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Len() and DataLength()

May 162013

Both system functions, Len() and DataLength(), in SQL Server are used to measure the length of the data. The main difference of those 2 is that Len() gets the string length of the data in which DataLength measures the storage length of the data.
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Truncate

Storage, T-SQL

Dec 232011

What are the differences between TRUNCATE and DELETE? You may immediately point out that:

Truncates reset the identity value
Truncates can’t have where clause
Truncates can’t be run on a table which is referenced by other tables
Truncates do not fire triggers.
Truncates can’t be run on a table which has depending objects such as indexed views.
Truncates can’t be run on a table which has published by merge or transactional replication publication
Truncates need db_owner and db_ddladmin permission.
Truncates need locks on the table and schema but do not need locks on rows of the tables

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