hemant sharma

• Oct 1st, 2007

 

The basic diff between a locally managed tablespace and a dictionary managed tablespace is that in the dictionary managed tablespace every time a extent is allocated or deallocated data dictionary is updated which increases the load on data dictionary, while in case of locally managed tablespace the space information is kept inside the datafile in the form of bitmaps every time a extent is allocated or deallocated only the bitmap is updated which removes burden from data dictionary.

sanjay garg

 Profile Answers by sanjay garg 

• Mar 18th, 2009

 

When Oracle allocates space to a segment (like a table or index), a group of contiguous free blocks, called an extent, is added to the segment. Metadata regarding extent allocation and unallocated extents are either stored in the data dictionary, or in the tablespace itself. Tablespaces that record extent allocation in the dictionary, are called dictionary managed tablespaces, and tablespaces that record extent allocation in the tablespace header, are called locally managed tablespaces.

Surya

• Jun 15th, 2017

 

When Oracle allocates space to a segment (like a table or index), a group of contiguous free blocks, called an extent, is added to the segment. Metadata regarding extent allocation and unallocated extents are either stored in the data dictionary, or in the tablespace itself

jayesh gaikar

• Nov 6th, 2018

 

LMT(Locally Managed Tablespace) :In LMT Extents are managed at the data file level.
DMT(Dictionary Managed Tabalespace) :Extent management in DMT is maintained and carried out at the data dictionary level.