Indexes with boolean values (#31)

* mfvanek/pg-index-health#322

Query to check on indexes with boolean values.

* mfvanek/pg-index-health#322

Fix formatting.
Add header and description.

sql/indexes_with_boolean.sql

@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2019-2024. Ivan Vakhrushev and others.
+ * https://github.com/mfvanek/pg-index-health-sql
+ *
+ * Licensed under the Apache License 2.0
+ */
+
+-- Finds indexes that contains boolean values.
+select
+    pi.indrelid::regclass::text as table_name,
+    pi.indexrelid::regclass::text as index_name,
+    col.attname as column_name,
+    col.attnotnull as column_not_null
+from
+    pg_catalog.pg_index pi
+    join pg_catalog.pg_class pc on pc.oid = pi.indexrelid
+    join pg_catalog.pg_namespace pn on pn.oid = pc.relnamespace
+    join pg_catalog.pg_attribute col on col.attrelid = pi.indrelid and col.attnum = any(pi.indkey)
+where pn.nspname = :schema_name_param::text
+  and not pi.indisunique
+  and pi.indisready
+  and pi.indisvalid
+  and col.atttypid = 'boolean'::regtype
+order by table_name, index_name;