From 5eb35aafb9dfbc33da2f6d7cd5f47511751ee333 Mon Sep 17 00:00:00 2001
From: Faizan Qazi <faizan@cockroachlabs.com>
Date: Mon, 8 Aug 2022 09:38:41 -0400
Subject: [PATCH] sql/randgen: avoid invalid inverted indexes in CREATE TABLE

Previously, the create table made via the randgen component
could create invalid CREATE TABLE statements where the last
columns of an inverted index were descending. This could
lead to unexpected failures in certain workloads, which
expected valid statements from this components. To address
this, this patch stops randgen from generating CREATE table
statements with invalid inverted indexes.

Release note: None
---
 pkg/sql/randgen/schema.go | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/pkg/sql/randgen/schema.go b/pkg/sql/randgen/schema.go
index 2d6d2f6de08d..587e21b3a36d 100644
--- a/pkg/sql/randgen/schema.go
+++ b/pkg/sql/randgen/schema.go
@@ -189,6 +189,10 @@ func RandCreateTableWithColumnIndexNumberGenerator(
 			if foundOverlap {
 				continue
 			}
+			// Inverted indexes can only be ascending on the last column.
+			if col.Direction == tree.Descending {
+				continue
+			}
 		}
 		// Make forward indexes unique 50% of the time. Inverted indexes cannot
 		// be unique.