Mysql-tuning

mysql performance tuning

query cache example

mysql> show status like "%Qcache%";
+-------------------------+----------+
| Variable_name           | Value    |
+-------------------------+----------+
| Qcache_free_blocks      | 1        |
| Qcache_free_memory      | 18481592 |
| Qcache_hits             | 82184    |
| Qcache_inserts          | 50875    |
| Qcache_lowmem_prunes    | 0        | #should be like 0 if not, chache size is too small
| Qcache_not_cached       | 28127    |
| Qcache_queries_in_cache | 22048    |
| Qcache_total_blocks     | 44200    |
+-------------------------+----------+
8 rows in set (0.03 sec)

in the table variables is a opportunity to set some values:

mysql> show variables like "%query_cache%";
+------------------------------+----------+
| Variable_name                | Value    |
+------------------------------+----------+
| have_query_cache             | YES      |
| query_cache_limit            | 1048576  |
| query_cache_min_res_unit     | 4096     |
| query_cache_size             | 41943040 |
| query_cache_type             | ON       |
| query_cache_wlock_invalidate | OFF      |
+------------------------------+----------+
6 rows in set (0.00 sec)