Adjust psql \d query to avoid use of @> operator.

tglsfdc · tglsfdc · commit 471d55859c11 · 2017-10-22T16:45:16.000-04:00
It seems that the parray_gin extension has seen fit to introduce a "text[] @> text[]" operator, which conflicts with the core "anyarray @> anyarray" operator, causing ambiguous-operator failures if the input arguments are coercible to text[] without being exactly that type. This strikes me as a bad idea, but it's out there and people use it. As of v10, that breaks psql's query that tries to test "pg_statistic_ext.stxkind @> '{d}'", since stxkind is char[]. The best workaround seems to be to avoid use of that operator. We can use a scalar-vs-array test "'d' = any(stxkind)" instead; that's arguably more readable anyway. Per report from Justin Pryzby. Backpatch to v10 where this query was added. Discussion: https://postgr.es/m/20171022181525.GA21884@telsasoft.com
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
@@ -2423,8 +2423,8 @@ describeOneTableDetails(const char *schemaname,
 							  "   FROM pg_catalog.unnest(stxkeys) s(attnum)\n"
 							  "   JOIN pg_catalog.pg_attribute a ON (stxrelid = a.attrelid AND\n"
 							  "        a.attnum = s.attnum AND NOT attisdropped)) AS columns,\n"
-							  "  (stxkind @> '{d}') AS ndist_enabled,\n"
-							  "  (stxkind @> '{f}') AS deps_enabled\n"
+							  "  'd' = any(stxkind) AS ndist_enabled,\n"
+							  "  'f' = any(stxkind) AS deps_enabled\n"
 							  "FROM pg_catalog.pg_statistic_ext stat "
 							  "WHERE stxrelid = '%s'\n"
 							  "ORDER BY 1;",
