sql: stop writing trace to statement_diagnostics

The trace JSON stored in the statement_diagnostics table can be
arbitrarily large which causes problems for very large queries. This
trace is not currently used, and is contained in the bundle itself.
We stop writing it to the table in this commit. We can remove the
column altogether in a separate change (it will require a migration).

Fixes #61874.

Release note (bug fix): Fixed "command is too large" errors in some
cases when using EXPLAIN ANALYZE (DEBUG) or statement diagnostics on
complex queries.

docs/generated/http/full.md

@@ -2710,7 +2710,6 @@ Support status: [reserved](#support-status)
 | id | [int64](#cockroach.server.serverpb.StatementDiagnosticsResponse-int64) |  |  | [reserved](#support-status) |
 | statement_fingerprint | [string](#cockroach.server.serverpb.StatementDiagnosticsResponse-string) |  |  | [reserved](#support-status) |
 | collected_at | [google.protobuf.Timestamp](#cockroach.server.serverpb.StatementDiagnosticsResponse-google.protobuf.Timestamp) |  |  | [reserved](#support-status) |
-| trace | [string](#cockroach.server.serverpb.StatementDiagnosticsResponse-string) |  |  | [reserved](#support-status) |
 
 
 

pkg/server/serverpb/status.proto

@@ -974,7 +974,7 @@ message StatementDiagnostics {
   string statement_fingerprint = 2;
   google.protobuf.Timestamp collected_at = 3
     [ (gogoproto.nullable) = false, (gogoproto.stdtime) = true ];
-  string trace = 4;
+  reserved 4;
 }
 
 message StatementDiagnosticsRequest {

pkg/server/statement_diagnostics_requests.go

@@ -11,9 +11,7 @@
 package server
 
 import (
-	"bytes"
 	"context"
-	"encoding/json"
 	"time"
 
 	"github.com/cockroachdb/cockroach/pkg/security"
@@ -34,7 +32,6 @@ type stmtDiagnosticsRequest struct {
 type stmtDiagnostics struct {
 	ID                   int
 	StatementFingerprint string
-	Trace                string
 	CollectedAt          time.Time
 }
 
@@ -54,7 +51,6 @@ func (diagnostics *stmtDiagnostics) toProto() serverpb.StatementDiagnostics {
 		Id:                   int64(diagnostics.ID),
 		StatementFingerprint: diagnostics.StatementFingerprint,
 		CollectedAt:          diagnostics.CollectedAt,
-		Trace:                diagnostics.Trace,
 	}
 	return resp
 }
@@ -179,8 +175,7 @@ func (s *statusServer) StatementDiagnostics(
 		`SELECT
 			id,
 			statement_fingerprint,
-			collected_at,
-			trace
+			collected_at
 		FROM
 			system.statement_diagnostics
 		WHERE
@@ -207,19 +202,6 @@ func (s *statusServer) StatementDiagnostics(
 		diagnostics.CollectedAt = collectedAt.Time
 	}
 
-	if traceJSON, ok := row[3].(*tree.DJSON); ok {
-		traceJSONString, err := traceJSON.AsText()
-		if err != nil {
-			return nil, err
-		}
-		var prettyJSON bytes.Buffer
-		if err := json.Indent(
-			&prettyJSON, []byte(*traceJSONString), "" /* prefix */, "\t" /* indent */); err != nil {
-			return nil, errors.Wrap(err, "failed to parse JSON")
-		}
-		diagnostics.Trace = prettyJSON.String()
-	}
-
 	diagnosticsProto := diagnostics.toProto()
 	response := &serverpb.StatementDiagnosticsResponse{
 		Diagnostics: &diagnosticsProto,

pkg/server/status_test.go

@@ -2070,13 +2070,6 @@ func TestStatementDiagnosticsCompleted(t *testing.T) {
 	if err := getStatusJSONProto(s, diagPath, &diagRespGet); err != nil {
 		t.Fatal(err)
 	}
-
-	json := diagRespGet.Diagnostics.Trace
-	if json == "" ||
-		!strings.Contains(json, "traced statement") ||
-		!strings.Contains(json, "statement execution committed the txn") {
-		t.Fatal("statement diagnostics did not capture a trace")
-	}
 }
 
 func TestJobStatusResponse(t *testing.T) {

pkg/sql/catalog/systemschema/system.go

@@ -1593,6 +1593,7 @@ var (
 			{Name: "statement_fingerprint", ID: 2, Type: types.String, Nullable: false},
 			{Name: "statement", ID: 3, Type: types.String, Nullable: false},
 			{Name: "collected_at", ID: 4, Type: types.TimestampTZ, Nullable: false},
+			// TODO(radu): remove this column; it is no longer used.
 			{Name: "trace", ID: 5, Type: types.Jsonb, Nullable: true},
 			{Name: "bundle_chunks", ID: 6, Type: types.IntArray, Nullable: true},
 			{Name: "error", ID: 7, Type: types.String, Nullable: true},

pkg/sql/stmtdiagnostics/statement_diagnostics.go

@@ -401,9 +401,9 @@ func (r *Registry) InsertStatementDiagnostics(
 			ctx, "stmt-diag-insert", txn,
 			sessiondata.InternalExecutorOverride{User: security.RootUserName()},
 			"INSERT INTO system.statement_diagnostics "+
-				"(statement_fingerprint, statement, collected_at, trace, bundle_chunks, error) "+
-				"VALUES ($1, $2, $3, $4, $5, $6) RETURNING id",
-			stmtFingerprint, stmt, collectionTime, traceJSON, bundleChunksVal, errorVal,
+				"(statement_fingerprint, statement, collected_at, bundle_chunks, error) "+
+				"VALUES ($1, $2, $3, $4, $5) RETURNING id",
+			stmtFingerprint, stmt, collectionTime, bundleChunksVal, errorVal,
 		)
 		if err != nil {
 			return err

pkg/sql/stmtdiagnostics/statement_diagnostics_test.go

@@ -66,13 +66,6 @@ func TestDiagnosticsRequest(t *testing.T) {
 
 	checkCompleted(reqID)
 
-	// Check the trace.
-	row := db.QueryRow("SELECT jsonb_pretty(trace) FROM system.statement_diagnostics WHERE ID = $1", traceID.Int64)
-	var json string
-	require.NoError(t, row.Scan(&json))
-	require.Contains(t, json, "traced statement")
-	require.Contains(t, json, "statement execution committed the txn")
-
 	// Verify that we can handle multiple requests at the same time.
 	id1, err := registry.InsertRequestInternal(ctx, "INSERT INTO test VALUES (_)")
 	require.NoError(t, err)
@@ -139,13 +132,6 @@ func TestDiagnosticsRequestDifferentNode(t *testing.T) {
 			return nil
 		})
 		require.True(t, traceID.Valid)
-
-		// Check the trace.
-		row := db0.QueryRow(`SELECT jsonb_pretty(trace) FROM system.statement_diagnostics
-                         WHERE ID = $1`, traceID.Int64)
-		var json string
-		require.NoError(t, row.Scan(&json))
-		require.Contains(t, json, "traced statement")
 	}
 	runUntilTraced("INSERT INTO test VALUES (1)", reqID)
 

pkg/ui/src/views/reports/containers/statementDiagnosticsHistory/index.tsx

@@ -13,14 +13,12 @@ import { Helmet } from "react-helmet";
 import { connect } from "react-redux";
 import moment from "moment";
 import { Action, Dispatch } from "redux";
-import Long from "long";
 import { Link } from "react-router-dom";
 import { isUndefined } from "lodash";
 
 import { Anchor, Button, Text, TextTypes, Tooltip } from "src/components";
 import HeaderSection from "src/views/shared/components/headerSection";
 import { AdminUIState } from "src/redux/state";
-import { getStatementDiagnostics } from "src/util/api";
 import { trustIcon } from "src/util/trust";
 import DownloadIcon from "!!raw-loader!assets/download.svg";
 import {
@@ -36,7 +34,6 @@ import { DiagnosticStatusBadge } from "src/views/statements/diagnostics/diagnost
 import "./statementDiagnosticsHistoryView.styl";
 import { cockroach } from "src/js/protos";
 import IStatementDiagnosticsReport = cockroach.server.serverpb.IStatementDiagnosticsReport;
-import StatementDiagnosticsRequest = cockroach.server.serverpb.StatementDiagnosticsRequest;
 import {
   SortedTable,
   ColumnDescriptor,
@@ -205,19 +202,6 @@ class StatementDiagnosticsHistoryView extends React.Component<
     );
   };
 
-  getStatementDiagnostics = async (diagnosticsId: Long) => {
-    const request = new StatementDiagnosticsRequest({
-      statement_diagnostics_id: diagnosticsId,
-    });
-    const response = await getStatementDiagnostics(request);
-    const trace = response.diagnostics?.trace;
-    this.downloadRef.current?.download(
-      "statement-diagnostics.json",
-      "application/json",
-      trace,
-    );
-  };
-
   changeSortSetting = (ss: SortSetting) => {
     this.setState({
       sortSetting: ss,