Question about extents in segment

Question

I got this alert from the database
Segment TST303 in tablespace TESTTBSPACE for database ORATSTDB unable to allocate next extent
When I checked with SQL
select OWNER, SEGMENT_NAME,EXTENTS,NEXT_EXTENT,INITIAL_EXTENT,MAX_EXTENTS from dba_segments where segment_name='TST303'OWNER SEGMENT_NAME EXTENTS NEXT_EXTENT INITIAL_EXTENT MAX_EXTENTS
TEST TST303 2 335544320 27156480 300
SQL> select tablespace_name,sum(bytes)/1024/1024 as Mb_Size from dba_free_space where tablespace_name='TESTTBSPACE' group by tablespace_name;
TABLESPACE_NAME MB_SIZE
TESTTBSPACE 1735.95313
It seems like cant extend next extent due to the size of the next extent is too big, but i dont really know how you calculate with them?

Answer 1

With the below code you can see next extent size for all your segments.. (tablespace_name not in ('SYSTEM', 'SYSAUX'))
select
segment_name,
tablespace_name,
case when next_extent is null then
(select max(e.bytes)
from dba_extents e
where e.segment_name = segment_name)
else next_extent end next_extent,
extents, ext_left,
case when max_extents = 2147483645
then 'Unlmtd'
else to_char(max_extents) end max_extents
from (select
s.segment_name,
s.tablespace_name,
s.next_extent,
s.extents,
s.max_extents,
sum(trunc(fs.bytes/s.next_extent)) ext_left,
(select count(*)
from sys.dba_free_space fs2
where s.tablespace_name = fs2.tablespace_name
and s.next_extent <= fs2.bytes) total
from
sys.dba_segments s, sys.dba_free_space fs
where
s.tablespace_name = fs.tablespace_name
and s.segment_type in
('TABLE','TABLE PARTITION','INDEX','INDEX PARTITION')
and s.tablespace_name not in ('SYSTEM', 'SYSAUX')
group by
s.segment_name, s.partition_name, s.tablespace_name,
s.next_extent, s.extents, s.max_extents);