mysql - 随笔分类 - taek

php pdo prepare真的安全吗

摘要：详见这里 Let's say I have code like this: The PDO documentation says: Is that truly all I need to do to avoid SQL injections? Is it really that easy? You 阅读全文

posted @ 2018-10-25 16:38 taek 阅读(989) 评论(0) 推荐(0)

php prepare

摘要：详见 https://stackoverflow.com/questions/134099/are-pdo-prepared-statements-sufficient-to-prevent-sql-injection/12202218#12202218 php pdo prepare真的能防止sq 阅读全文

posted @ 2018-10-25 14:14 taek 阅读(472) 评论(0) 推荐(0)

mysql的联合索引的误解

摘要：https://www.zhihu.com/question/36996520 之前对于联合索引有一个误区，假设 name,age为一个联合索引 5条索引记录 a 10 b 5 c 12 c 15 d 2 当查找 where name='a' and age=10的时候能利用这个联合索引，为什么阅读全文

posted @ 2018-03-21 23:20 taek 阅读(407) 评论(0) 推荐(0)

inception_web

摘要：1) wget --no-check-certificate https://bootstrap.pypa.io/ez_setup.py 2) python ez_setup.py --insecure 3) wget https://pypi.python.org/packages/11/b6/a 阅读全文

posted @ 2017-07-10 10:31 taek 阅读(212) 评论(0) 推荐(0)

mysql优化器在统计全表扫描的代价时的方法

摘要：innodb 的聚集索引的叶子结点存放的是索引值以及数据页的偏移量那么在计算全表扫描的代价是怎么计算的呢？我们知道代价为 cpu代价+io代价 cpu代价就是每5条记录比对计算一个代价 (这里的记录并不是我们数据记录，而是索引记录) 是数据记录个数又是如何取出全表的总记录呢 ( 阅读全文

posted @ 2017-03-31 19:02 taek 阅读(1630) 评论(0) 推荐(0)

mysql 代价

摘要：mysql cbo cost base optimizer 基于代价，数据是一直变化的oracle8 以前是rbo rule base optimizer 基于规则, 如果sql使用了索引，必须使用索引,尽管全表扫描比索引快代价= cpu cost + io cost1)计算全表扫描代价 a)cp 阅读全文

posted @ 2017-03-28 18:42 taek 阅读(409) 评论(0) 推荐(1)

KEY

摘要：typedef struct st_key { uint key_length; /* Tot length of key */ ulong flags; /* dupp key and pack flags */ uint key_parts; /* How many ke... 阅读全文

posted @ 2016-02-25 15:11 taek 阅读(251) 评论(0) 推荐(0)

KEYUSE

摘要：typedef struct keyuse_t { TABLE *table; Item *val; /** equality condition is on *cond_guard == FALSE equality condition is off NULL - Otherwise (the sourc... 阅读全文

posted @ 2016-02-25 15:06 taek 阅读(193) 评论(0) 推荐(0)

class JOIN

摘要：class JOIN :public Sql_alloc { JOIN(const JOIN &rhs); /** *fields; List group_fields, group_fields_cache; TABLE *tmp_table; /// used to store 2 possible tmp table ... 阅读全文

posted @ 2016-02-05 11:42 taek 阅读(204) 评论(0) 推荐(0)

JOIN_TAB

摘要：typedef struct st_join_table { st_join_table() {} /* Remove gcc warning */ TABLE *table; KEYUSE *keyuse; /**select->quick. MySQL needs this i... 阅读全文

posted @ 2016-02-05 11:42 taek 阅读(247) 评论(0) 推荐(0)

gdb mysq

摘要：1.找到mysqld的id [root@default-tpl ~]# ps aux|grep mysqldroot 5006 0.0 0.0 103252 796 pts/6 S+ 15:15 0:00 grep mysqldmysql 27888 0.0 4.0 817168 47068 ? S 阅读全文

posted @ 2016-02-01 15:23 taek 阅读(221) 评论(0) 推荐(0)

浅谈B+树索引的分裂优化(转)

摘要：http://www.tamabc.com/article/85038.html 从MySQL Bug#67718浅谈B+树索引的分裂优化原文链接：http://hedengcheng.com/?p=525 问题背景今天，看到Twitter的DBA团队发布了其最新的MySQL分支：Changes 阅读全文

posted @ 2016-01-30 15:00 taek 阅读(2784) 评论(0) 推荐(1)

class JOIN

摘要：class JOIN :public Sql_alloc { JOIN(const JOIN &rhs); /** *fields; List group_fields, group_fields_cache; TABLE *tmp_table; /// used to store 2 possible tmp table ... 阅读全文

posted @ 2015-12-30 12:05 taek 阅读(224) 评论(0) 推荐(0)

结构体key

摘要：http://www.cnblogs.com/xpchild/p/3770823.html http://blog.sae.sina.com.cn/archives/3968 实例 http://blog.sae.sina.com.cn/archives/3968 http://www.cnblog 阅读全文

posted @ 2015-12-24 16:48 taek 阅读(436) 评论(0) 推荐(0)

create table

摘要：http://guduwhuzhe.iteye.com/blog/1887619 http://backend.wap.blog.163.com/w2/blogDetail.do?blogId=fks_0870660800950870710820830840680720840810650860950 阅读全文

posted @ 2015-12-24 16:01 taek 阅读(433) 评论(0) 推荐(0)

ha_innobase::open

摘要：http://mysql.taobao.org/monthly/2015/08/07/ 阅读全文

posted @ 2015-12-23 20:37 taek 阅读(385) 评论(0) 推荐(0)

mysql层的内存分配

摘要：参考 http://www.cnblogs.com/justfortaste/p/3198406.html http://m.blog.csdn.net/blog/IT_PCode/17007833 http://blog.chinaunix.net/uid-28364803-id-3419777. 阅读全文

posted @ 2015-12-20 18:02 taek 阅读(1390) 评论(0) 推荐(0)

mysql的插件式的存储引擎

摘要：转载 https://www.zhihu.com/question/19866767/answer/14942009 http://whuai.blog.51cto.com/3539000/862197 Oracle：数据文件包括：控制文件、数据文件、重做日志文件、参数文件、归档文件、密码文件。这阅读全文

posted @ 2015-12-18 23:29 taek 阅读(1172) 评论(0) 推荐(0)

ha_innobase::general_fetch

摘要：/***********************************************************************//** Reads the next or previous row from a cursor, which must have previously been positioned using index_read. @return 0,... 阅读全文

posted @ 2015-12-16 23:19 taek 阅读(347) 评论(0) 推荐(0)

ha_innobase::rnd_next

摘要：/*****************************************************************//** Reads the next row in a table scan (also used to read the FIRST row in a table scan). @return 0, HA_ERR_END_OF_FILE, or err... 阅读全文

posted @ 2015-12-12 00:02 taek 阅读(204) 评论(0) 推荐(0)

taek

随笔分类 - mysql

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