CTAS method takes long time - Any suggestion.

Question

Hi,
Please find the query below. The 'select' statement was taking more than a day time to execute and i tuned the same. Now i am getting the results in 5 seconds. But when i try to load the data that i get from 'select' statement into table using CTAS method, it takes more than 5 hours, but i don't see table created. Little background about this query...., this is for data warehousing project, every table in the 'select' has 5million records. The result set (executes in 5 second) will again have 5 million records. When loading the data into table for 5m records, it takes time. Is there a way to improve this.
create table tcu
tablespace tcu_cons
as
select /*+ ORDERED INDEX(a) INDEX(b) INDEX(c) INDEX(d) INDEX(e) INDEX(f) INDEX(g) USE_NL(a,b) USE_NL(b,c) USE_NL(c,d) USE_NL(d,e) USE_NL(e,f) USE_NL(f,g) */
a.prev_mo_tbr_amt,
(b.ytd_tbr_amt + NVL(g.tot_cris_tbr_amt,0)) ytd_tbr_amt,
c.prev_ytd_tbr_amt,
(d.lst_12_mo_tbr_amt + NVL(g.tot_cris_tbr_amt,0)) lst_12_mo_tbr_amt,
e.prev_lst_12_mo_tbr_amt,
f.sm_mo_lst_yr_tbr_amt,
g.tot_cris_tbr_amt,
a.row_id
from tmp_prevmo a,
tmp_ytd b,
tmp_prevytd c,
tmp_lst12 d,
tmp_prevlst12 e,
tmp_smmolstyr f,
csban_1 g
where a.acct_id = b.acct_id
and b.acct_id = c.acct_id
and c.acct_id = d.acct_id
and d.acct_id = e.acct_id
and e.acct_id = f.acct_id
and f.acct_id = g.acct_id;
Thanks,
Subbu.

Answer 1

Hi Alex,
I am talking about the first rows that returned with in 5 seconds.
I have already taken my explain plan and read it. It seems to be fine including cost.
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
| 0 | SELECT STATEMENT | | 5116K| 356M| 107M (1)|419:26:06 |
| 1 | TABLE ACCESS BY INDEX ROWID | CSBAN_1 | 1 | 10 | 4 (0)| 00:00:01 |
| 2 | NESTED LOOPS | | 5116K| 356M| 107M (1)|419:26:06 |
| 3 | NESTED LOOPS | | 5116K| 307M| 87M (1)|339:30:36 |
| 4 | NESTED LOOPS | | 5116K| 263M| 71M (1)|279:29:30 |
| 5 | NESTED LOOPS | | 5120K| 219M| 51M (1)|199:26:29 |
| 6 | NESTED LOOPS | | 5120K| 175M| 35M (1)|139:22:34 |
| 7 | NESTED LOOPS | | 5120K| 136M| 20M (1)| 79:18:39 |
| 8 | TABLE ACCESS BY INDEX ROWID| TMP_PREVMO | 5125K| 102M| 4901K (1)| 19:03:36 |
| 9 | INDEX FULL SCAN | TMP_PREVMO_PK | 5125K| | 7590 (8)| 00:01:47 |
| 10 | TABLE ACCESS BY INDEX ROWID| TMP_YTD | 1 | 7 | 4 (0)| 00:00:01 |
|* 11 | INDEX RANGE SCAN | TMP_YTD_PK | 1 | | 2 (0)| 00:00:01 |
| 12 | TABLE ACCESS BY INDEX ROWID | TMP_PREVYTD | 1 | 8 | 3 (0)| 00:00:01
|* 13 | INDEX RANGE SCAN | TMP_PREVYTD_PK | 1 | | 2 (0)| 00:00:01 |
| 14 | TABLE ACCESS BY INDEX ROWID | TMP_LST12 | 1 | 9 | 3 (0)| 00:00:01 |
|* 15 | INDEX RANGE SCAN | TMP_LST12_PK | 1 | | 2 (0)| 00:00:01 |
| 16 | TABLE ACCESS BY INDEX ROWID | TMP_PREVLST12 | 1 | 9 | 4 (0)| 00:00:01
|* 17 | INDEX RANGE SCAN | TMP_PREVLST12_PK | 1 | | 2 (0)| 00:00:01 |
| 18 | TABLE ACCESS BY INDEX ROWID | TMP_SMMOLSTYR | 1 | 9 | 3 (0)| 00:00:01
|* 19 | INDEX RANGE SCAN | TMP_SMMOLSTYR_PK | 1 | | 2 (0)| 00:00:01 |
|* 20 | INDEX RANGE SCAN | CSBAN_1_PK | 1 | | 2 (0)| 00:00:01 |
Predicate Information (identified by operation id):
11 - access("A"."ACCT_ID"="B"."ACCT_ID")
13 - access("B"."ACCT_ID"="C"."ACCT_ID")
15 - access("C"."ACCT_ID"="D"."ACCT_ID")
17 - access("D"."ACCT_ID"="E"."ACCT_ID")
19 - access("E"."ACCT_ID"="F"."ACCT_ID")
20 - access("F"."ACCT_ID"="G"."ACCT_ID")
Thanks,
Subbu.