It's all about the unreasonable design of clob with big fields.

Source: Internet
Author: User

The session has been changed.
Used time: 00: 00: 00.01
SQL> select * from cfms_questions;
Row 4587 has been selected.

Execution Plan
----------------------------------------------------------
Plan hash value: 3912515109
Bytes ------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (% CPU) | Time |
Bytes ------------------------------------------------------------------------------------
| 0 | select statement | 3804 | 1329K | 68 (0) | 00:00:01 |
| 1 | table access full | CFMS_QUESTIONS | 3804 | 1329K | 68 (0) | 00:00:01 |
Bytes ------------------------------------------------------------------------------------
Statistics
----------------------------------------------------------
1 recursive cballs
1 db block gets
4637 consistent gets
4 physical reads
0 redo size
4300934 bytes sent via SQL * Net to client
2387052 bytes encoded ed via SQL * Net from client
13798 SQL * Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
4587 rows processed
SQL> alter session set events '10046 trace name context off ';

From
Cfms_questions
Call count cpu elapsed disk query current rows
-----------------------------------------------------------------------
Parse 1 0.00 0.01 0 0 0 0
Execute 1 0.00 0.00 0 0 0 0
Fetch 4588 0.28 0.37 0 4633 1 4587
-----------------------------------------------------------------------
Total 4590 0.28 0.38 0 4633 1 4587
Misses in library cache during parse: 1
Optimizer mode: ALL_ROWS
Parsing user id: 96
Rows Row Source Operation
----------------------------------------------------------
4587 table access full CFMS_QUESTIONS (cr = 4633 pr = 0 pw = 0 time = 111289 us cost = 68 size = 1361832 card = 3804)
Elapsed times include waiting on following events:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ----------------------
SQL * Net message to client 4589 0.00 0.02
SQL * Net message from client 4589 0.00 3.18
SQL * Net more data to client 11 0.00 0.00
SQL * Net more data from client 8 0.00 0.00
**************************************** ****************************************

Select * from cfms_questions
END OF STMT
PARSE #707451568: c = 0, e = 10817, p = 0, cr = 0, cu = 0, mis = 1, r = 0, dep = 0, og = 1, plh = 3912515109, tim = 53142591819
EXEC #707451568: c = 0, e = 61, p = 0, cr = 0, cu = 0, mis = 0, r = 0, dep = 0, og = 1, plh = 3912515109, tim = 53142592040
........................................ ......................


WAIT #0: nam = 'SQL * Net message from client' ela = 656 driver id = 1413697536 # bytes = 1 p3 = 0 obj # = 132667 tim = 53142594989
WAIT #0: nam = 'SQL * Net message to client' ela = 4 driver id = 1413697536 # bytes = 1 p3 = 0 obj # = 132667 tim = 53142595099
LOBREAD: c = 0, e = 68, p = 0, cr = 0, cu = 0, tim = 53142595131


2 VERSION_ID,
3 MODULE_ID,
4 STATE,
5 CATA,
6 CREATOR_ID,
7 DISCOVER_TIME,
8 PS_ONLINE_VERSION,
9 PS_SOLVE_TIME,
10 CREATOR,
11 RESULT,
12 CONTACT_WAY,
13 RESOLVE_TIME,
14 DEPARTMENT_ID,
15 SERVICE_ID,
16 SYSTEM_ID
17 from CFMS_QUESTIONS;
Row 4587 has been selected.

Execution Plan
----------------------------------------------------------
Plan hash value: 3912515109
Bytes -----------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (% CPU) | Time |
Bytes ------------------------------------------------------------------------------------
| 0 | select statement | 3804 | 631K | 68 (0) | 00:00:01 |
| 1 | table access full | CFMS_QUESTIONS | 3804 | 631K | 68 (0) | 00:00:01 |
Bytes ------------------------------------------------------------------------------------
Statistics
----------------------------------------------------------
0 recursive cballs
1 db block gets
550 consistent gets
0 physical reads
0 redo size
168413 bytes sent via SQL * Net to client
3693 bytes encoded ed via SQL * Net from client
307 SQL * Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
4587 rows processed


SQL> select ID,
2 VERSION_ID,
3 MODULE_ID,
4 STATE,
5 CATA,
6 CREATOR_ID,
7 DISCOVER_TIME,
8 PS_ONLINE_VERSION,
9 PS_SOLVE_TIME,

11 CREATOR,
12 RESULT,
13 CONTACT_WAY,
14 RESOLVE_TIME,
15 DEPARTMENT_ID,
16 SERVICE_ID,
17 SYSTEM_ID
18 from CFMS_QUESTIONS;
Row 4587 has been selected.

Execution Plan
----------------------------------------------------------
Plan hash value: 3912515109
Bytes ------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (% CPU) | Time |
Bytes ------------------------------------------------------------------------------------
| 0 | select statement | 3804 | 1329K | 68 (0) | 00:00:01 |
| 1 | table access full | CFMS_QUESTIONS | 3804 | 1329K | 68 (0) | 00:00:01 |
Bytes ------------------------------------------------------------------------------------
Statistics
----------------------------------------------------------
1 recursive cballs
1 db block gets
4637 consistent gets
4 physical reads
0 redo size
4300934 bytes sent via SQL * Net to client
2387052 bytes encoded ed via SQL * Net from client
13798 SQL * Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
4587 rows processed

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