提交读，未提交读，可重复读，可串行读。

Read committed, Read uncommitted, Repeatable Read, Serializable.

youdao

比如，读取只读的查找表不需要可重复读级别，未提交读级别就足够了。

For example, reading from a read - only look up table doesn t require repeatable read, and uncommitted read is sufficient.

youdao

支持表级和行级锁以及4个隔离级别：RR(可重复读)、RS(读可靠)、CS(默认——游标可靠)和UR(未提交读)。

Supports table and row level locking and 4 isolation levels, RR (repeatable read), rs (read stability), CS (default - cursor stability) and ur (uncommitted read).

youdao