1)what is the difference between view and materilized view? 2)what is the diffe

1)what is the difference between view and materilized view?
2)what is the difference between delete and truncate?
3)what is the difference between migration and upgration?
4)what is the difference between RMAN HOT BACKUP and normal
hot backup?

Question Posted / nijamudeen83@gmail.com

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1)what is the difference between view and materilized view? 2)what is the difference between delete..

Answer / praveen hattikal

2)Truncate is a DDL command, which has autocommit hence
cant be rolled back where as delete is DML with user commit
& roll back option. Truncate is faster then delete since it
wont store any data to backup tablespace. before delting.

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1)what is the difference between view and materilized view? 2)what is the difference between delete..

Answer / praveen hattikal

1)views , Materialized view or summary tables are subset of
a table filtering out uninteresting rows and columns.The
difference is that views are logical where as MV's are
actual tables.Views pulls real time data when ever queried
but data in MV is rfereshed based on users need.also when
you query a materialized view, you are querying a table,
which may also be indexed. In addition, because all the
joins have been resolved at materialized view refresh time,
you pay the price of the join once (or as often as you
refresh your materialized view), rather than each time you
select from the materialized view .Materialized views are
most often used in data warehousing / business intelligence
applications where querying large fact tables with
thousands of millions of rows would result in query
response times that resulted in an unusable.

2)