(seq dag.Seq)
| 80 | } |
| 81 | |
| 82 | func replaceJoinWithHashJoin(seq dag.Seq) { |
| 83 | walkT(reflect.ValueOf(seq), func(op dag.Op) dag.Op { |
| 84 | j, ok := op.(*dag.JoinOp) |
| 85 | if !ok { |
| 86 | return op |
| 87 | } |
| 88 | var lefts, rights []dag.Expr |
| 89 | for _, e := range splitPredicate(j.Cond) { |
| 90 | left, right, ok := equiJoinKeyExprs(e, j.LeftAlias, j.RightAlias) |
| 91 | if !ok { |
| 92 | return op |
| 93 | } |
| 94 | lefts = append(lefts, left) |
| 95 | rights = append(rights, right) |
| 96 | } |
| 97 | var left, right dag.Expr |
| 98 | if len(lefts) == 1 { |
| 99 | left, right = lefts[0], rights[0] |
| 100 | } else { |
| 101 | // XXX Perhaps we should merge record expressions? |
| 102 | left = buildTuple(lefts) |
| 103 | right = buildTuple(rights) |
| 104 | } |
| 105 | style := j.Style |
| 106 | if style == "cross" { |
| 107 | style = "inner" |
| 108 | } |
| 109 | return &dag.HashJoinOp{ |
| 110 | Kind: "HashJoinOp", |
| 111 | Style: style, |
| 112 | LeftAlias: j.LeftAlias, |
| 113 | RightAlias: j.RightAlias, |
| 114 | LeftKey: left, |
| 115 | RightKey: right, |
| 116 | } |
| 117 | }) |
| 118 | } |
| 119 | |
| 120 | func buildTuple(exprs []dag.Expr) dag.Expr { |
| 121 | var elems []dag.RecordElem |
no test coverage detected