Suppress Gap Lock errors for unique key lookups

Summary:
Non primary unique key locking lookup was logged to Gap Lock
logs (or returned as errors if setting gap_lock_raise_error=1).
This was wrong. This diff covers unique key as well.

squash with: https://reviews.facebook.net/D54813

Test Plan: mtr

Reviewers: jkedgar, spetrunia, mung, hermanlee4

Reviewed By: hermanlee4

Subscribers: webscalesql-eng

Differential Revision: https://reviews.facebook.net/D62139

mysql-test/include/gap_lock_raise_error_select.inc

@@ -42,7 +42,6 @@ eval select * from gap1 order by id1 desc, id2 desc, id3 desc
 --error ER_UNKNOWN_ERROR
 eval select * from gap1 force index(i) where c1=1 $select_lock;
 # unique index lookup
---error ER_UNKNOWN_ERROR
 eval select * from gap3 force index(ui) where value=1 $select_lock;
 # primary key lookup
 eval select * from gap1 where id1=1 and id2=1 and id3=1 $select_lock;

mysql-test/include/gap_lock_raise_error_update.inc

@@ -64,3 +64,25 @@ select * from gap1, gap2 limit 1 for update;
 --error ER_UNKNOWN_ERROR
 select * from gap1 a, gap1 b limit 1 for update;
 
+# unique secondary key
+create table u1(
+ c1 int,
+ c2 int,
+ c3 int,
+ c4 int,
+ primary key (c1, c2, c3),
+ unique key (c3, c1)
+);
+set session gap_lock_raise_error=1;
+begin;
+insert into u1 values (1,1,1,1);
+commit;
+begin;
+insert into u1 values (1,2,1,1) on duplicate key update c4=10;
+commit;
+begin;
+select * from u1 where c3=1 and c1 = 1 for update;
+--error ER_UNKNOWN_ERROR
+select * from u1 where c3=1 for update;
+commit;
+drop table u1;

mysql-test/r/gap_lock_option.result

@@ -12,6 +12,6 @@ gap_lock_exceptions	t2
 set session gap_lock_raise_error=1;
 begin;
 delete from t1 where id=1;
-ERROR HY000: Using Gap Lock without full primary key in multi-table or multi-statement transactions is not allowed. You need either 1: Execute 'SET SESSION gap_lock_raise_error=0' if you are sure that your application does not rely on Gap Lock. 2: Rewrite queries to use all primary key columns in WHERE equal conditions. 3: Rewrite to single-table, single-statement transaction.  Query: delete from t1 where id=1
+ERROR HY000: Using Gap Lock without full unique key in multi-table or multi-statement transactions is not allowed. You need either 1: Execute 'SET SESSION gap_lock_raise_error=0' if you are sure that your application does not rely on Gap Lock. 2: Rewrite queries to use all unique key columns in WHERE equal conditions. 3: Rewrite to single-table, single-statement transaction.  Query: delete from t1 where id=1
 commit;
 drop table t1;

mysql-test/suite/rocksdb/r/gap_lock_issue254.result

@@ -4,6 +4,6 @@ update t set value=100 where id in (1, 2);
 commit;
 begin;
 select * from t for update;
-ERROR HY000: Using Gap Lock without full primary key in multi-table or multi-statement transactions is not allowed. You need either 1: Execute 'SET SESSION gap_lock_raise_error=0' if you are sure that your application does not rely on Gap Lock. 2: Rewrite queries to use all primary key columns in WHERE equal conditions. 3: Rewrite to single-table, single-statement transaction.  Query: select * from t for update
+ERROR HY000: Using Gap Lock without full unique key in multi-table or multi-statement transactions is not allowed. You need either 1: Execute 'SET SESSION gap_lock_raise_error=0' if you are sure that your application does not rely on Gap Lock. 2: Rewrite queries to use all unique key columns in WHERE equal conditions. 3: Rewrite to single-table, single-statement transaction.  Query: select * from t for update
 commit;
 drop table t;

sql/handler.cc

@@ -2978,7 +2978,7 @@ int handler::ha_index_read_map(uchar *buf, const uchar *key,
               m_lock_type != F_UNLCK);
   DBUG_ASSERT(inited == INDEX);
 
-  if (is_using_prohibited_gap_locks(table, is_using_full_primary_key(
+  if (is_using_prohibited_gap_locks(table, is_using_full_unique_key(
                                       active_index, keypart_map, find_flag)))
   {
     DBUG_RETURN(HA_ERR_LOCK_DEADLOCK);
@@ -3024,7 +3024,7 @@ int handler::ha_index_read_idx_map(uchar *buf, uint index, const uchar *key,
               m_lock_type != F_UNLCK);
   DBUG_ASSERT(end_range == NULL);
 
-  if (is_using_prohibited_gap_locks(table, is_using_full_primary_key(
+  if (is_using_prohibited_gap_locks(table, is_using_full_unique_key(
                                       index, keypart_map, find_flag)))
   {
     return HA_ERR_LOCK_DEADLOCK;
@@ -3122,17 +3122,17 @@ bool handler::is_using_full_key(key_part_map keypart_map,
                         - 1));
 }
 
-bool handler::is_using_full_primary_key(uint index,
+bool handler::is_using_full_unique_key(uint index,
                                         key_part_map keypart_map,
                                         enum ha_rkey_function find_flag)
 {
   return (is_using_full_key(keypart_map,
                             table->key_info[index].actual_key_parts)
-          && index == table->s->primary_key
-          && find_flag == HA_READ_KEY_EXACT);
+          && find_flag == HA_READ_KEY_EXACT
+          && (index == table->s->primary_key
+              || (table->key_info[index].flags & HA_NOSAME)));
 }
 
-
 /**
   Reads the last row via index.
 
@@ -7956,13 +7956,13 @@ bool handler::is_using_prohibited_gap_locks(TABLE *table,
     if (thd->variables.gap_lock_raise_error)
     {
       my_printf_error(ER_UNKNOWN_ERROR,
-                      "Using Gap Lock without full primary key in multi-table "
+                      "Using Gap Lock without full unique key in multi-table "
                       "or multi-statement transactions is not "
                       "allowed. You need either 1: Execute 'SET SESSION "
                       "gap_lock_raise_error=0' if you are sure that "
                       "your application does not rely on Gap Lock. "
                       "2: Rewrite queries to use "
-                      "all primary key columns in WHERE equal conditions. "
+                      "all unique key columns in WHERE equal conditions. "
                       "3: Rewrite to single-table, single-statement "
                       "transaction.  Query: %s",
                       MYF(0), thd->query());

sql/handler.h

@@ -2446,11 +2446,11 @@ class handler :public Sql_alloc
     return index_read_last(buf, key, key_len);
   }
   bool is_using_full_key(key_part_map keypart_map, uint actual_key_parts);
-  bool is_using_full_primary_key(uint active_index,
+  bool is_using_full_unique_key(uint active_index,
                                  key_part_map keypart_map,
                                  enum ha_rkey_function find_flag);
   bool is_using_prohibited_gap_locks(TABLE *table,
-                                     bool using_full_primary_key);
+                                     bool using_full_unique_key);
 public:
   virtual int read_range_first(const key_range *start_key,
                                const key_range *end_key,

storage/rocksdb/ha_rocksdb.cc

@@ -5774,7 +5774,7 @@ int ha_rocksdb::read_range_first(const key_range *start_key,
   else
   {
     if (is_using_prohibited_gap_locks(table,
-                                      is_using_full_primary_key(
+                                      is_using_full_unique_key(
                                         active_index,
                                         start_key->keypart_map,
                                         start_key->flag)))