#209 add tokudb_open_table_check_empty session variable to enable/disable may_table_be_open

storage/tokudb/ha_tokudb.cc

@@ -1732,7 +1732,7 @@ int ha_tokudb::initialize_share(
         init_auto_increment();
     }
 
-    if (may_table_be_empty(txn)) {
+    if (THDVAR(thd, open_table_check_empty) && may_table_be_empty(txn)) {
         share->try_table_lock = true;
     }
     else {

storage/tokudb/hatoku_hton.cc

@@ -1394,6 +1394,7 @@ static struct st_mysql_sys_var *tokudb_system_variables[] = {
     MYSQL_SYSVAR(loader_memory_size),
     MYSQL_SYSVAR(hide_default_row_format),
     MYSQL_SYSVAR(killed_time),
+    MYSQL_SYSVAR(open_table_check_empty),
     NULL
 };
 

storage/tokudb/hatoku_hton.h

@@ -484,6 +484,8 @@ static int tokudb_killed_callback(void) {
     return thd->killed;
 }
 
+static MYSQL_THDVAR_BOOL(open_table_check_empty, 0, "Check if table is empty at first open", NULL /*check*/, NULL /*update*/, true /*default*/);
+
 extern HASH tokudb_open_tables;
 extern pthread_mutex_t tokudb_mutex;
 extern uint32_t tokudb_write_status_frequency;