficient for the hardware accelerator to process the plurality of input rows without stalling an incoming row stream.