SCRIPT TO CALCUTE POSSIBLE RESIZE VALUE


Sometimes, we will be getting a requirement to resize the datafile to a lower value in order to create some space in the mount point (file system). In that case, how we would know which datafile and to what size we can lower it? The below script will helps us in that….



set verify off
column file_name format a50 word_wrapped
column smallest format 999,990 heading “Smallest|Size|Poss.”
column currsize format 999,990 heading “Current|Size”
column savings format 999,990 heading “Poss.|Savings”
break on report
compute sum of savings on report

column value new_val blksize
select value from v$parameter where name = ‘db_block_size’
/

select file_name,
ceil( (nvl(hwm,1)*&&blksize)/1024/1024 ) smallest,
ceil( blocks*&&blksize/1024/1024) currsize,
ceil( blocks*&&blksize/1024/1024) -
ceil( (nvl(hwm,1)*&&blksize)/1024/1024 ) savings
from dba_data_files a,
( select file_id, max(block_id+blocks-1) hwm
from dba_extents
group by file_id ) b
where a.file_id = b.file_id(+)
/

select file_name,
ceil( (nvl(hwm,1)*&&blksize)/1024/1024 ) smallest,
ceil( blocks*&&blksize/1024/1024) currsize,
ceil( blocks*&&blksize/1024/1024) -
ceil( (nvl(hwm,1)*&&blksize)/1024/1024 ) savings
from dba_temp_files a,
( select file_id, max(block_id+blocks-1) hwm
from dba_extents
group by file_id ) b
where a.file_id = b.file_id(+)
/

column cmd format a75 word_wrapped

select ‘alter database datafile ”’ || file_name || ”’ resize ‘ ||
ceil( (nvl(hwm,1)*&&blksize)/1024/1024 ) || ‘m;’ cmd
from dba_data_files a,
( select file_id, max(block_id+blocks-1) hwm
from dba_extents
group by file_id ) b
where a.file_id = b.file_id(+)
and ceil( blocks*&&blksize/1024/1024) -
ceil( (nvl(hwm,1)*&&blksize)/1024/1024 ) > 0
/


select ‘alter database tempfile ”’ || file_name || ”’ resize ‘ ||
ceil( (nvl(hwm,1)*&&blksize)/1024/1024 ) || ‘m;’ cmd
from dba_temp_files a,
( select file_id, max(block_id+blocks-1) hwm
from dba_extents
group by file_id ) b
where a.file_id = b.file_id(+)
and ceil( blocks*&&blksize/1024/1024) -
ceil( (nvl(hwm,1)*&&blksize)/1024/1024 ) > 0