class xf::database::gqe::Joiner

#include "gqe_join.hpp"

Overview

class Joiner: public xf::database::gqe::Base

Inherited Members

Methods

Joiner

Joiner (FpgaInit& obj)

constructor of Joiner .

Passing FpgaInit obj to Joiner class. Splitting FpgaInit (OpenCL context, program, commandqueue, host/device buffers creation/allocation etc.) and Joiner Init, guaranteens OpenCL stuff are not released after each join call. So the joiner may launch multi-times.

Parameters:

obj the FpgaInit instance.

run

ErrCode run (
    Table& tab_a,
    std::string filter_a,
    Table& tab_b,
    std::string filter_b,
    std::string join_str,
    Table& tab_c,
    std::string output_str,
    int join_type = INNER_JOIN,
    JoinStrategyBase* strategyimp = nullptr
    )

Run join with the input arguments defined strategy, which includes.

  • solution: the join solution (direct-join or partation-join)
  • sec_o: left table sec number
  • sec_l: right table sec number
  • slice_num: the slice number that used in probe
  • log_part, the partition number of left/right table
  • coef_exp_partO: the expansion coefficient of table O result buffer size / input buffer size, this param affects the output buffer size, but not the perf
  • coef_exp_partL: the expansion coefficient of table L result buffer size / input buffer size, this param affects the output buffer size, but not the perf
  • coef_exp_join: the expansion coefficient of result buffer size / input buffer size, this param affects the output buffer size, but not the perf

Usage:

  auto smanual = new gqe::JoinStrategyManualSet(solution, sec_o, sec_l, slice_num, log_part, coef_exp_partO,
coef_exp_partL, coef_exp_join);

  ErrCode err = bigjoin.run(
      tab_o, "o_rowid > 0",
      tab_l, "",
      "o_orderkey = l_orderkey",
      tab_c, "c1=l_orderkey, c2=o_rowid, c3=l_rowid",
      gqe::INNER_JOIN,
      smanual);
  delete smanual;

Table tab_o filter condition like “o_rowid > 0”, o_rowid is the col name of tab_o when no filter conditions, given empty fitler condition “”

The join condition like “left_join_key_0=right_join_key_0” when dual key join is enabled, using comma as the seperator in join condition, e.g. “left_join_key_0=right_join_key_0,left_join_key_1=right_join_key_1”

Output strings are like “output_c0 = tab_a_col/tab_b_col”, when several columns are output, using comma as the seperator

Parameters:

tab_a left table
filter_a filter condition of left table
tab_b right table
filter_b filter condition of right table
join_str join condition(s)
tab_c result table
output_str output columns
join_type INNER_JOIN(default) | SEMI_JOIN | ANTI_JOIN.
strategyimp pointer to an object of JoinStrategyBase or its derived type.