From b30b932447d3ae059c0dac2c5bf0a3a79e0fa54e Mon Sep 17 00:00:00 2001
From: Xavier Noria <fxn@hashref.com>
Date: Fri, 25 Nov 2011 14:58:43 -0800
Subject: finders guide: adds some pointers to help users interpret the output
 of EXPLAIN

---
 railties/guides/source/active_record_querying.textile | 11 +++++++++++
 1 file changed, 11 insertions(+)

(limited to 'railties/guides/source/active_record_querying.textile')

diff --git a/railties/guides/source/active_record_querying.textile b/railties/guides/source/active_record_querying.textile
index 0f1f6eba4c..c4724f182e 100644
--- a/railties/guides/source/active_record_querying.textile
+++ b/railties/guides/source/active_record_querying.textile
@@ -1344,3 +1344,14 @@ EXPLAIN for: SELECT `posts`.* FROM `posts`  WHERE `posts`.`user_id` IN (1)
 </plain>
 
 under MySQL.
+
+h4. Interpreting EXPLAIN
+
+Interpretation of the output of EXPLAIN is beyond the scope of this guide. The
+following pointers may be helpful:
+
+* SQLite3: "EXPLAIN QUERY PLAN":http://www.sqlite.org/eqp.html
+
+* MySQL: "EXPLAIN Output Format":http://dev.mysql.com/doc/refman/5.6/en/explain-output.html
+
+* PostgreSQL: "Using EXPLAIN":http://www.postgresql.org/docs/current/static/using-explain.html
-- 
cgit v1.2.3

