dbms_space.free_space[8]

extremely useful  december 26, 2001
reviewer:  reader  from usa

tom,

thanks very much
i do plan on using lmt in new databases 

  december 27, 2001
reviewer:  dixit  from nj,usa

very good 

wow !  march 20, 2002
reviewer:  mini  from oh

exactly what i was looking for.

thank you so much tom 

how the extents are allocated in bytes  april 30, 2002
reviewer:  santosh jadhav  from india

it was a very good explanation tom.  but i have one doubt 

ops$tkyte@8i> select extent_id, bytes, blocks
  2    from user_extents
  3   where segment_name = 't'
  4     and segment_type = 'table'
  5  /

 extent_id      bytes     blocks
---------- ---------- ----------
         2      40960          5
         3      81920         10
         4      57344          7
         0      40960          5
         1      40960          5
                      ----------
sum                           32

this is what after creating table t with 40k initial and next extent.  so why it 
is 81920 (3rd extent) and 57344(4th extent). and why 7 and 10 blocks are 
allocated respectively
 

it is because i created the table in a dictionary managed tablespace and we 
allocate things to within +- 5 blocks (to avoid fragmenting the tablespace 
freespace totally)

read

it covers the algorithm. 

good stuff  september 16, 2002
reviewer:  doug  from ct, usa

system block is always 1 ?  january 09, 2003
reviewer:  tony  from india

does oracle allocate only one system block even for very big table?

 

at least one, it might get more later.  depends on block size and number of 
extents.