I don't know about practical benchmarks yet, but GPUs have superior parallelism and superior memory bandwidth compared to CPUs.
Classical "join" patterns, like merge-join, hash-join, and other such algorithms, have been run on GPUs with outstanding efficiency. Taking advantage of the parallelism.
A GPU merge-join is a strange beast though. See here for details: https://moderngpu.github.io/join.html . So its a weird algorithm, but it is clearly far more efficient than anything a traditional CPU could ever hope to accomplish.
In any case, it is clear that the high-memory bandwidth of GPUs, coupled with its parallel processors, makes the GPU a superior choice over CPUs for the relational merge-join algorithm.
GPUs probably can't be used effectively in all database operations. But they can at LEAST be used efficiently in "equijoin table", one of the most fundamental and common operations of a modern database. (How many times have you seen "JOIN Table1.id == Table2.id"??) As such, I expect GPUs to eventually be a common accelerator for SQL Databases. The only problem now is building the software to make this possible.
At SQream (a GPU-accelerated data warehouse) we use the GPU for many operations, including sorting, aggregating, joining, transformations, projections, etc.
We augment the GPU algorithms with external CPU algorithms when the GPU implementations aren't ideal or can't run due to memory constraints.
Classical "join" patterns, like merge-join, hash-join, and other such algorithms, have been run on GPUs with outstanding efficiency. Taking advantage of the parallelism.
A GPU merge-join is a strange beast though. See here for details: https://moderngpu.github.io/join.html . So its a weird algorithm, but it is clearly far more efficient than anything a traditional CPU could ever hope to accomplish.
In any case, it is clear that the high-memory bandwidth of GPUs, coupled with its parallel processors, makes the GPU a superior choice over CPUs for the relational merge-join algorithm.
GPUs probably can't be used effectively in all database operations. But they can at LEAST be used efficiently in "equijoin table", one of the most fundamental and common operations of a modern database. (How many times have you seen "JOIN Table1.id == Table2.id"??) As such, I expect GPUs to eventually be a common accelerator for SQL Databases. The only problem now is building the software to make this possible.