1. A method for resolving a plurality of in-memory issues associated with parallel query execution of a database operation on a database utilizing a graphics processing unit (GPU) having a plurality of GPU multiprocessors, the method comprising: tying a table choice to a number of accesses per second made to a table such that selection of the table choice corresponds with the number of accesses per second made to the table, wherein the table choice is a first of the plurality of in-memory issues; and synchronizing threads in a same shared GPU multiprocessor using a first thread synchronization call through a local memory to avoid thread blocks and to maintain concurrency in the same shared GPU multiprocessor, wherein each of the plurality of GPU multiprocessors includes the local memory shared by threads running on the same shared GPU multiprocessor; and synchronizing threads in a different shared GPU multiprocessor using a second thread synchronization call through a global memory to maintain concurrency, wherein concurrency is a second of the plurality of in-memory issues, wherein the global memory is shared between the plurality of GPU multiprocessors, and wherein the parallel query execution of the database operation is performed solely by the GPU.