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如何改进我的选择查询?目前以下选择查询需要大约 2 分钟才能执行。

SELECT COUNT( * ) AS count
FROM post
WHERE category REGEXP  '[[:<:]](5|50|51|52|53|54|55|56|57|58|59|60|61|62|63|64|65|66|67|68|69|70|71|72|73|74|75|76|77|78|79|80|81|82|83|84|85|86|87|88|89|90|91|92|93|94|95|96|97|98|99|100|101|102|103|104|105|106|107|108|109|110|111|112|113|114|115|116|117|118|119|120|121|122|123|124|125|126|127|128|129|130|131|132|133|134|135|136|137|138|139|140|141|142|143|144|145|146|147|148|149|150|151|152|153|154|155|156|157|158|159|160|161|162|163|164|165|166|167|168|169|170|171|172|173|174|175|176|177|178|179|180|181|182|183|184|185|186|187|188|189|190|191|192|193|194|195|196|197|198|199|200|201|202|203|204|205|206|207|208|209|210|211|212|213|214|215|216|217|218|219|220|221|222|223|224|225|226|227|228|229|230|231|232|233|234|235|236|237)[[:>:]]'
AND approve =1

 +-------+
| count |
+-------+
| 12718 |
+-------+
1 row in set (2 min 12.68 sec)

mysql> explain SELECT COUNT( * ) AS count   FROM post   WHERE category REGEXP  '[[:<:]](5|50|51|52|53|54|55|56|57|58|59|60|61|62|63|64|65|66|67|68|69|70|71|72|73|74|75|76|77|78|79|80|81|82|83|84|85|86|87|88|89|90|91|92|93|94|95|96|97|98|99|100|101|102|103|104|105|106|107|108|109|110|111|112|113|114|115|116|117|118|119|120|121|122|123|124|125|126|127|128|129|130|131|132|133|134|135|136|137|138|139|140|141|142|143|144|145|146|147|148|149|150|151|152|153|154|155|156|157|158|159|160|161|162|163|164|165|166|167|168|169|170|171|172|173|174|175|176|177|178|179|180|181|182|183|184|185|186|187|188|189|190|191|192|193|194|195|196|197|198|199|200|201|202|203|204|205|206|207|208|209|210|211|212|213|214|215|216|217|218|219|220|221|222|223|224|225|226|227|228|229|230|231|232|233|234|235|236|237)[[:>:]]' AND approve =1;
+----+-------------+----------+------+---------------+---------+---------+-------+--------+-------------+
| id | select_type | table    | type | possible_keys | key     | key_len | ref   | rows   | Extra       |
+----+-------------+----------+------+---------------+---------+---------+-------+--------+-------------+
|  1 | SIMPLE      | post | ref  | approve       | approve | 1       | const | 844258 | Using where |
+----+-------------+----------+------+---------------+---------+---------+-------+--------+-------------+

服务器版本:5.6.12-56 Percona Server (GPL),Release rc60.4,Revision 393

查询缓存已启用。

mysql> show variables like "query%"
    -> ;
+------------------------------+-----------+
| Variable_name                | Value     |
+------------------------------+-----------+
| query_alloc_block_size       | 8192      |
| query_cache_limit            | 10485760  |
| query_cache_min_res_unit     | 4096      |
| query_cache_size             | 536870912 |
| query_cache_strip_comments   | OFF       |
| query_cache_type             | ON        |
| query_cache_wlock_invalidate | OFF       |
| query_prealloc_size          | 8192      |
+------------------------------+-----------+
+-------------------------+-----------+
| Variable_name           | Value     |
+-------------------------+-----------+
| Qcache_free_blocks      | 29707     |
| Qcache_free_memory      | 297925216 |
| Qcache_hits             | 2799738   |
| Qcache_inserts          | 779490    |
| Qcache_lowmem_prunes    | 0         |
| Qcache_not_cached       | 256026    |
| Qcache_queries_in_cache | 110396    |
| Qcache_total_blocks     | 253234    |
+-------------------------+-----------+
4

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