ORACLE TABLE INFORMATION

Depending on column to find out table

select * from cols

Depending on constrain to find out table

select * from dba_constraints 

select * from dba_cons_columns

Find out record number of table

select table_name, num_rows from dba_tables

Depending on name, find out type

select object_name, object_type from dba_objects

Depending on name, find out size

select segment_name, bytes / 1024 / 1024 ||'M' from dba_segments