EXPLAIN FORMAT=JSON

Add support for semi-join strategies: FirstMatch, DuplicateWeedout,
LooseScan.

1 files changed, 72 insertions, 0 deletions

diff --git a/mysql-test/r/explain_json.result b/mysql-test/r/explain_json.result
index 4a45e8d7594..c159161a8bd 100644
--- a/mysql-test/r/explain_json.result
+++ b/mysql-test/r/explain_json.result
@@ -592,5 +592,77 @@ EXPLAIN
     }
   }
 }
+# 
+# First-Match
+# 
+explain
+select * from t2 where t2.a in ( select a from t1 where t1.b=t2.b);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	10	
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	10	Using where; FirstMatch(t2); Using join buffer (flat, BNL join)
+explain format=json
+select * from t2 where t2.a in ( select a from t1 where t1.b=t2.b);
+EXPLAIN
+{
+  "query_block": {
+    "select_id": 1,
+    "table": {
+      "table_name": "t2",
+      "access_type": "ALL",
+      "rows": 10,
+      "filtered": 100
+    },
+    "block-nl-join": {
+      "table": {
+        "table_name": "t1",
+        "access_type": "ALL",
+        "rows": 10,
+        "filtered": 100,
+        "first_match": "t2"
+      },
+      "buffer_type": "flat",
+      "join_type": "BNL",
+      "attached_condition": "((t1.b = t2.b) and (t1.a = t2.a))"
+    }
+  }
+}
+# 
+# Duplicate Weedout
+# 
+set @tmp= @@optimizer_switch;
+set optimizer_switch='firstmatch=off';
+explain
+select * from t2 where t2.a in ( select a from t1 where t1.b=t2.b);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	10	
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	10	Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
+explain format=json
+select * from t2 where t2.a in ( select a from t1 where t1.b=t2.b);
+EXPLAIN
+{
+  "query_block": {
+    "select_id": 1,
+    "table": {
+      "table_name": "t2",
+      "access_type": "ALL",
+      "rows": 10,
+      "filtered": 100
+    },
+    "duplicates_removal": {
+      "block-nl-join": {
+        "table": {
+          "table_name": "t1",
+          "access_type": "ALL",
+          "rows": 10,
+          "filtered": 100
+        },
+        "buffer_type": "flat",
+        "join_type": "BNL",
+        "attached_condition": "((t1.b = t2.b) and (t1.a = t2.a))"
+      }
+    }
+  }
+}
+set optimizer_switch=@tmp;
 drop table t1,t2;
 drop table t0;