Server Status Variables The number of joins without keys that check for key usage after each row. If this is not 0, you should carefully check the indexes of your tables. • Select_scan • Slave_open_temp_tables The number of joins that did a full scan of the first table. The number of temporary tables that the replication SQL thread currently has open. If the value is greater than zero, it is not safe to shut down the replica; see Section 17.5.1.31, “Replication and Temporary Tables” . This variable reports the total count of open temporary tables for  all  replication channels. The search algorithm that was most recently used by this replica to locate rows for row-based replication. The result shows whether the replica used indexes, a table scan, or hashing as the search algorithm for the last transaction executed on any channel. The method used depends on the setting for the  slave_rows_search_algorithms  system variable, and the keys that are available on the relevant table. This variable is available only for debug builds of MySQL. • Slave_rows_last_search_algorithm_used • Slow_launch_threads The number of threads that have taken more than  slow_launch_time  seconds to create. The number of queries that have taken more than  long_query_time  seconds. This counter increments regardless of whether the slow query log is enabled. For information about that log, see Section 5.4.5, “The Slow Query Log” . The number of merge passes that the sort algorithm has had to do. If this value is large, you should consider increasing the value of the  sort_buffer_size  system variable. • Slow_queries • Sort_merge_passes • Sort_range The number of sorts that were done using ranges. The number of sorted rows. The number of sorts that were done by scanning the table. The number of negotiates needed to establish the connection. • Sort_rows • Sort_scan • Ssl_accept_renegotiates • Ssl_accepts 966