How to get size of all tables in an Oracle database schema

If you ever wanted to know how what’s taking space in an Oracle database, or how large is the table you’re working on, here’s a script which answers these questions. It shows the size of all the database objects large than 10 Mb in a particular database schema.

The following columns are returned:

  • Owner schema.
  • Object name and type (INDEX, TABLE, etc.).
  • Name of the table this object is associated with. E.g. indexes are associated with their parent tables.
  • Database space occupied by the object in megabytes.
  • Tablespace this object is in.
  • Number of extents allocated for the object.
  • Size of the initial extent in bytes.
  • Total database size occupied by the parent table. E.g. for indexes it will be the size of the parent * table plus sizes of all the indexes on that table.

This script is based on the discussion.