Simple Table space:It Can contain one or more tables Rows from multiple tables and can be interleaved on a page under the DBAs control and maintenance.

Segmented Tablespace:It Can contain one or more tables Tablespace is divided into segments of 4 to 64 pages in increments of 4 pages.Here Each segment is dedicated to single table.In Segmented tables the table can occupy multiple segments.

Partitioned Tablespace:It Can contain one table Tablespace is divided into parts and each part is put in a separate VSAM dataset.

The filter factor of a predicate is a number 0 - 1. The number estimates the proportion of rows in a table for which the predicate is true. Those rows are said to qualify by that predicate.

Synonym is an alternate name for a table or view and its used mainly to hide the leading Qualifier of a table or view. And the synonym is accessible only by the creator.

SYNONYM:
SYNONYM is dropped when the table or table space is dropped and it is available only to the creator.
ALIAS:
ALIAS is retained even if the table or table space is dropped and it can be created even if the table does not exist. ALIAS is used mainly in distributed environment to hide the location info from programs, and it is a global object and it is available to all.

This column cannot have nulls and while insertion, if no value is supplied then it wil have zeroes, spaces or date/time depending on whether it is numeric, character or date/time Use it when you do not want to have nulls but at the same time cannot give values all the time you insert this row.