migrations: drop idx_paths_path

idx_paths_path is a duplicate of index paths_path_module_id_key and is dropped.

This frees up 16 GB of index space.

For golang/go#39629

Change-Id: Ia6baa1c47a00c2724ab85274787d68befc5ac92d
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/265247
Trust: Julie Qiu <[email protected]>
Run-TryBot: Julie Qiu <[email protected]>
TryBot-Result: kokoro <[email protected]>
Reviewed-by: Jamal Carvalho <[email protected]>

Author: julieqiu

migrations/000041_drop_idx_paths_path.down.sql

@@ -0,0 +1,11 @@
+-- Copyright 2020 The Go Authors. All rights reserved.
+-- Use of this source code is governed by a BSD-style
+-- license that can be found in the LICENSE file.
+
+BEGIN;
+
+CREATE INDEX idx_paths_path ON paths (path);
+COMMENT ON INDEX idx_paths_path is
+'INDEX idx_paths_path is used to get path information from a path.';
+
+END;

migrations/000041_drop_idx_paths_path.up.sql

@@ -0,0 +1,9 @@
+-- Copyright 2020 The Go Authors. All rights reserved.
+-- Use of this source code is governed by a BSD-style
+-- license that can be found in the LICENSE file.
+
+BEGIN;
+
+DROP INDEX idx_paths_path;
+
+END;