Which one is faster delete/truncate? Why?
Assuming you are talking about deleting the whole population of a table it doesn't matter if it's Oracle, SQL Server, DB2 or whatever other RDBMS truncate will always be faster.
In the particular case of Oracle, truncate is not a DML but a pure DDL operation that resets the High Watermark of the table. Truncate statements in Oracle do not generate redo logs therefore, this is an instantaneous process - in SQL Server, truncate statements are minimally logged.
Pablo (Paul) Berzukov
Author of Understanding Database Administration
available at Amazon and other bookstores.Disclaimer: Advice is provided to the best of my knowledge but no implicit or explicit warranties are provided. Since the advisor explicitly encourages testing any and all suggestions on a test non-production environment advisor should not held liable or responsible for any actions taken based on the given advice.