(Feat): Initial Commit

scripts/sql/fk_missing_index.sql

@@ -0,0 +1,57 @@
+-- Errors if FKs do not have an index
+CREATE OR REPLACE FUNCTION fk_missing_index ()
+    RETURNS void
+    AS $$
+DECLARE
+    item record;
+BEGIN
+    FOR item IN
+    SELECT
+        c.conrelid::regclass AS "table",
+        /* list of key column names in order */
+        string_agg(a.attname, ',' ORDER BY x.n) AS columns,
+        pg_catalog.pg_size_pretty(pg_catalog.pg_relation_size(c.conrelid)) AS size,
+        c.conname AS constraint,
+        c.confrelid::regclass AS referenced_table
+    FROM
+        pg_catalog.pg_constraint c
+        /* enumerated key column numbers per foreign key */
+    CROSS JOIN LATERAL unnest(c.conkey)
+    WITH ORDINALITY AS x (attnum, n)
+    /* name for each key column */
+    JOIN pg_catalog.pg_attribute a ON a.attnum = x.attnum
+        AND a.attrelid = c.conrelid
+WHERE
+    NOT EXISTS
+    /* is there a matching index for the constraint? */
+    (
+        SELECT
+            1
+        FROM
+            pg_catalog.pg_index i
+        WHERE
+            i.indrelid = c.conrelid
+            /* the first index columns must be the same as the
+             key columns, but order doesn't matter */
+            AND (i.indkey::smallint[])[0:cardinality(c.conkey) - 1] @> c.conkey)
+        AND c.contype = 'f'
+    GROUP BY
+        c.conrelid,
+        c.conname,
+        c.confrelid
+    ORDER BY
+        pg_catalog.pg_relation_size(c.conrelid) DESC LOOP
+            RAISE WARNING 'CREATE INDEX "idx_%_fk_%" ON "%" ("%");', item.table, item.columns, item.table, item.columns USING HINT = to_json(item);
+        END LOOP;
+    IF FOUND THEN
+        RAISE EXCEPTION ' We require ALL FOREIGN keys TO have an INDEX defined. ';
+    END IF;
+END;
+$$
+LANGUAGE plpgsql;
+
+SELECT
+    *
+FROM
+    fk_missing_index ();
+