sql: support redaction of EXPLAIN (PLAN)

Support redaction of `EXPLAIN (PLAN)` and add plan.txt back to redacted
statement diagnostics bundles.

Part of: cockroachdb#68570

Epic: CRDB-19756

Release note (sql change): Add support for the `REDACT` flag to the
following variants of `EXPLAIN`:
- `EXPLAIN`
- `EXPLAIN (PLAN)`
- `EXPLAIN (VEC)`
- `EXPLAIN ANALYZE`
- `EXPLAIN ANALYZE (PLAN)`
These explain statements (along with `EXPLAIN ANALYZE (DEBUG)`, which
already supported `REDACT`) will have constants, literal values,
parameter values, and any other user data redacted in output.

pkg/sql/explain_bundle.go

@@ -310,10 +310,6 @@ func (b *stmtBundleBuilder) addOptPlans(ctx context.Context) {
 
 // addExecPlan adds the EXPLAIN (VERBOSE) plan as file plan.txt.
 func (b *stmtBundleBuilder) addExecPlan(plan string) {
-	if b.flags.RedactValues {
-		return
-	}
-
 	if plan == "" {
 		plan = "no plan"
 	}

pkg/sql/explain_bundle_test.go

@@ -300,7 +300,7 @@ CREATE TABLE users(id UUID DEFAULT gen_random_uuid() PRIMARY KEY, promo_id INT R
 					}
 				}
 				return nil
-			}, "env.sql schema.sql statement.sql vec.txt vec-v.txt",
+			}, "env.sql plan.txt schema.sql statement.sql vec-v.txt vec.txt",
 		)
 	})
 }

pkg/sql/opt/exec/explain/BUILD.bazel

@@ -39,6 +39,7 @@ go_library(
         "//pkg/util/timeutil",
         "//pkg/util/treeprinter",
         "@com_github_cockroachdb_errors//:errors",
+        "@com_github_cockroachdb_redact//:redact",
         "@com_github_dustin_go_humanize//:go-humanize",
     ],
 )

pkg/sql/opt/exec/explain/emit.go

@@ -76,7 +76,14 @@ func Emit(plan *Plan, ob *OutputBuilder, spanFormatFn SpanFormatFn) error {
 		// This field contains the original subquery (which could have been modified
 		// by optimizer transformations).
 		if s.ExprNode != nil {
-			ob.Attr("original sql", tree.AsStringWithFlags(s.ExprNode, tree.FmtSimple))
+			flags := tree.FmtSimple
+			if e.ob.flags.HideValues {
+				flags |= tree.FmtHideConstants
+			}
+			if e.ob.flags.RedactValues {
+				flags |= tree.FmtMarkRedactionNode | tree.FmtOmitNameRedaction
+			}
+			ob.Attr("original sql", tree.AsStringWithFlags(s.ExprNode, flags))
 		}
 		var mode string
 		switch s.Mode {
@@ -1006,7 +1013,8 @@ func (e *emitter) spansStr(table cat.Table, index cat.Index, scanParams exec.Sca
 	}
 
 	// In verbose mode show the physical spans, unless the table is virtual.
-	if e.ob.flags.Verbose && !table.IsVirtualTable() {
+	if e.ob.flags.Verbose && !e.ob.flags.HideValues && !e.ob.flags.RedactValues &&
+		!table.IsVirtualTable() {
 		return e.spanFormatFn(table, index, scanParams)
 	}
 
@@ -1017,8 +1025,8 @@ func (e *emitter) spansStr(table cat.Table, index cat.Index, scanParams exec.Sca
 		return fmt.Sprintf("%d span%s", n, util.Pluralize(int64(n)))
 	}
 
-	// If we must hide values, only show the count.
-	if e.ob.flags.HideValues {
+	// If we must hide or redact values, only show the count.
+	if e.ob.flags.HideValues || e.ob.flags.RedactValues {
 		n := scanParams.IndexConstraint.Spans.Count()
 		return fmt.Sprintf("%d span%s", n, util.Pluralize(int64(n)))
 	}

pkg/sql/opt/exec/explain/output.go

@@ -22,6 +22,7 @@ import (
 	"github.com/cockroachdb/cockroach/pkg/util/humanizeutil"
 	"github.com/cockroachdb/cockroach/pkg/util/treeprinter"
 	"github.com/cockroachdb/errors"
+	"github.com/cockroachdb/redact"
 )
 
 // OutputBuilder is used to build the output of an explain tree.
@@ -148,6 +149,9 @@ func (ob *OutputBuilder) Expr(key string, expr tree.TypedExpr, varColumns colinf
 	if ob.flags.HideValues {
 		flags |= tree.FmtHideConstants
 	}
+	if ob.flags.RedactValues {
+		flags |= tree.FmtMarkRedactionNode | tree.FmtOmitNameRedaction
+	}
 	f := tree.NewFmtCtx(
 		flags,
 		tree.FmtIndexedVarFormat(func(ctx *tree.FmtCtx, idx int) {
@@ -210,7 +214,11 @@ func (ob *OutputBuilder) BuildStringRows() []string {
 		}
 		// Add any fields for the node.
 		for entry = popField(); entry != nil; entry = popField() {
-			child.AddLine(entry.fieldStr())
+			field := entry.fieldStr()
+			if ob.flags.RedactValues {
+				field = string(redact.RedactableString(field).Redact())
+			}
+			child.AddLine(field)
 		}
 	}
 	result = append(result, tp.FormattedRows()...)

pkg/sql/sem/tree/explain.go

@@ -264,10 +264,14 @@ func MakeExplain(options []string, stmt Statement) (Statement, error) {
 	}
 
 	if opts.Flags[ExplainFlagRedact] {
-		// TODO(michae2): Support redaction of other EXPLAIN variants.
-		if !analyze || opts.Mode != ExplainDebug {
-			return nil, unimplemented.New(
-				"EXPLAIN (REDACT)", "the REDACT flag can only be used with EXPLAIN ANALYZE (DEBUG)",
+		// TODO(michae2): Support redaction of other EXPLAIN modes.
+		switch opts.Mode {
+		case ExplainPlan:
+		case ExplainVec:
+		case ExplainDebug:
+		default:
+			return nil, unimplemented.Newf(
+				"EXPLAIN (REDACT)", "the REDACT flag cannot be used with %s", opts.Mode,
 			)
 		}
 	}