Database Reads

Committed Read : Data can only be read when a transaction is complete. i.e Data cannot be read in the middle

Uncommitted Read: Data can be read even in the middle of a transaction i.e even when it’s not saved. Also called “Dirty Read”

SQL Server - default is COMMITTED READ
PGSQL does not support UNCOMMITTED READ

Bottom line? : Unless an application requires a COMMITTED read (payment processing, auth, e-mail) , if it uses UNCOMMITTED reads, that’s better otherwise it may end up impacting DB performance and lead to blocking.