From 7e91991339283e73cdf1de429531c2a9114e44fa Mon Sep 17 00:00:00 2001
From: Jane Xing <zhouxing@uchicago.edu>
Date: Wed, 24 Aug 2022 10:37:42 -0500
Subject: [PATCH] sql: require txn-related metadata if running DDLs with
 internal executor with txn

When using internal executor to run DDL statements under a not-nil outer txn,
we require txn-related metadata (such as descriptor collections) to be passed
to the internal executor from the outer caller too. This commit is to add
a gate for this use case.

Release justification: bug fix
Release note: none
---
 pkg/sql/internal.go | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/pkg/sql/internal.go b/pkg/sql/internal.go
index 4091ea6f0980..738ad99f038c 100644
--- a/pkg/sql/internal.go
+++ b/pkg/sql/internal.go
@@ -817,6 +817,11 @@ func (ie *InternalExecutor) execInternal(
 	stmt string,
 	qargs ...interface{},
 ) (r *rowsIterator, retErr error) {
+	if ie.extraTxnState != nil {
+		if txn != ie.extraTxnState.txn {
+			return nil, errors.New("inconsistent txn with the one when constructing the internal executor")
+		}
+	}
 	ctx = logtags.AddTag(ctx, "intExec", opName)
 
 	var sd *sessiondata.SessionData
@@ -879,6 +884,11 @@ func (ie *InternalExecutor) execInternal(
 	timeReceived := timeutil.Now()
 	parseStart := timeReceived
 	parsed, err := parser.ParseOne(stmt)
+	if tree.CanModifySchema(parsed.AST) && txn != nil {
+		if ie.extraTxnState == nil || ie.extraTxnState.descCollection == nil {
+			return nil, errors.New("DDL statement is disallowed if internal executor is not bound with txn metadata")
+		}
+	}
 	if err != nil {
 		return nil, err
 	}