我试图优化一个MySQL查询来加速Drupal视图。
这些表是节点,term_node和term_data。节点有大约500k行,term_node大约800k,term_data大约300k。
查询下方:
SELECT SQL_NO_CACHE DISTINCT(node.nid) AS nid
FROM drupal_node node
LEFT JOIN drupal_term_node term_node ON node.vid = term_node.vid
LEFT JOIN drupal_term_data term_data ON term_node.tid = term_data.tid
WHERE (node.status = 1) AND (node.type in ('foto_foto'))
AND (
(UPPER(term_data.name) LIKE UPPER('%Hanaa%') OR
UPPER(term_data.name) LIKE UPPER('%Bouchaib%')))
GROUP BY nid
LIMIT 0, 10;此查询需要大约11秒才能显示结果。
参与连接的所有列都被编入索引,以及term_data.name。
node.vid,term_node.vid,term_node.tid和term_data.tid是int(10),term_data.name是varchar(255)。
奇怪的是,运行这样的组合查询:
SELECT SQL_NO_CACHE DISTINCT(term_node.tid)
FROM drupal_term_data term_data
LEFT JOIN drupal_term_node term_node ON term_node.tid = term_data.tid
WHERE ((UPPER(term_data.name) LIKE UPPER('%Hanaa%')
OR UPPER(term_data.name) LIKE UPPER('%Bouchaib%')))
group by term_node.tid和
SELECT SQL_NO_CACHE DISTINCT(node.nid) AS nid
FROM drupal_node node
LEFT JOIN drupal_term_node term_node ON node.vid = term_node.vid
WHERE (node.status = 1) AND (node.type in ('foto_foto'))
GROUP BY nid第一次是0.23s,第二次是0.12s。所以我期望主查询至少应该在0.5s以下运行。这就像优化器没有在查询上运行一样。
我已经在涉及的表上运行了ANALYZE和OPTIMIZE,下面是EXPLAIN EXTENDED的结果。
*************************** 1. row ***************************
id: 1
select_type: SIMPLE
table: node
type: range
possible_keys: vid,node_status_type,node_type
key: node_status_type
key_len: 102
ref: NULL
rows: 496217
filtered: 100.00
Extra: Using where
*************************** 2. row ***************************
id: 1
select_type: SIMPLE
table: term_node
type: ref
possible_keys: PRIMARY,vid
key: vid
key_len: 4
ref: drupal_foto.node.vid
rows: 7
filtered: 100.00
Extra: Using where
*************************** 3. row ***************************
id: 1
select_type: SIMPLE
table: term_data
type: eq_ref
possible_keys: PRIMARY
key: PRIMARY
key_len: 4
ref: drupal_foto.term_node.tid
rows: 1
filtered: 100.00
Extra: Using where
3 rows in set, 1 warning (0.00 sec)该警告仅提供代码为1003的备注级别警告。