some buffer?

Author: James Cor

sql/rowexec/agg.go

@@ -238,8 +238,9 @@ func (i *groupByGroupingIter) Dispose() {
 }
 
 func groupingKey(ctx *sql.Context, exprs []sql.Expression, row sql.Row) (uint64, error) {
-	var keyRow = make(sql.Row, len(exprs))
 	var keySch = make(sql.Schema, len(exprs))
+	keyRow := sql.GetRow(len(exprs))
+	defer sql.PutRow(keyRow)
 	for i, expr := range exprs {
 		v, err := expr.Eval(ctx, row)
 		if err != nil {

sql/rowexec/builder.go

@@ -15,11 +15,9 @@
 package rowexec
 
 import (
-	"runtime/trace"
-	"sync"
-
 	"github.com/dolthub/go-mysql-server/sql"
 	"github.com/dolthub/go-mysql-server/sql/plan"
+	"runtime/trace"
 )
 
 var DefaultBuilder = &BaseBuilder{}
@@ -59,19 +57,3 @@ func FinalizeIters(ctx *sql.Context, analyzed sql.Node, qFlags *sql.QueryFlags,
 	iter = AddExpressionCloser(analyzed, iter)
 	return iter, sch, nil
 }
-
-// TODO: find a proper place for this
-var rowBuffers = sync.Pool{
-	New: func() interface{} {
-		return make(sql.Row, 0, 4096) // TODO: this is apparently max number of columns
-	},
-}
-
-func GetRow(length int) sql.Row {
-	row := rowBuffers.Get().(sql.Row)
-	return row[:length]
-}
-
-func PutRow(row sql.Row) {
-	rowBuffers.Put(row[:0])
-}

sql/rowexec/merge_join.go

@@ -46,8 +46,8 @@ func newMergeJoinIter(ctx *sql.Context, b sql.NodeExecBuilder, j *plan.JoinNode,
 		return nil, err
 	}
 
-	fullRow := GetRow(len(row) + len(j.Left().Schema()) + len(j.Right().Schema()))
-	// TODO: what is this for
+	fullRow := sql.GetRow(len(row) + len(j.Left().Schema()) + len(j.Right().Schema()))
+	// TODO: what is this for?
 	fullRow[0] = row
 	if len(row) > 0 {
 		copy(fullRow[0:], row[:])
@@ -264,7 +264,7 @@ func (i *mergeJoinIter) Next(ctx *sql.Context) (sql.Row, error) {
 			}
 			nextState = msExhaustCheck
 		case msSelect:
-			ret = i.copyReturnRow()
+			ret = i.copyReturnRow() // TODO: only copy once we know we're going to return this
 			currLeftMatched := i.leftMatched
 
 			ok, err := i.sel(ctx, ret)
@@ -587,6 +587,6 @@ func (i *mergeJoinIter) Close(ctx *sql.Context) (err error) {
 		}
 	}
 
-	PutRow(i.fullRow)
+	sql.PutRow(i.fullRow)
 	return err
 }

sql/rows.go

@@ -20,6 +20,7 @@ import (
 	"github.com/dolthub/vitess/go/vt/proto/query"
 	"io"
 	"strings"
+	"sync"
 )
 
 // Row is a tuple of values.
@@ -67,6 +68,22 @@ func (r Row) Equals(ctx *Context, row Row, schema Schema) (bool, error) {
 	return true, nil
 }
 
+// TODO: find a proper place for this
+var rowBuffers = sync.Pool{
+	New: func() interface{} {
+		return make(Row, 0, 4096) // max number of columns for a table
+	},
+}
+
+func GetRow(length int) Row {
+	row := rowBuffers.Get().(Row)
+	return row[:length]
+}
+
+func PutRow(row Row) {
+	rowBuffers.Put(row[:0])
+}
+
 // FormatRow returns a formatted string representing this row's values
 func FormatRow(row Row) string {
 	var sb strings.Builder