Very high data block waits

Question

I have one table xxxx in a tablespace tbx and the tablespace tbx has only 1 datafile. The table xxxx size is 890MB w/ 14 millions records. The datafile size is 2048MB. This table is a frequently access with insert/delete/select. The system spends alot of time waiting on this datafile. If I create a new tablespace abc with 20 datafiles worth about 100MB each, would it help reducing the data block wait count? The pctfree/pctused is 10/40 respectively.
Can anyone please give me an how to resolve this?

Answer 1

I am looking at an Oracle Statistics. We use SAN technology with RAID 0+1 Striped across all disks.
First I use this query to get the wait statistics:
select time, count, class
from v$waitstat
order by time, count;
From this query above, I got this result and database just been up 02/17/2004, just about 4 days ago:
TIME COUNT CLASS
0 0 sort block
0 0 save undo block
0 0 save undo header
0 0 free list
0 0 bitmap block
0 0 unused
0 0 system undo block
0 0 system undo header
0 0 bitmap index block
10 10 extent map
48 656 undo header
271 853 undo block
301 730 segment header
780382 1214405 data block
Then I use this query to find which datafile is being hit the most:
select count, file#, name
from x$kcbfwait, v$datafile
where indx + 1 = file#
order by count desc;
The query above returned:
COUNT     FILE#     NAME
473324     121     /xx/xx_ycm_tbs_03_01.dbf
104179     120     /xx/xx_ycm_tbs_02_01.dbf
93336     118     /xx/xx_idx_tbs_03_01.dbf
93138     119     /xx/xx_idx_tbs_03_02.dbf
80289     90     /xx/xx_datafile67.dbf
64044     108     /xx/xx_ycm_tbs_01_01.dbf
61485     41     /xx/xx_datafile25.dbf
61103     21     /xx/xx_datafile8.dbf
57329     114     /xx/xx_ycm_tbs_01_02.dbf
29338     5     /xx/xx_datafile02.dbf
29101     123     /xx/xx_idx_tbs_04_01.dbf
file# 121 is in a tablespace with this only datafile and this tablespace hold only one table. file#120 is the same thing, it's in another tablespace and only one table in that tablespace.
At the same time, i use TOP in Solaris I see iowait range between 5-25% during busy hour.