MongoDB 哪些地方会产生锁？

最新推荐文章于 2024-06-08 09:15:00 发布

SAN_YUN

最新推荐文章于 2024-06-08 09:15:00 发布

阅读量772

点赞数

CC 4.0 BY-SA版权

分类专栏： mysql 文章标签：数据库 python javascript ViewUI

本文链接：https://blog.youkuaiyun.com/SAN_YUN/article/details/84385075

80 篇文章

订阅专栏

本文详细介绍了MongoDB中各种数据库操作所使用的锁类型。其中包括读锁和写锁的应用场景，如查询、获取更多数据、插入、删除及更新数据等操作。此外还探讨了特殊操作如Map-Reduce、创建索引及使用db.eval()和eval()命令时的锁行为。

Which operations lock the database?

原文：http://docs.mongodb.org/manual/faq/concurrency/#what-type-of-locking-does-mongodb-use

The following table lists common database operations and the types of locks they use.

Operation	Lock Type
Issue a query	Read lock
Get more data from a cursor	Read lock
Insert data	Write lock
Remove data	Write lock
Update data	Write lock
Map-reduce	Read lock and write lock, unless operations are specified as non-atomic. Portions of map-reduce jobs can run concurrently.
Create an index	Building an index in the foreground, which is the default, locks the database for extended periods of time.
`db.eval()`	Write lock. `db.eval()` blocks all other JavaScript processes.
`eval`	Write lock. If used with the `nolock` lock option, the `eval` option does not take a write lock and cannot write data to the database.
`aggregate()`	Read lock