Hash Group Aggregate

Hash Group Aggregate resides in L1/benchmarks/hash_group_aggregate directory.

SELECT
        max(l_extendedprice), min(l_extendedprice), count_non_zero(l_extendedprice) as revenue
FROM
        Lineitem
GROUP BY
        l_orderkey
;

Here, Lineitem is a table filled with random data, which contains 2 columns named l_orderkey and l_extendedprice.

Dataset

This project uses 32-bit data for numeric fields. To benchmark 64-bit performance, edit host/table_dt.h and make TPCH_INT an int64_t.

Executable Usage

• Work Directory(Step 1)

The steps for library download and environment setup can be found in Vitis Database Library. For getting the design,

cd L1/benchmarks/hash_group_aggregate

• Build kernel(Step 2)

Run the following make command to build your XCLBIN and host binary targeting a specific device. Please be noticed that this process will take a long time, maybe couple of hours.

make run TARGET=hw DEVICE=xilinx_u280_xdma_201920_3 HOST_ARCH=x86

• Run kernel(Step 3)

To get the benchmark results, please run the following command.

./build_dir.hw.xilinx_u280_xdma_201920_3/test_aggr.exe -xclbin build_dir.hw.xilinx_u280_xdma_201920_3/hash_aggr_kernel.xclbin

Hash Group Aggregate Input Arguments:

Usage: test_aggr.exe -xclbin
       -xclbin:      the kernel name

Note: Default arguments are set in Makefile, you can use other platforms to build and run.

• Example output(Step 4)

---------- Query with TPC-H 1G Data ----------

 select max(l_extendedprice), min(l_extendedprice),
        sum(l_extendedprice), count(l_extendedprice)
 from lineitem
 group by l_orderkey
 ---------------------------------------------
Host map Buffer has been allocated.
Lineitem 6000000 rows
Lineitem table has been read from disk
insert: idx=0 key=180 i_pld=30bca4
insert: idx=1 key=377 i_pld=6137c
...
Checking: idx=3e5 key:192 pld:d20c5351
Checking: idx=3e6 key:385 pld:c074aacf
Checking: idx=3e7 key:104 pld:e6713746
No error found!
kernel done!
kernel_result_num=0x3e8
FPGA execution time of 3 runs: 104107 usec
Average execution per run: 34702 usec
INFO: kernel 0: execution time 31273 usec
INFO: kernel 1: execution time 56554 usec
INFO: kernel 2: execution time 43182 usec
read_config: pu_end_status_a[0]=0x22222222
read_config: pu_end_status_b[0]=0x22222222
read_config: pu_end_status_a[1]=0x08
read_config: pu_end_status_b[1]=0x08
read_config: pu_end_status_a[2]=0x08
read_config: pu_end_status_b[2]=0x08
read_config: pu_end_status_a[3]=0x3e8
read_config: pu_end_status_b[3]=0x3e8
ref_result_num=3e8
---------------------------------------------
PASS!

---------------------------------------------

Profiling

The hash group aggregate design is validated on Alveo U280 board at 200 MHz frequency. The hardware resource utilizations are listed in the following table.

Table 1 Hardware resources for hash group aggregate

Name	LUT	BRAM	URAM	DSP
Platform	202971	427	0	10
hash_aggr_kernel	184064	207	256	0
User Budget	1099749	1589	960	9014
Percentage	16.74%	13.03%	26.67%	0

The performance is shown below:

In above test, table Lineitem has 2 columns and 6000000 rows. This means that the design takes 34.702ms to process 45.78MB data, so it achieves 1.29GB/s throughput.