diff --git a/internal/e2e/transaction_cases_test.go b/internal/e2e/transaction_cases_test.go
index 4e4e7e5b0..01d96ae51 100644
--- a/internal/e2e/transaction_cases_test.go
+++ b/internal/e2e/transaction_cases_test.go
@@ -58,6 +58,51 @@ func runTransactionCases(c transactClient, m *namespaceTestManager) func(*testin
 			assert.Len(t, resp.RelationTuples, 0)
 		})
 
+		t.Run("case=large inserts and deletes", func(t *testing.T) {
+			ns := []*namespace.Namespace{
+				{Name: t.Name() + "1"},
+				{Name: t.Name() + "2"},
+			}
+			m.add(t, ns...)
+
+			var tuples []*ketoapi.RelationTuple
+			for range 5001 {
+				tuples = append(tuples, &ketoapi.RelationTuple{
+					Namespace: ns[0].Name,
+					Object:    "o",
+					Relation:  "rel",
+					SubjectSet: &ketoapi.SubjectSet{
+						Namespace: ns[1].Name,
+						Object:    "o",
+						Relation:  "rel",
+					},
+				},
+					&ketoapi.RelationTuple{
+						Namespace: ns[0].Name,
+						Object:    "o",
+						Relation:  "rel",
+						SubjectID: pointerx.Ptr("sid"),
+					},
+				)
+			}
+
+			c.transactTuples(t, tuples, nil)
+
+			resp := c.queryTuple(t, &ketoapi.RelationQuery{
+				Namespace: &ns[0].Name,
+			})
+			for i := range tuples {
+				assert.Contains(t, resp.RelationTuples, tuples[i])
+			}
+
+			c.transactTuples(t, nil, tuples)
+
+			resp = c.queryTuple(t, &ketoapi.RelationQuery{
+				Namespace: &ns[0].Name,
+			})
+			assert.Len(t, resp.RelationTuples, 0)
+		})
+
 		t.Run("case=expand-api-display-access docs code sample", func(t *testing.T) {
 			files := &namespace.Namespace{Name: t.Name() + "files"}
 			directories := &namespace.Namespace{Name: t.Name() + "directories"}
diff --git a/internal/persistence/sql/query_test.go b/internal/persistence/sql/query_test.go
index 0fedea73f..c418def24 100644
--- a/internal/persistence/sql/query_test.go
+++ b/internal/persistence/sql/query_test.go
@@ -107,3 +107,23 @@ func TestBuildInsert(t *testing.T) {
 		now,
 	}, args)
 }
+
+func TestBuildInsertUUIDs(t *testing.T) {
+	t.Parallel()
+
+	nid := uuidx.NewV4()
+	foo, bar, baz := uuidx.NewV4(), uuidx.NewV4(), uuidx.NewV4()
+	uuids := []UUIDMapping{
+		{foo, "foo"},
+		{bar, "bar"},
+		{baz, "baz"},
+	}
+
+	q, args := buildInsertUUIDs(nid, uuids, "mysql")
+	assert.Equal(t, "INSERT IGNORE INTO keto_uuid_mappings (id, string_representation) VALUES (?,?),(?,?),(?,?)", q)
+	assert.Equal(t, []any{foo, "foo", bar, "bar", baz, "baz"}, args)
+
+	q, args = buildInsertUUIDs(nid, uuids, "anything else")
+	assert.Equal(t, "INSERT INTO keto_uuid_mappings (id, string_representation) VALUES (?,?),(?,?),(?,?) ON CONFLICT (id) DO NOTHING", q)
+	assert.Equal(t, []any{foo, "foo", bar, "bar", baz, "baz"}, args)
+}
diff --git a/internal/persistence/sql/relationtuples.go b/internal/persistence/sql/relationtuples.go
index efe0f4a25..a3e4b8e9b 100644
--- a/internal/persistence/sql/relationtuples.go
+++ b/internal/persistence/sql/relationtuples.go
@@ -177,7 +177,7 @@ func (p *Persister) DeleteRelationTuples(ctx context.Context, rs ...*relationtup
 	}
 
 	return p.Transaction(ctx, func(ctx context.Context) error {
-		for chunk := range slices.Chunk(rs, 500) {
+		for chunk := range slices.Chunk(rs, 250) {
 			q, args, err := buildDelete(p.NetworkID(ctx), chunk)
 			if err != nil {
 				return err
@@ -314,7 +314,7 @@ func (p *Persister) WriteRelationTuples(ctx context.Context, rs ...*relationtupl
 	commitTime := time.Now()
 
 	return p.Transaction(ctx, func(ctx context.Context) error {
-		for chunk := range slices.Chunk(rs, 500) {
+		for chunk := range slices.Chunk(rs, 250) {
 			q, args, err := buildInsert(commitTime, p.NetworkID(ctx), chunk)
 			if err != nil {
 				return err
diff --git a/internal/persistence/sql/uuid_mapping.go b/internal/persistence/sql/uuid_mapping.go
index 9b48b1259..22844716d 100644
--- a/internal/persistence/sql/uuid_mapping.go
+++ b/internal/persistence/sql/uuid_mapping.go
@@ -7,6 +7,7 @@ import (
 	"context"
 	"iter"
 	"maps"
+	"slices"
 	"strings"
 
 	"github.com/gofrs/uuid"
@@ -32,47 +33,6 @@ func (UUIDMapping) TableName() string {
 	return "keto_uuid_mappings"
 }
 
-func (p *Persister) batchToUUIDs(ctx context.Context, values []string, readOnly bool) (uuids []uuid.UUID, err error) {
-	if len(values) == 0 {
-		return
-	}
-
-	uuids = make([]uuid.UUID, len(values))
-	placeholderArray := make([]string, len(values))
-	args := make([]interface{}, 0, len(values)*2)
-	for i, val := range values {
-		uuids[i] = uuid.NewV5(p.NetworkID(ctx), val)
-		placeholderArray[i] = "(?, ?)"
-		args = append(args, uuids[i], val)
-	}
-	placeholders := strings.Join(placeholderArray, ", ")
-
-	p.d.Logger().WithField("values", values).WithField("UUIDs", uuids).Trace("adding UUID mappings")
-
-	if !readOnly {
-		// We need to write manual SQL here because the INSERT should not fail if
-		// the UUID already exists, but we still want to return an error if anything
-		// else goes wrong.
-		var query string
-		switch d := p.Connection(ctx).Dialect.Name(); d {
-		case "mysql":
-			query = `
-			INSERT IGNORE INTO keto_uuid_mappings (id, string_representation) VALUES ` + placeholders
-		default:
-			query = `
-			INSERT INTO keto_uuid_mappings (id, string_representation)
-			VALUES ` + placeholders + `
-			ON CONFLICT (id) DO NOTHING`
-		}
-
-		return uuids, sqlcon.HandleError(
-			p.Connection(ctx).RawQuery(query, args...).Exec(),
-		)
-	} else {
-		return uuids, nil
-	}
-}
-
 func (p *Persister) batchFromUUIDs(ctx context.Context, ids []uuid.UUID, opts ...x.PaginationOptionSetter) (res []string, err error) {
 	if len(ids) == 0 {
 		return
@@ -128,18 +88,52 @@ func (p *Persister) batchFromUUIDs(ctx context.Context, ids []uuid.UUID, opts ..
 	return
 }
 
-func (p *Persister) MapStringsToUUIDs(ctx context.Context, s ...string) (_ []uuid.UUID, err error) {
+func (p *Persister) MapStringsToUUIDs(ctx context.Context, values ...string) (uuids []uuid.UUID, err error) {
 	ctx, span := p.d.Tracer(ctx).Tracer().Start(ctx, "persistence.sql.MapStringsToUUIDs")
 	defer otelx.End(span, &err)
 
-	return p.batchToUUIDs(ctx, s, false)
+	if len(values) == 0 {
+		return
+	}
+
+	uuids, err = p.MapStringsToUUIDsReadOnly(ctx, values...)
+	if err != nil {
+		return nil, err
+	}
+
+	p.d.Logger().WithField("values", values).WithField("UUIDs", uuids).Trace("adding UUID mappings")
+
+	mappings := make([]UUIDMapping, len(values))
+	for i := range len(values) {
+		mappings[i] = UUIDMapping{
+			ID:                   uuids[i],
+			StringRepresentation: values[i],
+		}
+	}
+
+	err = p.Transaction(ctx, func(ctx context.Context) error {
+		for chunk := range slices.Chunk(mappings, 1000) {
+			query, args := buildInsertUUIDs(p.NetworkID(ctx), chunk, p.conn.Dialect.Name())
+			if err := p.Connection(ctx).RawQuery(query, args...).Exec(); err != nil {
+				return sqlcon.HandleError(err)
+			}
+		}
+		return nil
+	})
+
+	return uuids, err
 }
 
-func (p *Persister) MapStringsToUUIDsReadOnly(ctx context.Context, s ...string) (_ []uuid.UUID, err error) {
-	ctx, span := p.d.Tracer(ctx).Tracer().Start(ctx, "persistence.sql.MapStringsToUUIDsReadOnly")
-	defer otelx.End(span, &err)
+func (p *Persister) MapStringsToUUIDsReadOnly(ctx context.Context, ss ...string) (uuids []uuid.UUID, err error) {
+	// This function doesn't talk to the database or do anything interesting, so we don't need to trace it.
+	// ctx, span := p.d.Tracer(ctx).Tracer().Start(ctx, "persistence.sql.MapStringsToUUIDsReadOnly")
+	// defer otelx.End(span, &err)
 
-	return p.batchToUUIDs(ctx, s, true)
+	uuids = make([]uuid.UUID, len(ss))
+	for i := range ss {
+		uuids[i] = uuid.NewV5(p.NetworkID(ctx), ss[i])
+	}
+	return uuids, nil
 }
 
 func (p *Persister) MapUUIDsToStrings(ctx context.Context, u ...uuid.UUID) (_ []string, err error) {
@@ -148,3 +142,39 @@ func (p *Persister) MapUUIDsToStrings(ctx context.Context, u ...uuid.UUID) (_ []
 
 	return p.batchFromUUIDs(ctx, u)
 }
+
+func buildInsertUUIDs(nid uuid.UUID, values []UUIDMapping, dialect string) (query string, args []any) {
+	if len(values) == 0 {
+		return "", nil
+	}
+
+	const placeholder = "(?,?)"
+	const separator = ","
+
+	var q strings.Builder
+	args = make([]any, 0, len(values)*2)
+
+	if dialect == "mysql" {
+		q.WriteString("INSERT IGNORE INTO keto_uuid_mappings (id, string_representation) VALUES ")
+	} else {
+		q.WriteString("INSERT INTO keto_uuid_mappings (id, string_representation) VALUES ")
+	}
+
+	q.Grow(len(values)*(len(placeholder)+len(separator)) + 100)
+
+	for i, val := range values {
+		if i > 0 {
+			q.WriteString(separator)
+		}
+		q.WriteString(placeholder)
+		args = append(args, val.ID, val.StringRepresentation)
+	}
+
+	if dialect == "mysql" {
+		// nothing
+	} else {
+		q.WriteString(" ON CONFLICT (id) DO NOTHING")
+	}
+
+	return q.String(), args
+}