Merge #40709

40709: sql: add a syntax hint for ALTER PARTITION r=solongordon a=solongordon

If a user tries to modify multiple index partitions via ALTER PARTITION
... OF TABLE, they now receive a hint to use ALTER PARTITION ... OF
INDEX instead.

I also improved the help docs for `\h ALTER PARTITION` to specify how to
use the wildcard syntax.

Fixes #40387

Release note: None

Co-authored-by: Solon Gordon <solon@cockroachlabs.com>

pkg/sql/parser/parse_test.go

@@ -2683,6 +2683,14 @@ DETAIL: source SQL:
 CREATE STATISTICS a ON col1 FROM t WITH OPTIONS AS OF SYSTEM TIME '-1s' THROTTLING 0.1 AS OF SYSTEM TIME '-2s'
                                                                                                               ^`,
 		},
+		{
+			`ALTER PARTITION p OF TABLE tbl@* CONFIGURE ZONE USING num_replicas = 1`,
+			`at or near "configure": syntax error: index wildcard unsupported in ALTER PARTITION ... OF TABLE
+DETAIL: source SQL:
+ALTER PARTITION p OF TABLE tbl@* CONFIGURE ZONE USING num_replicas = 1
+                                 ^
+HINT: try ALTER PARTITION <partition> OF INDEX <tablename>@*`,
+		},
 	}
 	for _, d := range testData {
 		t.Run(d.sql, func(t *testing.T) {

pkg/sql/parser/sql.y

@@ -1170,8 +1170,14 @@ alter_table_stmt:
 // ALTER PARTITION <name> <command>
 //
 // Commands:
-//   ALTER PARTITION ... OF TABLE ... CONFIGURE ZONE <zoneconfig>
-//   ALTER PARTITION ... OF INDEX ... CONFIGURE ZONE <zoneconfig>
+//   -- Alter a single partition which exists on any of a table's indexes.
+//   ALTER PARTITION <partition> OF TABLE <tablename> CONFIGURE ZONE <zoneconfig>
+//
+//   -- Alter a partition of a specific index.
+//   ALTER PARTITION <partition> OF INDEX <tablename>@<indexname> CONFIGURE ZONE <zoneconfig>
+//
+//   -- Alter all partitions with the same name across a table's indexes.
+//   ALTER PARTITION <partition> OF INDEX <tablename>@* CONFIGURE ZONE <zoneconfig>
 //
 // Zone configurations:
 //   DISCARD
@@ -1499,6 +1505,12 @@ alter_zone_partition_stmt:
     s.AllIndexes = true
     $$.val = s
   }
+| ALTER PARTITION partition_name OF TABLE table_name '@' '*' error
+  {
+    err := errors.New("index wildcard unsupported in ALTER PARTITION ... OF TABLE")
+    err = errors.WithHint(err, "try ALTER PARTITION <partition> OF INDEX <tablename>@*")
+    return setErr(sqllex, err)
+  }
 
 var_set_list:
   var_name '=' COPY FROM PARENT