Sunday, January 16, 2011

What are the scenarios in which Full Table Scans occurs?

What are the scenarios in which Full Table Scans occurs?

1. The where clause in SELECT statement does not use either primary index or secondary index
2. SQL Statement which uses a partial value (like or not like), in the WHERE statement.
3. SQL Statement which does not contain where clause.
4. SQL statement using range in where clause. Ex. (col1 > 40 or col1 < =10000)

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