Partition

What is partition? How many types of partition.

Spliting a table or index into smaller & more manageable pieces is called partitions.
Each partition of a table or index must have the same logical attributes,
such as column names, datatypes, and constraints.

There are several partitioning methods viz:
a. List Partition
b. Range Partition
c. Hash Partition
d. Composite Partition

Statistics

What is Statistics.
Statistics is a mechanism which gives the information about size of table, data of table, column of table and other information of table. These stastistics are used by the CBO(Cost Based Optimizer) to generate the best execution plan for each SQL statement.

Optimizer Statistics are a collection of data that describe more details about the database and the objects in the database. These statistics are used by the query optimizer to choose the best execution plan for each SQL statement.