In this blog, we provide a comprehensive guide with practical examples of MySQL indexes. Explore MySQL CREATE INDEX, functional indexes and more in MySQL 8.0.
重建聚集索引和重定义主键都是很少发生,所以官方文档没有详细涉及如何recovery的过程,可能需要联系mysql service。 6.fast index creation的限制 在创建、删除过程要考虑下面因素: -创建索引时,文件会被写到临时目录($tmpdir)。要确保临时目录空间足够大 -如果一条alter table对同一个表进行drop index,add index,无法...
MySQL Worklogs are design specifications for changes that may define past work, or be considered for future development. WL#11808: Make the SPATIAL keyword optional in index creation Affects: Server-8.0 — Status: Complete Description Requirements High Level Architecture Currently, users have to speci...
Fast Index Creation工作原理 创建索引:对于辅助索引的创建,InnoDB会对创建索引的表加一个S锁。创建的过程中,不需要重建表,因此速度较之前提高很多,并且数据库的可用性也得到了提高 删除索引:删除辅助索引操作就更简单了,InnoDB只需更新内部视图,并将辅助索引的空间标记为可用,同时删除MySQL数据库内部视图上对该表的索...
Sorted index builds may result inoptimizerstatistics that differ from those generated by the previous method of index creation. The difference in statistics, which is not expected to affect workload performance, is due to the different algorithm used to populate the index....
Re: Index creation / Query Optimization : for a group by + SUM query on mysql Parttioned Table 673 Peter Brawley November 06, 2018 12:59PM Re: Index creation / Query Optimization : for a group by + SUM query on mysql Parttioned Table ...
[ERROR] 1071 - Specified key was too long; max key length is 3072 bytes This problem may occur in MySQL-8.0.20.5. Fault Analysis The InnoDB table engine has a length limit on index prefixes. By default, an index prefix can contain a maximum of 767 bytes, but ifinnodb_large_prefixis ...
原文链接:http://blog.inkernel.info/archives/15.html 之前认为MySQL可以进行在线增加索引,增加索引时会调用handler::add_index接口,但近期调试时发现,在调用add_index之前,MySQL会关闭所有的handler。因此怀疑可能在add_index期间表是不允许被操作的。InnoDB Plugin的文档说建secondary index时表是可读的,但是实际调试...
inbug#71708and Laurynas Biveinis even proved a patch to avoid autoinc_mutex creation for dummy table. Sincebug#71708is closed and I encountered this problem, I decide to open a new bug report.How to repeat:Under heavy io-intensive workload using MySQL5.6.19 In my test, using sysbench,...
In another attempt I created table with index and load 10M row at a time. All attempts show exponential behavior on index creation. I have tried other process monitor (gkrellm and top) . They all show memory is not the bottle neck and disk IO is heavy but not major cause, put CPU is...