sql: guard against non-public mutation columns in CREATE STATISTICS

Defensively guard against non-public mutation columns when building
statistics requests for CREATE STATISTICS / ANALYZE.

Fixes: #118537

Release note: None

Author: michae2

pkg/sql/create_stats.go

@@ -420,6 +420,12 @@ func createStatsDefaultColumns(
 			return err
 		}
 
+		// There shouldn't be any non-public columns, but defensively skip over them
+		// if there are.
+		if !col.Public() {
+			return nil
+		}
+
 		// Skip unsupported virtual computed columns.
 		if isUnsupportedVirtual(col) {
 			return nil
@@ -466,9 +472,30 @@ func createStatsDefaultColumns(
 			continue
 		}
 
-		colIDs := make([]descpb.ColumnID, i+1)
+		colIDs := make([]descpb.ColumnID, 0, i+1)
 		for j := 0; j <= i; j++ {
-			colIDs[j] = desc.GetPrimaryIndex().GetKeyColumnID(j)
+			col, err := catalog.MustFindColumnByID(desc, desc.GetPrimaryIndex().GetKeyColumnID(j))
+			if err != nil {
+				return nil, err
+			}
+
+			// There shouldn't be any non-public columns, but defensively skip over
+			// them if there are.
+			if !col.Public() {
+				continue
+			}
+
+			// Skip unsupported virtual computed columns.
+			if isUnsupportedVirtual(col) {
+				continue
+			}
+			colIDs = append(colIDs, col.GetID())
+		}
+
+		// Do not attempt to create multi-column stats with < 2 columns. This can
+		// happen when an index contains only virtual computed columns.
+		if len(colIDs) < 2 {
+			continue
 		}
 
 		// Remember the requested stats so we don't request duplicates.
@@ -503,16 +530,23 @@ func createStatsDefaultColumns(
 				if err != nil {
 					return nil, err
 				}
+
+				// There shouldn't be any non-public columns, but defensively skip them
+				// if there are.
+				if !col.Public() {
+					continue
+				}
+
 				// Skip unsupported virtual computed columns.
 				if isUnsupportedVirtual(col) {
 					continue
 				}
 				colIDs = append(colIDs, col.GetID())
 			}
 
-			// Do not attempt to create multi-column stats with no columns. This
-			// can happen when an index contains only virtual computed columns.
-			if len(colIDs) == 0 {
+			// Do not attempt to create multi-column stats with < 2 columns. This can
+			// happen when an index contains only virtual computed columns.
+			if len(colIDs) < 2 {
 				continue
 			}
 

pkg/sql/logictest/testdata/logic_test/distsql_stats

@@ -2670,3 +2670,38 @@ upper_bound            range_rows  distinct_range_rows  equal_rows
 
 statement ok
 RESET enable_create_stats_using_extremes
+
+# Regression test for #118537. Do not create stats on non-public mutation
+# columns.
+statement ok
+CREATE TABLE t118537 (
+  a INT,
+  PRIMARY KEY (a) USING HASH WITH (bucket_count = 3)
+)
+
+statement ok
+INSERT INTO t118537 SELECT generate_series(0, 9)
+
+statement ok
+SET CLUSTER SETTING jobs.debug.pausepoints = 'newschemachanger.before.exec'
+
+skipif config local-legacy-schema-changer
+statement error job \d+ was paused before it completed with reason: pause point "newschemachanger.before.exec" hit
+ALTER TABLE t118537 ALTER PRIMARY KEY USING COLUMNS (a) USING HASH
+
+statement ok
+CREATE STATISTICS mutation FROM t118537
+
+query TTIB colnames
+SELECT statistics_name, column_names, row_count, histogram_id IS NOT NULL AS has_histogram
+FROM [SHOW STATISTICS FOR TABLE t118537]
+ORDER BY statistics_name, column_names::STRING
+----
+statistics_name  column_names  row_count  has_histogram
+mutation         {a}           10         true
+
+statement ok
+SET CLUSTER SETTING jobs.debug.pausepoints = ''
+
+statement ok
+RESUME JOB (SELECT job_id FROM crdb_internal.jobs WHERE description LIKE 'ALTER TABLE %t118537 ALTER PRIMARY KEY USING COLUMNS (a) USING HASH' AND status = 'paused' FETCH FIRST 1 ROWS ONLY)