Dependent LU Requester. The client half of the Dependent LU Requestor/Server enhancement to APPN. The DLUR component resides in APPN ENs and NNs that support adjacent DLUs by securing services from the DLUS.

control point. In SNA networks, element that identifies the APPN networking components of a PU 2.1 node, manages device resources, and can provide services to other devices. In APPN, CPs are able to communicate with logically adjacent CPs by way of CP-to-CP sessions

boundary network node. In SNA terminology, a subarea node that provides boundary function support for adjacent peripheral nodes. This support includes sequencing, pacing, and address translation. Also called boundary node.

A free extent in a dictionary-managed tablespace is made up of a collection of contiguous free blocks. When allocating new extents to a tablespace segment, the database uses the free
extent closest in size to the required extent. In some cases, when segments are
dropped, their extents are deallocated and marked as free, but adjacent free
extents are not immediately recombined into larger free extents. The result is
fragmentation that makes allocation of larger extents more difficult.


Oracle Database addresses fragmentation in several ways: When attempting to allocate a new extent for a segment, the database first tries
to find a free extent large enough for the new extent. Whenever the database cannot
find a free extent that is large enough for the new extent, it coalesces adjacent
free extents in the tablespace and looks again.





The SMON background process periodically coalesces neighboring free extents when
the PCTINCREASE value for a tablespace is not zero. If you set PCTINCREASE=0, no coalescing of free extents occurs.If you are concerned
about the overhead of ongoing coalesce operations of SMON, an alternative is to set
PCTINCREASE=0, and periodically coalesce free space manually. Manually Coalesce any adjacent free extens user this command:
ALTER TABLESPACE <<TABLESPACENAME>> COALESCE 

-> Temporary tablespace is locally managed tablespace  AND Permanent tablespace is dictionary managed tablespace
-> When an extent is allocated or freed for reuse changes occurs in tables.In case of Temporary tablespace changes happen in bitmaps but in Permanent tablespace System Tables gets updated.
-> Temporary Tablespace automatically tracks adjacent free space.