Comment and test changes per review request by Timour. All tests pass on production with this code.

mysql-test/r/federated.result:
  added explain results to join test results per Timour's request.
mysql-test/t/federated.test:
  Added explain to test per Timour's request
sql/ha_federated.cc:
  better comment to explain why we need table->status set to 0

1 files changed, 31 insertions, 0 deletions

diff --git a/mysql-test/t/federated.test b/mysql-test/t/federated.test
index da8df543ed0..1e33efe1c0e 100644
--- a/mysql-test/t/federated.test
+++ b/mysql-test/t/federated.test
@@ -862,16 +862,32 @@ INSERT INTO federated.t1 (name, country_id, other) VALUES ('Monty', 4, 33333);
 INSERT INTO federated.t1 (name, country_id, other) VALUES ('Sanja', 5, 33333);
 
 #inner join
+EXPLAIN SELECT federated.t1.name AS name, federated.t1.country_id AS country_id,
+federated.t1.other AS other, federated.countries.country AS country 
+FROM federated.t1, federated.countries WHERE
+federated.t1.country_id = federated.countries.id;
+
 SELECT federated.t1.name AS name, federated.t1.country_id AS country_id,
 federated.t1.other AS other, federated.countries.country AS country 
 FROM federated.t1, federated.countries WHERE
 federated.t1.country_id = federated.countries.id;
 
+EXPLAIN SELECT federated.t1.name AS name, federated.t1.country_id AS country_id,
+federated.t1.other AS other, federated.countries.country AS country
+FROM federated.t1 INNER JOIN federated.countries ON
+federated.t1.country_id = federated.countries.id;
+
 SELECT federated.t1.name AS name, federated.t1.country_id AS country_id,
 federated.t1.other AS other, federated.countries.country AS country
 FROM federated.t1 INNER JOIN federated.countries ON
 federated.t1.country_id = federated.countries.id;
 
+EXPLAIN SELECT federated.t1.name AS name, federated.t1.country_id AS country_id,
+federated.t1.other AS other, federated.countries.country AS country
+FROM federated.t1 INNER JOIN federated.countries ON
+federated.t1.country_id = federated.countries.id
+WHERE federated.t1.name = 'Monty';
+
 SELECT federated.t1.name AS name, federated.t1.country_id AS country_id,
 federated.t1.other AS other, federated.countries.country AS country
 FROM federated.t1 INNER JOIN federated.countries ON
@@ -879,17 +895,32 @@ federated.t1.country_id = federated.countries.id
 WHERE federated.t1.name = 'Monty';
 
 #left join
+EXPLAIN SELECT federated.t1.*, federated.countries.country 
+FROM federated.t1 LEFT JOIN federated.countries 
+ON federated.t1.country_id = federated.countries.id
+ORDER BY federated.countries.id;
+
 SELECT federated.t1.*, federated.countries.country 
 FROM federated.t1 LEFT JOIN federated.countries 
 ON federated.t1.country_id = federated.countries.id
 ORDER BY federated.countries.id;
 
+EXPLAIN SELECT federated.t1.*, federated.countries.country 
+FROM federated.t1 LEFT JOIN federated.countries 
+ON federated.t1.country_id = federated.countries.id
+ORDER BY federated.countries.country;
+
 SELECT federated.t1.*, federated.countries.country 
 FROM federated.t1 LEFT JOIN federated.countries 
 ON federated.t1.country_id = federated.countries.id
 ORDER BY federated.countries.country;
 
 #right join
+EXPLAIN SELECT federated.t1.*, federated.countries.country 
+FROM federated.t1 RIGHT JOIN federated.countries 
+ON federated.t1.country_id = federated.countries.id 
+ORDER BY federated.t1.country_id;
+
 SELECT federated.t1.*, federated.countries.country 
 FROM federated.t1 RIGHT JOIN federated.countries 
 ON federated.t1.country_id = federated.countries.id