From 9e4dbea26567a388e7672b5d98ee53f2054e4d56 Mon Sep 17 00:00:00 2001
From: James Cor <james@dolthub.com>
Date: Wed, 6 Aug 2025 16:39:11 -0700
Subject: [PATCH 1/6] replace append with cast

---
 sql/types/decimal.go       | 3 ++-
 sql/types/json.go          | 3 ++-
 sql/types/system_enum.go   | 3 ++-
 sql/types/system_set.go    | 3 ++-
 sql/types/system_string.go | 3 ++-
 5 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/sql/types/decimal.go b/sql/types/decimal.go
index ed69509184..45cd0043cb 100644
--- a/sql/types/decimal.go
+++ b/sql/types/decimal.go
@@ -303,7 +303,8 @@ func (t DecimalType_) SQL(ctx *sql.Context, dest []byte, v interface{}) (sqltype
 	if err != nil {
 		return sqltypes.Value{}, err
 	}
-	val := AppendAndSliceString(dest, t.DecimalValueStringFixed(value.Decimal))
+	//val := AppendAndSliceString(dest, t.DecimalValueStringFixed(value.Decimal))
+	val := []byte(t.DecimalValueStringFixed(value.Decimal))
 	return sqltypes.MakeTrusted(sqltypes.Decimal, val), nil
 }
 
diff --git a/sql/types/json.go b/sql/types/json.go
index 44cb3434f9..4ced0ed009 100644
--- a/sql/types/json.go
+++ b/sql/types/json.go
@@ -154,7 +154,8 @@ func (t JsonType) SQL(ctx *sql.Context, dest []byte, v interface{}) (sqltypes.Va
 		if err != nil {
 			return sqltypes.NULL, err
 		}
-		val = AppendAndSliceString(dest, str)
+		//val = AppendAndSliceString(dest, str)
+		val = []byte(str)
 	}
 
 	return sqltypes.MakeTrusted(sqltypes.TypeJSON, val), nil
diff --git a/sql/types/system_enum.go b/sql/types/system_enum.go
index c6b85b57f9..02d7993990 100644
--- a/sql/types/system_enum.go
+++ b/sql/types/system_enum.go
@@ -157,7 +157,8 @@ func (t systemEnumType) SQL(ctx *sql.Context, dest []byte, v interface{}) (sqlty
 		return sqltypes.Value{}, err
 	}
 
-	val := AppendAndSliceString(dest, v.(string))
+	//val := AppendAndSliceString(dest, v.(string))
+	val := []byte(v.(string))
 
 	return sqltypes.MakeTrusted(t.Type(), val), nil
 }
diff --git a/sql/types/system_set.go b/sql/types/system_set.go
index fd1e0fabee..8a42675047 100644
--- a/sql/types/system_set.go
+++ b/sql/types/system_set.go
@@ -143,7 +143,8 @@ func (t systemSetType) SQL(ctx *sql.Context, dest []byte, v interface{}) (sqltyp
 		return sqltypes.Value{}, err
 	}
 
-	val := AppendAndSliceString(dest, value)
+	//val := AppendAndSliceString(dest, value)
+	val := []byte(value)
 
 	return sqltypes.MakeTrusted(t.Type(), val), nil
 }
diff --git a/sql/types/system_string.go b/sql/types/system_string.go
index 07459cb26e..f848690c75 100644
--- a/sql/types/system_string.go
+++ b/sql/types/system_string.go
@@ -102,7 +102,8 @@ func (t systemStringType) SQL(ctx *sql.Context, dest []byte, v interface{}) (sql
 		return sqltypes.Value{}, err
 	}
 
-	val := AppendAndSliceString(dest, v.(string))
+	//val := AppendAndSliceString(dest, v.(string))
+	val := []byte(v.(string))
 
 	return sqltypes.MakeTrusted(t.Type(), val), nil
 }

From cfc8eb37d52f797064f19b3a5ad072836a90dc08 Mon Sep 17 00:00:00 2001
From: James Cor <james@dolthub.com>
Date: Thu, 7 Aug 2025 10:22:23 -0700
Subject: [PATCH 2/6] revert and try make

---
 sql/types/decimal.go       |  3 +--
 sql/types/json.go          |  3 +--
 sql/types/strings.go       | 14 +++++---------
 sql/types/system_enum.go   |  3 +--
 sql/types/system_set.go    |  3 +--
 sql/types/system_string.go |  3 +--
 6 files changed, 10 insertions(+), 19 deletions(-)

diff --git a/sql/types/decimal.go b/sql/types/decimal.go
index 45cd0043cb..ed69509184 100644
--- a/sql/types/decimal.go
+++ b/sql/types/decimal.go
@@ -303,8 +303,7 @@ func (t DecimalType_) SQL(ctx *sql.Context, dest []byte, v interface{}) (sqltype
 	if err != nil {
 		return sqltypes.Value{}, err
 	}
-	//val := AppendAndSliceString(dest, t.DecimalValueStringFixed(value.Decimal))
-	val := []byte(t.DecimalValueStringFixed(value.Decimal))
+	val := AppendAndSliceString(dest, t.DecimalValueStringFixed(value.Decimal))
 	return sqltypes.MakeTrusted(sqltypes.Decimal, val), nil
 }
 
diff --git a/sql/types/json.go b/sql/types/json.go
index 4ced0ed009..44cb3434f9 100644
--- a/sql/types/json.go
+++ b/sql/types/json.go
@@ -154,8 +154,7 @@ func (t JsonType) SQL(ctx *sql.Context, dest []byte, v interface{}) (sqltypes.Va
 		if err != nil {
 			return sqltypes.NULL, err
 		}
-		//val = AppendAndSliceString(dest, str)
-		val = []byte(str)
+		val = AppendAndSliceString(dest, str)
 	}
 
 	return sqltypes.MakeTrusted(sqltypes.TypeJSON, val), nil
diff --git a/sql/types/strings.go b/sql/types/strings.go
index 96fadd5498..e817f569f8 100644
--- a/sql/types/strings.go
+++ b/sql/types/strings.go
@@ -480,7 +480,7 @@ func ConvertToBytes(ctx context.Context, v interface{}, t sql.StringType, dest [
 				val = append(dest, b...)
 				start = len(dest)
 			}
-			val = append(val, bytes.Repeat([]byte{0}, int(st.maxCharLength)-len(val))...)
+			val = append(val, make([]byte, int(st.maxCharLength)-len(val))...)
 		}
 	}
 	val = val[start:]
@@ -715,10 +715,13 @@ func (t StringType) SQL(ctx *sql.Context, dest []byte, v interface{}) (sqltypes.
 		var valueBytes []byte
 		switch v := v.(type) {
 		case JSONBytes:
-			valueBytes, err = v.GetBytes(ctx)
+			// TODO: put on dest?
+			val, err = v.GetBytes(ctx)
 			if err != nil {
 				return sqltypes.Value{}, err
 			}
+			dest = append(dest, val...)
+			valueBytes = dest[start:]
 		case []byte:
 			valueBytes = v
 		case string:
@@ -893,10 +896,3 @@ func AppendAndSliceString(buffer []byte, addition string) (slice []byte) {
 	slice = buffer[stop:]
 	return
 }
-
-func AppendAndSliceBytes(buffer, addition []byte) (slice []byte) {
-	stop := len(buffer)
-	buffer = append(buffer, addition...)
-	slice = buffer[stop:]
-	return
-}
diff --git a/sql/types/system_enum.go b/sql/types/system_enum.go
index 02d7993990..c6b85b57f9 100644
--- a/sql/types/system_enum.go
+++ b/sql/types/system_enum.go
@@ -157,8 +157,7 @@ func (t systemEnumType) SQL(ctx *sql.Context, dest []byte, v interface{}) (sqlty
 		return sqltypes.Value{}, err
 	}
 
-	//val := AppendAndSliceString(dest, v.(string))
-	val := []byte(v.(string))
+	val := AppendAndSliceString(dest, v.(string))
 
 	return sqltypes.MakeTrusted(t.Type(), val), nil
 }
diff --git a/sql/types/system_set.go b/sql/types/system_set.go
index 8a42675047..fd1e0fabee 100644
--- a/sql/types/system_set.go
+++ b/sql/types/system_set.go
@@ -143,8 +143,7 @@ func (t systemSetType) SQL(ctx *sql.Context, dest []byte, v interface{}) (sqltyp
 		return sqltypes.Value{}, err
 	}
 
-	//val := AppendAndSliceString(dest, value)
-	val := []byte(value)
+	val := AppendAndSliceString(dest, value)
 
 	return sqltypes.MakeTrusted(t.Type(), val), nil
 }
diff --git a/sql/types/system_string.go b/sql/types/system_string.go
index f848690c75..07459cb26e 100644
--- a/sql/types/system_string.go
+++ b/sql/types/system_string.go
@@ -102,8 +102,7 @@ func (t systemStringType) SQL(ctx *sql.Context, dest []byte, v interface{}) (sql
 		return sqltypes.Value{}, err
 	}
 
-	//val := AppendAndSliceString(dest, v.(string))
-	val := []byte(v.(string))
+	val := AppendAndSliceString(dest, v.(string))
 
 	return sqltypes.MakeTrusted(t.Type(), val), nil
 }

From b7ae058b985ec46dbad6157eee7e14bc68a18710 Mon Sep 17 00:00:00 2001
From: James Cor <james@dolthub.com>
Date: Thu, 7 Aug 2025 10:25:59 -0700
Subject: [PATCH 3/6] missed one

---
 sql/types/strings.go | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/sql/types/strings.go b/sql/types/strings.go
index e817f569f8..17eeaef901 100644
--- a/sql/types/strings.go
+++ b/sql/types/strings.go
@@ -15,7 +15,6 @@
 package types
 
 import (
-	"bytes"
 	"context"
 	"fmt"
 	"reflect"
@@ -715,13 +714,10 @@ func (t StringType) SQL(ctx *sql.Context, dest []byte, v interface{}) (sqltypes.
 		var valueBytes []byte
 		switch v := v.(type) {
 		case JSONBytes:
-			// TODO: put on dest?
-			val, err = v.GetBytes(ctx)
+			valueBytes, err = v.GetBytes(ctx)
 			if err != nil {
 				return sqltypes.Value{}, err
 			}
-			dest = append(dest, val...)
-			valueBytes = dest[start:]
 		case []byte:
 			valueBytes = v
 		case string:
@@ -760,7 +756,7 @@ func (t StringType) SQL(ctx *sql.Context, dest []byte, v interface{}) (sqltypes.
 			valueBytes, err = ConvertToBytes(ctx, v, t, dest)
 		}
 		if t.baseType == sqltypes.Binary {
-			val = append(val, bytes.Repeat([]byte{0}, int(t.maxCharLength)-len(val))...)
+			val = append(val, make([]byte, int(t.maxCharLength)-len(val))...)
 		}
 		// Note: MySQL does not validate charset when returning query results.
 		// It returns whatever data is stored, allowing users to query and clean up
@@ -780,7 +776,6 @@ func (t StringType) SQL(ctx *sql.Context, dest []byte, v interface{}) (sqltypes.
 			snippetStr := strings2.ToValidUTF8(string(snippet), string(utf8.RuneError))
 			return sqltypes.Value{}, sql.ErrCharSetFailedToEncode.New(resultCharset.Name(), utf8.ValidString(snippetStr), snippet)
 		}
-		//val = AppendAndSliceBytes(dest, encodedBytes)
 		val = encodedBytes
 	}
 

From 5e517250039ddf5d7cafefe9e6319714944761fa Mon Sep 17 00:00:00 2001
From: James Cor <james@dolthub.com>
Date: Thu, 7 Aug 2025 13:23:36 -0700
Subject: [PATCH 4/6] reduce row allocations

---
 sql/rowexec/agg.go       | 18 ++++++++++--------
 sql/rowexec/ddl_iters.go |  2 +-
 sql/rowexec/rel.go       |  8 +++-----
 sql/types/number.go      |  2 +-
 4 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/sql/rowexec/agg.go b/sql/rowexec/agg.go
index 384e8efe91..a80b30f5e9 100644
--- a/sql/rowexec/agg.go
+++ b/sql/rowexec/agg.go
@@ -117,6 +117,8 @@ type groupByGroupingIter struct {
 	pos           int
 	child         sql.RowIter
 	dispose       sql.DisposeFunc
+	keyRow        sql.Row
+	keySch        sql.Schema
 }
 
 func newGroupByGroupingIter(
@@ -128,6 +130,8 @@ func newGroupByGroupingIter(
 		selectedExprs: selectedExprs,
 		groupByExprs:  groupByExprs,
 		child:         child,
+		keyRow:        make(sql.Row, len(groupByExprs)),
+		keySch:        make(sql.Schema, len(groupByExprs)),
 	}
 }
 
@@ -167,7 +171,7 @@ func (i *groupByGroupingIter) compute(ctx *sql.Context) error {
 			return err
 		}
 
-		key, err := groupingKey(ctx, i.groupByExprs, row)
+		key, err := i.groupingKey(ctx, i.groupByExprs, row)
 		if err != nil {
 			return err
 		}
@@ -237,10 +241,8 @@ 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))
-	for i, expr := range exprs {
+func (i *groupByGroupingIter) groupingKey(ctx *sql.Context, exprs []sql.Expression, row sql.Row) (uint64, error) {
+	for idx, expr := range exprs {
 		v, err := expr.Eval(ctx, row)
 		if err != nil {
 			return 0, err
@@ -256,10 +258,10 @@ func groupingKey(ctx *sql.Context, exprs []sql.Expression, row sql.Row) (uint64,
 			v = string(val)
 		}
 
-		keyRow[i] = v
-		keySch[i] = &sql.Column{Type: typ}
+		i.keyRow[idx] = v
+		i.keySch[idx] = &sql.Column{Type: typ}
 	}
-	return hash.HashOf(ctx, keySch, keyRow)
+	return hash.HashOf(ctx, i.keySch, i.keyRow)
 }
 
 func newAggregationBuffer(expr sql.Expression) (sql.AggregationBuffer, error) {
diff --git a/sql/rowexec/ddl_iters.go b/sql/rowexec/ddl_iters.go
index bf8a0b5797..1dc4f9460d 100644
--- a/sql/rowexec/ddl_iters.go
+++ b/sql/rowexec/ddl_iters.go
@@ -109,7 +109,7 @@ func (l *loadDataIter) Next(ctx *sql.Context) (returnRow sql.Row, returnErr erro
 		}
 	}
 
-	return sql.NewRow(row...), nil
+	return row, nil
 }
 
 func (l *loadDataIter) Close(ctx *sql.Context) error {
diff --git a/sql/rowexec/rel.go b/sql/rowexec/rel.go
index 391a9a61e1..8cc491428f 100644
--- a/sql/rowexec/rel.go
+++ b/sql/rowexec/rel.go
@@ -55,7 +55,7 @@ func (b *BaseBuilder) buildTopN(ctx *sql.Context, n *plan.TopN, row sql.Row) (sq
 func (b *BaseBuilder) buildValueDerivedTable(ctx *sql.Context, n *plan.ValueDerivedTable, row sql.Row) (sql.RowIter, error) {
 	rows := make([]sql.Row, len(n.ExpressionTuples))
 	for i, et := range n.ExpressionTuples {
-		vals := make([]interface{}, len(et))
+		rows[i] = make(sql.Row, len(et))
 		for j, e := range et {
 			var err error
 			p, err := e.Eval(ctx, row)
@@ -63,17 +63,15 @@ func (b *BaseBuilder) buildValueDerivedTable(ctx *sql.Context, n *plan.ValueDeri
 				return nil, err
 			}
 			// cast all row values to the most permissive type
-			vals[j], _, err = n.Schema()[j].Type.Convert(ctx, p)
+			rows[i][j], _, err = n.Schema()[j].Type.Convert(ctx, p)
 			if err != nil {
 				return nil, err
 			}
 			// decimalType.Convert() does not use the given type precision and scale information
 			if t, ok := n.Schema()[j].Type.(sql.DecimalType); ok {
-				vals[j] = vals[j].(decimal.Decimal).Round(int32(t.Scale()))
+				rows[i][j] = rows[i][j].(decimal.Decimal).Round(int32(t.Scale()))
 			}
 		}
-
-		rows[i] = sql.NewRow(vals...)
 	}
 
 	return sql.RowsToRowIter(rows...), nil
diff --git a/sql/types/number.go b/sql/types/number.go
index af0d6a498f..20bbd1d961 100644
--- a/sql/types/number.go
+++ b/sql/types/number.go
@@ -601,7 +601,7 @@ func (t NumberTypeImpl_) SQL(ctx *sql.Context, dest []byte, v interface{}) (sqlt
 		case []byte:
 			dest = str
 		case string:
-			dest = []byte(str)
+			dest = append(dest, str...)
 		default:
 			return sqltypes.Value{}, err
 		}

From 9d5ded5af4f5505ab5975c320321d36c1eebe940 Mon Sep 17 00:00:00 2001
From: James Cor <james@dolthub.com>
Date: Fri, 8 Aug 2025 11:04:05 -0700
Subject: [PATCH 5/6] clean up

---
 sql/rowexec/rel.go  | 7 ++++---
 sql/types/number.go | 2 +-
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/sql/rowexec/rel.go b/sql/rowexec/rel.go
index 8cc491428f..42942213f9 100644
--- a/sql/rowexec/rel.go
+++ b/sql/rowexec/rel.go
@@ -55,7 +55,7 @@ func (b *BaseBuilder) buildTopN(ctx *sql.Context, n *plan.TopN, row sql.Row) (sq
 func (b *BaseBuilder) buildValueDerivedTable(ctx *sql.Context, n *plan.ValueDerivedTable, row sql.Row) (sql.RowIter, error) {
 	rows := make([]sql.Row, len(n.ExpressionTuples))
 	for i, et := range n.ExpressionTuples {
-		rows[i] = make(sql.Row, len(et))
+		vals := make(sql.Row, len(et))
 		for j, e := range et {
 			var err error
 			p, err := e.Eval(ctx, row)
@@ -63,15 +63,16 @@ func (b *BaseBuilder) buildValueDerivedTable(ctx *sql.Context, n *plan.ValueDeri
 				return nil, err
 			}
 			// cast all row values to the most permissive type
-			rows[i][j], _, err = n.Schema()[j].Type.Convert(ctx, p)
+			vals[j], _, err = n.Schema()[j].Type.Convert(ctx, p)
 			if err != nil {
 				return nil, err
 			}
 			// decimalType.Convert() does not use the given type precision and scale information
 			if t, ok := n.Schema()[j].Type.(sql.DecimalType); ok {
-				rows[i][j] = rows[i][j].(decimal.Decimal).Round(int32(t.Scale()))
+				vals[j] = vals[j].(decimal.Decimal).Round(int32(t.Scale()))
 			}
 		}
+		rows[i] = vals
 	}
 
 	return sql.RowsToRowIter(rows...), nil
diff --git a/sql/types/number.go b/sql/types/number.go
index 20bbd1d961..9681949abd 100644
--- a/sql/types/number.go
+++ b/sql/types/number.go
@@ -931,7 +931,7 @@ func (t NumberTypeImpl_) IsSigned() bool {
 	return false
 }
 
-// DisplayWidth() implements NumberType inteface.
+// DisplayWidth implements NumberType interface.
 func (t NumberTypeImpl_) DisplayWidth() int {
 	return t.displayWidth
 }

From 6c83e6d50f70409e7a84f3b2a05b3ab8a5a72837 Mon Sep 17 00:00:00 2001
From: James Cor <james@dolthub.com>
Date: Sun, 10 Aug 2025 22:53:25 -0700
Subject: [PATCH 6/6] comment

---
 sql/rowexec/agg.go | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/sql/rowexec/agg.go b/sql/rowexec/agg.go
index a80b30f5e9..a24cecb7a6 100644
--- a/sql/rowexec/agg.go
+++ b/sql/rowexec/agg.go
@@ -117,8 +117,10 @@ type groupByGroupingIter struct {
 	pos           int
 	child         sql.RowIter
 	dispose       sql.DisposeFunc
-	keyRow        sql.Row
-	keySch        sql.Schema
+
+	// buffers to reduce slice allocations
+	keyRow sql.Row
+	keySch sql.Schema
 }
 
 func newGroupByGroupingIter(