stmtdiagnostics: remove unused JSON trace datum

In 2d05a54 we stopped writing JSON
trace datums to the system table, but some remnants of that work still
remained. This commit cleans that up.

Release note: None

pkg/sql/explain_bundle.go

@@ -88,26 +88,20 @@ func setExplainBundleResult(
 	return nil
 }
 
-// traceToJSON converts a trace to a JSON datum suitable for the
-// system.statement_diagnostics.trace column. In case of error, the returned
-// datum is DNull. Also returns the string representation of the trace.
+// traceToJSON returns the string representation of the trace in JSON format.
 //
 // traceToJSON assumes that the first span in the recording contains all the
 // other spans.
-func traceToJSON(trace tracing.Recording) (tree.Datum, string, error) {
+func traceToJSON(trace tracing.Recording) (string, error) {
 	root := normalizeSpan(trace[0], trace)
 	marshaller := jsonpb.Marshaler{
 		Indent: "\t",
 	}
 	str, err := marshaller.MarshalToString(&root)
 	if err != nil {
-		return tree.DNull, "", err
-	}
-	d, err := tree.ParseDJSON(str)
-	if err != nil {
-		return tree.DNull, "", err
+		return "", err
 	}
-	return d, str, nil
+	return str, nil
 }
 
 func normalizeSpan(s tracingpb.RecordedSpan, trace tracing.Recording) tracingpb.NormalizedSpan {
@@ -132,9 +126,6 @@ type diagnosticsBundle struct {
 	// Zip file binary data.
 	zip []byte
 
-	// Tracing data, as DJson (or DNull if it is not available).
-	traceJSON tree.Datum
-
 	// Stores any error in the collection, building, or insertion of the bundle.
 	collectionErr error
 
@@ -164,14 +155,14 @@ func buildStatementBundle(
 	b.addExecPlan(planString)
 	b.addDistSQLDiagrams()
 	b.addExplainVec()
-	traceJSON := b.addTrace()
+	b.addTrace()
 	b.addEnv(ctx)
 
 	buf, err := b.finalize()
 	if err != nil {
 		return diagnosticsBundle{collectionErr: err}
 	}
-	return diagnosticsBundle{traceJSON: traceJSON, zip: buf.Bytes()}
+	return diagnosticsBundle{zip: buf.Bytes()}
 }
 
 // insert the bundle in statement diagnostics. Sets bundle.diagID and (in error
@@ -192,7 +183,6 @@ func (bundle *diagnosticsBundle) insert(
 		diagRequestID,
 		fingerprint,
 		tree.AsString(ast),
-		bundle.traceJSON,
 		bundle.zip,
 		bundle.collectionErr,
 	)
@@ -328,10 +318,11 @@ func (b *stmtBundleBuilder) addExplainVec() {
 	}
 }
 
-// addTrace adds two files to the bundle: one is a json representation of the
-// trace, the other one is a human-readable representation.
-func (b *stmtBundleBuilder) addTrace() tree.Datum {
-	traceJSON, traceJSONStr, err := traceToJSON(b.trace)
+// addTrace adds three files to the bundle: two are a json representation of the
+// trace (the default and the jaeger formats), the third one is a human-readable
+// representation.
+func (b *stmtBundleBuilder) addTrace() {
+	traceJSONStr, err := traceToJSON(b.trace)
 	if err != nil {
 		b.z.AddFile("trace.json", err.Error())
 	} else {
@@ -358,8 +349,6 @@ func (b *stmtBundleBuilder) addTrace() tree.Datum {
 	} else {
 		b.z.AddFile("trace-jaeger.json", jaegerJSON)
 	}
-
-	return traceJSON
 }
 
 func (b *stmtBundleBuilder) addEnv(ctx context.Context) {

pkg/sql/stmtdiagnostics/statement_diagnostics.go

@@ -333,7 +333,6 @@ func (r *Registry) InsertStatementDiagnostics(
 	requestID RequestID,
 	stmtFingerprint string,
 	stmt string,
-	traceJSON tree.Datum,
 	bundle []byte,
 	collectionErr error,
 ) (CollectedInstanceID, error) {