DATABASE_PROPERTIES and Bigfile Tablespaces
The data dictionary view DATABASE_PROPERTIES, as the name implies, contains a number of
characteristics about the database, such as the names of the default and permanent tablespaces
and various NLS settings. Because of bigfile tablespaces, there is a new property in DATABASE_
PROPERTIES called DEFAULT_TBS_TYPE that indicates the default tablespace type for the
database if no type is specified in a create tablespace command. In the following example,
you can find out the default new tablespace type:
SQL> select property_name, property_value, description
2 from database_properties
3 where property_name = 'DEFAULT_TBS_TYPE';
PROPERTY_NAME PROPERTY_VALUE DESCRIPTION
------------------ ---------------- ------------------------
DEFAULT_TBS_TYPE BIGFILE Default tablespace type
1 row selected.
*_TABLESPACES, V$TABLESPACE, and Bigfile Tablespaces
The data dictionary views DBA_TABLESPACES and USER_TABLESPACES have a new column
called BIGFILE. The value of this column is YES if the corresponding tablespace is a bigfile
tablespace, as you saw in the query against DBA_TABLESPACES earlier in this chapter. The
dynamic performance view V$TABLESPACE also contains this column.
Advanced Oracle Table Types
Many other table types provide benefits in a VLDB environment. Index-organized tables, for
example, eliminate the need for both a table and its corresponding index, replacing them with
a single structure that looks like an index but contains data like a table.
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