Make it possible to disable schemas (#234)

source.go

@@ -113,6 +113,7 @@ func (s *Source) Open(ctx context.Context, pos opencdc.Position) error {
 			Tables:            s.config.Tables,
 			TableKeys:         s.tableKeys,
 			WithSnapshot:      s.config.SnapshotMode == source.SnapshotModeInitial,
+			WithAvroSchema:    s.config.WithAvroSchema,
 			SnapshotFetchSize: s.config.SnapshotFetchSize,
 		})
 		if err != nil {

source/logrepl/cdc.go

@@ -65,7 +65,7 @@ func NewCDCIterator(ctx context.Context, pool *pgxpool.Pool, c CDCConfig) (*CDCI
 	}
 
 	records := make(chan opencdc.Record)
-	handler := NewCDCHandler(internal.NewRelationSet(), c.TableKeys, records)
+	handler := NewCDCHandler(internal.NewRelationSet(), c.TableKeys, records, c.WithAvroSchema)
 
 	sub, err := internal.CreateSubscription(
 		ctx,

source/logrepl/cdc_test.go

@@ -475,6 +475,7 @@ func testCDCIterator(ctx context.Context, t *testing.T, pool *pgxpool.Pool, tabl
 		TableKeys:       map[string]string{table: "id"},
 		PublicationName: table, // table is random, reuse for publication name
 		SlotName:        table, // table is random, reuse for slot name
+		WithAvroSchema:  true,
 	}
 
 	i, err := NewCDCIterator(ctx, pool, config)

source/logrepl/combined.go

@@ -48,6 +48,7 @@ type Config struct {
 	Tables            []string
 	TableKeys         map[string]string
 	WithSnapshot      bool
+	WithAvroSchema    bool
 	SnapshotFetchSize int
 }
 
@@ -178,6 +179,7 @@ func (c *CombinedIterator) initCDCIterator(ctx context.Context, pos position.Pos
 		PublicationName: c.conf.PublicationName,
 		Tables:          c.conf.Tables,
 		TableKeys:       c.conf.TableKeys,
+		WithAvroSchema:  c.conf.WithAvroSchema,
 	})
 	if err != nil {
 		return fmt.Errorf("failed to create CDC iterator: %w", err)
@@ -199,11 +201,12 @@ func (c *CombinedIterator) initSnapshotIterator(ctx context.Context, pos positio
 	}
 
 	snapshotIterator, err := snapshot.NewIterator(ctx, c.pool, snapshot.Config{
-		Position:     c.conf.Position,
-		Tables:       c.conf.Tables,
-		TableKeys:    c.conf.TableKeys,
-		TXSnapshotID: c.cdcIterator.TXSnapshotID(),
-		FetchSize:    c.conf.SnapshotFetchSize,
+		Position:       c.conf.Position,
+		Tables:         c.conf.Tables,
+		TableKeys:      c.conf.TableKeys,
+		TXSnapshotID:   c.cdcIterator.TXSnapshotID(),
+		FetchSize:      c.conf.SnapshotFetchSize,
+		WithAvroSchema: c.conf.WithAvroSchema,
 	})
 	if err != nil {
 		return fmt.Errorf("failed to create snapshot iterator: %w", err)

source/logrepl/handler.go

@@ -36,15 +36,17 @@ type CDCHandler struct {
 	out         chan<- opencdc.Record
 	lastTXLSN   pglogrepl.LSN
 
+	withAvroSchema bool
 	keySchemas     map[string]cschema.Schema
 	payloadSchemas map[string]cschema.Schema
 }
 
-func NewCDCHandler(rs *internal.RelationSet, tableKeys map[string]string, out chan<- opencdc.Record) *CDCHandler {
+func NewCDCHandler(rs *internal.RelationSet, tableKeys map[string]string, out chan<- opencdc.Record, withAvroSchema bool) *CDCHandler {
 	return &CDCHandler{
 		tableKeys:      tableKeys,
 		relationSet:    rs,
 		out:            out,
+		withAvroSchema: withAvroSchema,
 		keySchemas:     make(map[string]cschema.Schema),
 		payloadSchemas: make(map[string]cschema.Schema),
 	}
@@ -245,6 +247,9 @@ func (*CDCHandler) buildPosition(lsn pglogrepl.LSN) opencdc.Position {
 // updateAvroSchema generates and stores avro schema based on the relation's row,
 // when usage of avro schema is requested.
 func (h *CDCHandler) updateAvroSchema(ctx context.Context, rel *pglogrepl.RelationMessage) error {
+	if !h.withAvroSchema {
+		return nil
+	}
 	// Payload schema
 	avroPayloadSch, err := schema.Avro.ExtractLogrepl(rel.RelationName+"_payload", rel)
 	if err != nil {
@@ -281,6 +286,9 @@ func (h *CDCHandler) updateAvroSchema(ctx context.Context, rel *pglogrepl.Relati
 }
 
 func (h *CDCHandler) attachSchemas(rec opencdc.Record, relationName string) {
+	if !h.withAvroSchema {
+		return
+	}
 	cschema.AttachPayloadSchemaToRecord(rec, h.payloadSchemas[relationName])
 	cschema.AttachKeySchemaToRecord(rec, h.keySchemas[relationName])
 }

source/snapshot/fetch_worker.go

@@ -44,11 +44,12 @@ var supportedKeyTypes = []string{
 }
 
 type FetchConfig struct {
-	Table        string
-	Key          string
-	TXSnapshotID string
-	FetchSize    int
-	Position     position.Position
+	Table          string
+	Key            string
+	TXSnapshotID   string
+	FetchSize      int
+	Position       position.Position
+	WithAvroSchema bool
 }
 
 var (
@@ -337,14 +338,17 @@ func (f *FetchWorker) buildFetchData(fields []pgconn.FieldDescription, values []
 		return FetchData{}, fmt.Errorf("failed to encode record data: %w", err)
 	}
 
-	return FetchData{
-		Key:           key,
-		Payload:       payload,
-		Position:      pos,
-		Table:         f.conf.Table,
-		PayloadSchema: *f.payloadSchema,
-		KeySchema:     *f.keySchema,
-	}, nil
+	fd := FetchData{
+		Key:      key,
+		Payload:  payload,
+		Position: pos,
+		Table:    f.conf.Table,
+	}
+	if f.conf.WithAvroSchema {
+		fd.PayloadSchema = *f.payloadSchema
+		fd.KeySchema = *f.keySchema
+	}
+	return fd, nil
 }
 
 func (f *FetchWorker) buildSnapshotPosition(fields []pgconn.FieldDescription, values []any) (position.SnapshotPosition, error) {
@@ -467,6 +471,10 @@ func (*FetchWorker) validateTable(ctx context.Context, table string, tx pgx.Tx)
 }
 
 func (f *FetchWorker) extractSchemas(ctx context.Context, fields []pgconn.FieldDescription) error {
+	if !f.conf.WithAvroSchema {
+		return nil
+	}
+
 	if f.payloadSchema == nil {
 		sdk.Logger(ctx).Debug().
 			Msgf("extracting payload schema for %v fields in %v", len(fields), f.conf.Table)

source/snapshot/iterator.go

@@ -31,11 +31,12 @@ import (
 var ErrIteratorDone = errors.New("snapshot complete")
 
 type Config struct {
-	Position     opencdc.Position
-	Tables       []string
-	TableKeys    map[string]string
-	TXSnapshotID string
-	FetchSize    int
+	Position       opencdc.Position
+	Tables         []string
+	TableKeys      map[string]string
+	TXSnapshotID   string
+	FetchSize      int
+	WithAvroSchema bool
 }
 
 type Iterator struct {
@@ -122,8 +123,10 @@ func (i *Iterator) buildRecord(d FetchData) opencdc.Record {
 	metadata["postgres.table"] = d.Table
 
 	rec := sdk.Util.Source.NewRecordSnapshot(pos, metadata, d.Key, d.Payload)
-	cschema.AttachKeySchemaToRecord(rec, d.KeySchema)
-	cschema.AttachPayloadSchemaToRecord(rec, d.PayloadSchema)
+	if i.conf.WithAvroSchema {
+		cschema.AttachKeySchemaToRecord(rec, d.KeySchema)
+		cschema.AttachPayloadSchemaToRecord(rec, d.PayloadSchema)
+	}
 
 	return rec
 }
@@ -135,11 +138,12 @@ func (i *Iterator) initFetchers(ctx context.Context) error {
 
 	for j, t := range i.conf.Tables {
 		w := NewFetchWorker(i.db, i.data, FetchConfig{
-			Table:        t,
-			Key:          i.conf.TableKeys[t],
-			TXSnapshotID: i.conf.TXSnapshotID,
-			Position:     i.lastPosition,
-			FetchSize:    i.conf.FetchSize,
+			Table:          t,
+			Key:            i.conf.TableKeys[t],
+			TXSnapshotID:   i.conf.TXSnapshotID,
+			Position:       i.lastPosition,
+			FetchSize:      i.conf.FetchSize,
+			WithAvroSchema: i.conf.WithAvroSchema,
 		})
 
 		if err := w.Validate(ctx); err != nil {