syntax for nolock in sql

Question

I have seen sql statements using nolock and with(nolock) e.g -

select * from table1 nolock where column1 > 10

AND

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Answer 1

Both are syntactically correct.

NOLOCK will become the alias for table1.

WITH (NOLOCK) is often exploited as a magic way to speed up database reads, but I try to avoid using it whever possible.

The result set can contain rows that have not yet been committed, that are often later rolled back.

An error or Result set can be empty, be missing rows or display the same row multiple times.

This is because other transactions are moving data at the same time you're reading it.

READ COMMITTED adds an additional issue where data is corrupted within a single column where multiple users change the same cell simultaneously.

There are other side-effects too, which result in sacrificing the speed increase you were hoping to gain in the first place.

Now you know, never use it again.