Mysql实例mysql缓冲和缓存设置详解

MYSQL实例
mysql> SHOW STATUS LIKE 'open%tables';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| Open_tables  | 5000 |
| Opened_tables | 195  |
+---------------+-------+
2 rows in set (0.00 sec)

MYSQL实例
mysql> SHOW STATUS LIKE 'threads%';
+-------------------+--------+
| Variable_name   | Value |
+-------------------+--------+
| Threads_cached  | 27   |
| Threads_connected | 15   |
| Threads_created  | 838610 |
| Threads_running  | 3   |
+-------------------+--------+
4 rows in set (0.00 sec)
 

MYSQL实例
mysql> show status like '%key_read%';
+-------------------+-----------+
| Variable_name   | Value   |
+-------------------+-----------+
| Key_read_requests | 163554268 |
| Key_reads     | 98247   |
+-------------------+-----------+
2 rows in set (0.00 sec)

MYSQL实例
mysql> SHOW STATUS LIKE 'created_tmp%';
+-------------------------+-------+
| Variable_name      | Value |
+-------------------------+-------+
| Created_tmp_disk_tables | 30660 |
| Created_tmp_files    | 2   |
| Created_tmp_tables   | 32912 |
+-------------------------+-------+
3 rows in set (0.00 sec)
 

MYSQL实例
mysql> SHOW STATUS LIKE "sort%";
+-------------------+---------+
| Variable_name   | Value  |
+-------------------+---------+
| Sort_merge_passes | 1    |
| Sort_range    | 79192  |
| Sort_rows     | 2066532 |
| Sort_scan     | 44006  |
+-------------------+---------+
4 rows in set (0.00 sec) 

MYSQL实例
mysql> SHOW STATUS LIKE "com_select";
+---------------+--------+
| Variable_name | Value |
+---------------+--------+
| Com_select  | 318243 |
+---------------+--------+
1 row in set (0.00 sec)
mysql> SHOW STATUS LIKE "handler_read_rnd_next";
+-----------------------+-----------+
| Variable_name     | Value   |
+-----------------------+-----------+
| Handler_read_rnd_next | 165959471 |
+-----------------------+-----------+
1 row in set (0.00 sec)

MYSQL实例
mysql> SHOW VARIABLES LIKE ‘%query_cache%';
+――――――――――+―――+
| Variable_name | Value |
+――――――――――+―――+
| have_query_cache | YES | C查询缓存是否可用
| query_cache_limit | 1048576 | C可缓存具体查询结果的最大值
| query_cache_min_res_unit | 4096 |
| query_cache_size | 599040 | C查询缓存的大小
| query_cache_type | ON | C阻止或是支持查询缓存
| query_cache_wlock_invalidate | OFF |
+――――――――――+―――+

MYSQL实例
# Query cache is used to cache SELECT results and later returnthem
# without actual executing the same query once again. Having thequery
# cache enabled may result in significant speed improvements, ifyour
# have a lot of identical queries and rarely changing tables.See the
# "Qcache_lowmem_prunes" status variable to check if the currentvalue
# is high enough for your load.
# Note: In case your tables change very often or if your queriesare
# textually different every time, the query cache may result ina
# slowdown instead of a performance improvement.
query_cache_size=0

MYSQL实例
query_cache_size=128M
query_cache_type=1

MYSQL实例
mysql> show variables like '%query_cache%';
+――――――――――+―――C+
| Variable_name      |Value  |
+――――――――――+―――C+
| have_query_cache     |YES   |
| query_cache_limit     |1048576  |
| query_cache_min_res_unit  |4096   |
| query_cache_size     | 134217728|
| query_cache_type     |ON    |
| query_cache_wlock_invalidate | OFF   |
+――――――――――+―――C+
6 rows in set (0.00 sec)

MYSQL实例
mysql> show status like '%Qcache%';
+――――――――-+―――C+
| Variable_name    |Value  |
+――――――――-+―――C+
| Qcache_free_blocks   |1    |
| Qcache_free_memory   | 134208800|
| Qcache_hits     |0    |