The query makes a full table scan?

I have a simple select query that filters on the last 10 or 11 days of data in a table. In the first case, it runs in 1 second. In the second case it takes 15 minutes and still not done.

I can say that the second query (11 days) makes a full table scan.
-Why is this happening? ... I guess some kind of threshold?
-Are there a way to avoid this? ... or encourage Oracle to play nice.

I find confusing from the point of view before end/query to get very different performances.

Jason
Oracle 10g
Toad quest 10.6

CREATE TABLE delme10 AS 
SELECT *
FROM ed_visits
WHERE first_contact_dt >= TRUNC(SYSDATE-10,'D');

Plan hash value: 915912709

--------------------------------------------------------------------------------------------------
| Id  | Operation                    | Name              | Rows  | Bytes | Cost (%CPU)| Time     |
--------------------------------------------------------------------------------------------------
|   0 | CREATE TABLE STATEMENT       |                   |  4799 |  5534K|  4951   (1)| 00:01:00 |
|   1 |  LOAD AS SELECT              | DELME10           |       |       |            |          |
|   2 |   TABLE ACCESS BY INDEX ROWID| ED_VISITS         |  4799 |  5534K|  4796   (1)| 00:00:58 |
|*  3 |    INDEX RANGE SCAN          | NDX_ED_VISITS_020 |  4799 |       |    15   (0)| 00:00:01 |
--------------------------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   3 - access("FIRST_CONTACT_DT">=TRUNC(SYSDATE@!-10,'fmd'))


CREATE TABLE delme11 AS 
SELECT *
FROM ed_visits
WHERE first_contact_dt >= TRUNC(SYSDATE-11,'D');
Plan hash value: 1113251513

-----------------------------------------------------------------------------------------------------------------
| Id  | Operation              | Name      | Rows  | Bytes | Cost (%CPU)| Time     |    TQ  |IN-OUT| PQ Distrib |
-----------------------------------------------------------------------------------------------------------------
|   0 | CREATE TABLE STATEMENT |           | 25157 |    28M| 14580   (1)| 00:02:55 |        |      |            |
|   1 |  LOAD AS SELECT        | DELME11   |       |       |            |          |        |      |            |
|   2 |   PX COORDINATOR       |           |       |       |            |          |        |      |            |
|   3 |    PX SEND QC (RANDOM) | :TQ10000  | 25157 |    28M| 14530   (1)| 00:02:55 |  Q1,00 | P->S | QC (RAND)  |
|   4 |     PX BLOCK ITERATOR  |           | 25157 |    28M| 14530   (1)| 00:02:55 |  Q1,00 | PCWC |            |
|*  5 |      TABLE ACCESS FULL | ED_VISITS | 25157 |    28M| 14530   (1)| 00:02:55 |  Q1,00 | PCWP |            |
-----------------------------------------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   5 - filter("FIRST_CONTACT_DT">=TRUNC(SYSDATE@!-11,'fmd'))

This seems to change the plan to explain it...

alter session set optimizer_index_cost_adj=10;

Tags: Database

Similar Questions

Tuning sql insert that inserts 1 million lines makes a full table scan

Hi Experts,
I'm on Oracle 11.2.0.3 on Linux. I have a sql that inserts data into a table of History/Archives of a table main application based on the date. The application table has 3 million lines. and all the lines that are more then 6 months old must go in a table of History/Archives. This was decided recently, and we have 1 million rows that meet this criterion. This insertion in table archive takes about 3 minutes. Plan of the explain command shows a full table scan on the main Board - which is the right thing, because we are pulling 1 million rows in the main table in the history table.
My question is that, is it possible that I can do this sql go faster?
Here's the query plan (I changed the names of table etc.)
```
   INSERT INTO EMP_ARCH
   SELECT *
FROM EMP M
where HIRE_date < (sysdate - :v_num_days);
call     count       cpu    elapsed       disk      query    current        rows
------- ------  -------- ---------- ---------- ---------- ----------  ----------
Parse        2      0.00       0.00          0          0          0           0
Execute      2     96.22     165.59      92266     147180    8529323     1441230
Fetch        0      0.00       0.00          0          0          0           0
------- ------  -------- ---------- ---------- ---------- ----------  ----------
total        4     96.22     165.59      92266     147180    8529323     1441230
Misses in library cache during parse: 1
Misses in library cache during execute: 1
Optimizer mode: FIRST_ROWS
Parsing user id: 166
Rows     Row Source Operation
-------  ---------------------------------------------------
1441401   TABLE ACCESS FULL EMP (cr=52900 pr=52885 pw=0 time=21189581 us)
```
I heard that there is a way to use opt_param tip to increase the multiblock read County but did not work for me... I will be grateful for suggestions on this. can collections and this changing in pl/sql also make it faster?
Thank you
OrauserN

(1) create an index on hire_date

(2) tip 'additional' use in the 'select' query '

(3) run ' alter session parallel DML'; before you run the entire statement

FULL TABLE SCAN even with the index, but why?
Could someone please explain why I'd get FULL TABLE SCAN explain plan results when joining 2 tables on columns that already have clues about them? For example,.
consider this fictional scenario:

employee table with columns:
employee # (primary key column)
name

address table with columns:
employee # (foreign key to employee.employee #)
subscription_type
address

Select Employee.Name since it is, address.address_type, address.address
where employee.employee # = address.employee #.

This query shows a full table scan in terms of the explain command.
Full scan of the table is not necessarily slow and index access is not necessarily fast.

You will recover, no doubt, most if not all the ranks on both sides. The fastest way to retrieve each row in a table is to do a table scan. Using an index, and a single block of reading for each row in a table is much less effective than to do a table scan.

Justin

Path to XML index table is full table scan

Hi all
I have a version of oracle 11.2.0.4.6 database
Try to implement partitioning on XML indexes.
Creates a table and index partitioned by time stamp as below.
Whenever I'm trying to find the path table makes a full table scan.
I have applied the fix as indicated ( Doc ID 13522189.8 ).
So the recovery is quite slow and partition pruning does not not on XML indexes.
Wondering if anyone has experienced the same problem?
CREATE TABLE INCIDENT
(
INCIDENT_PK NUMBER (14.5).
INCIDENTGROUPING_PK NUMBER (14.5).
INCIDENTTYPE_PK NUMBER (14.5).
SECURITYCLASS_PK NUMBER (14.5).
STAMP OF INCIDENT_DATE,
SYS INCIDENT_DETAIL. XMLTYPE
)
TABLESPACE DATA_TBS_INCIDENT
PCTUSED 0
PCTFREE 10
INITRANS 1
MAXTRANS 255
STORAGE)
64K INITIALS
MINEXTENTS 1
MAXEXTENTS UNLIMITED
PCTINCREASE 0
DEFAULT USER_TABLES
)
LOGGING
NOCOMPRESS
PARTITION BY RANGE (INCIDENT_DATE)
(PARTITION SEP2013_WEEK1 VALUES LESS THAN (to_timestamp (' 00:00:00.00 2013-09-08 ',' YYYY-MM-DD HH24:MI:SS.))) FF2')),
PARTITION SEP2013_WEEK2 VALUES LESS THAN (to_timestamp ('2013-09-15 00:00:00.00 ',' YYYY-MM-DD HH24:MI:SS.)) FF2')),
PARTITION SEP2013_WEEK3 VALUES LESS THAN (to_timestamp ('2013-09-22 00:00:00.00 ',' YYYY-MM-DD HH24:MI:SS.)) FF2')),
..........);
CREATE the INDEX INCIDENTxdb_idx
ON corpaudlive. INCIDENT (INCIDENT_detail) INDEXTYPE IS XDB. LOCAL XMLINDEX 10 PARALLEL
PARAMETERS (' PATH TABLE INCIDENT_PATHTABLE (TABLESPACE DATA_TBS_INCIDENT))
PIKEY INDEX INCIDENT_PATHTABLE_PIKEY_IX (TABLESPACE IDX_TBS_INCIDENT)
PATH ID INDEX INCIDENT_PATHTABLE_ID_IX (TABLESPACE IDX_TBS_INCIDENT)
INCIDENT_PATHTABLE_VALUE_IX VALUE INDEX (TABLESPACE IDX_TBS_INCIDENT)
ORDER KEY INDEX INCIDENT_PATHTABLE_KEY_IX (TABLESPACE IDX_TBS_INCIDENT)
Paths (INCLUDE (//forename //surname //postcode //dateofbirth //street //town))');
SQL > explain the plan for
2 Select INCIDENT_pk in INCIDENT where XMLEXISTS ('/ / name [text () = 'john']' by the way of INCIDENT_detail)
3 and XMLEXISTS ("/ / name [text () 'clark' =]' by the way of INCIDENT_detail")
4 and a.INCIDENT_date between TO_TIMESTAMP (January 10, 2014 ',' DD/MM/YYYY "")
5 and TO_TIMESTAMP (September 10, 2014 ',' DD/MM/YYYY ');
He explained.
Elapsed time: 00:00:02.77
SQL > select * from table (dbms_xplan.display);
PLAN_TABLE_OUTPUT
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Hash value of plan: 123057549
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| ID | Operation                                       | Name                           | Lines | Bytes | Cost (% CPU). Time | Pstart. Pstop |    TQ | IN-OUT | PQ Distrib.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT |                                |     1.    70. 1803 (5) | 00:00:22 |       |       |        |      |            |
|   1. COORDINATOR OF PX |                                |       |       |            |          |       |       |        |      |            |
|   2.   PX SEND QC (RANDOM). : TQ10003 |     1.    70. 1803 (5) | 00:00:22 |       |       | Q1, 03 | P > S | QC (RAND) |
|   3.    SEMI NESTED LOOPS.                                |     1.    70. 1803 (5) | 00:00:22 |       |       | Q1, 03 | SVCP |            |
|   4.     NESTED LOOPS |                                |     1.    57. 1800 (5) | 00:00:22 |       |       | Q1, 03 | SVCP |            |
|   5.      VIEW                                       | VW_SQ_1                        |   239. 5975 | 1773 (5) | 00:00:22 |       |       | Q1, 03 | SVCP |            |
PLAN_TABLE_OUTPUT
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|   6.       UNIQUE HASH |                                |   239. 25334 |            |          |       |       | Q1, 03 | SVCP |            |
|   7.        RECEIVE PX |                                |   239. 25334 |            |          |       |       | Q1, 03 | SVCP |            |
|   8.         PX SEND HASH | : TQ10002 |   239. 25334 |            |          |       |       | Q1, 02 | P > P | HASH |
|   9.          UNIQUE HASH |                                |   239. 25334 |            |          |       |       | Q1, 02 | SVCP |            |
| * 10 |           HASH JOIN |                                |   239. 25334 | 1773 (5) | 00:00:22 |       |       | Q1, 02 | SVCP |            |
| 11.            KIND OF BUFFER.                                |       |       |            |          |       |       | Q1, 02 | ISSUE |            |
| 12.             RECEIVE PX |                                |     1.    22.     3 (0) | 00:00:01 |       |       | Q1, 02 | SVCP |            |
| 13.              PX SEND BROADCAST | : TQ10000 |     1.    22.     3 (0) | 00:00:01 |       |       |        | S > P | BROADCAST |
| 14.               TABLE ACCESS BY INDEX ROWID | X$ PT74MSS0WBH028JE0GUCLBK0LHM4 |     1.    22.     3 (0) | 00:00:01 |       |       |        |      |            |
| * 15 |                INDEX RANGE SCAN | X$ PR74MSS0WBH028JE0GUCLBK0LHM4 |     1.       |     2 (0) | 00:00:01 |       |       |        |      |            |
| * 16.            HASH JOIN |                                | 12077 |   990K | 1770 (5) | 00:00:22 |       |       | Q1, 02 | SVCP |            |
PLAN_TABLE_OUTPUT
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| 17.             RECEIVE PX |                                |   250K |    10 M |    39 (0) | 00:00:01 |       |       | Q1, 02 | SVCP |            |
| 18.              PX SEND BROADCAST | : TQ10001 |   250K |    10 M |    39 (0) | 00:00:01 |       |       | Q1, 01 | P > P | BROADCAST |
| 19.               SYSTEM PARTITION ALL |                                |   250K |    10 M |    39 (0) | 00:00:01 |     1.   112. Q1, 01 | ISSUE |            |
| * 20.                TABLE ACCESS BY LOCAL INDEX ROWID | INCIDENT_PATHTABLE |   250K |    10 M |    39 (0) | 00:00:01 |     1.   112. Q1, 01 | SVCP |            |
| * 21.                 INDEX RANGE SCAN | INCIDENT_PATHTABLE_VALUE_IX |   161.       |    25 (0) | 00:00:01 |     1.   112. Q1, 01 | SVCP |            |
| 22.             ITERATOR BLOCK PX |                                |   221 M | 8865M | 1671 (1) | 00:00:21 |    53.    54. Q1, 02 | ISSUE |            |
| * 23.              TABLE ACCESS FULL | INCIDENT_PATHTABLE |   221 M | 8865M | 1671 (1) | 00:00:21 |    53.    54. Q1, 02 | SVCP |            |
| * 24.      TABLE ACCESS BY ROWID USER | INCIDENT |     1.    32.     1 (0) | 00:00:01 | ROWID | ROWID | Q1, 03 | SVCP |            |
| * 25.     SEE PUSHED PREDICATE. VW_SQ_2                        |     1.    13.    20 (0) | 00:00:01 |       |       | Q1, 03 | SVCP |            |
| 26.      NESTED LOOPS |                                |     1.   106.    20 (0) | 00:00:01 |       |       | Q1, 03 | SVCP |            |
| 27.       NESTED LOOPS |                                |     4.   106.    20 (0) | 00:00:01 |       |       | Q1, 03 | SVCP |            |
PLAN_TABLE_OUTPUT
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| 28.        NESTED LOOPS |                                |     4.   256.     8 (0) | 00:00:01 |       |       | Q1, 03 | SVCP |            |
| 29.         TABLE ACCESS BY INDEX ROWID | X$ PT74MSS0WBH028JE0GUCLBK0LHM4 |     1.    22.     3 (0) | 00:00:01 |       |       | Q1, 03 | SVCP |            |
| * 30 |          INDEX RANGE SCAN | X$ PR74MSS0WBH028JE0GUCLBK0LHM4 |     1.       |     2 (0) | 00:00:01 |       |       | Q1, 03 | SVCP |            |
| 31.         ITERATOR SYSTEM PARTITION.                                |     4.   168.     5 (0) | 00:00:01 |    53.    54. Q1, 03 | SVCP |            |
| * 32 |          TABLE ACCESS BY LOCAL INDEX ROWID | INCIDENT_PATHTABLE |     4.   168.     5 (0) | 00:00:01 |    53.    54. Q1, 03 | SVCP |            |
| * 33 |           INDEX RANGE SCAN | INCIDENT_PATHTABLE_PIKEY_IX |     4.       |     4 (0) | 00:00:01 |    53.    54. Q1, 03 | SVCP |            |
| 34.        ITERATOR SYSTEM PARTITION.                                |     1.       |     2 (0) | 00:00:01 |   KEY |   KEY | Q1, 03 | SVCP |            |
| * 35 |         INDEX RANGE SCAN | INCIDENT_PATHTABLE_KEY_IX |     1.       |     2 (0) | 00:00:01 |   KEY |   KEY | Q1, 03 | SVCP |            |
| * 36 |       TABLE ACCESS BY LOCAL INDEX ROWID | INCIDENT_PATHTABLE |     1.    42.     3 (0) | 00:00:01 |     1.     1. Q1, 03 | SVCP |            |
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
PLAN_TABLE_OUTPUT
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Information of predicates (identified by the operation identity card):
---------------------------------------------------
10 - access("SYS_P9".") PATHID '=' ID')
Access (SYS_PATH_REVERSE ("PATH") 15 - > = HEXTORAW ('02582E') AND SYS_PATH_REVERSE ("PATH") < HEXTORAW ('02582EFF'))
16 - access("SYS_P11".") RID "IS 'SYS_P9'." GET RID OF"AND TBL$ OR$ IDX$ PART$ NUM ("CORPAUDLIVE". "THE INCIDENT", 0,7,65535, "SYS_P9" "." " "RID") = TBL$ OR$ IDX$ PART$ NUM ("CORPAUDLIVE". "INCIDENT_PATHTAB
THE', 0,7,65535, ROWID))
filter ("SYS_P9". "ORDER_KEY" < = 'SYS_P11' "." " ORDER_KEY' AND 'SYS_P11 '. "" ORDER_KEY "< SYS_ORDERKEY_MAXCHILD ("SYS_P9". "ORDER_KEY")) "
20 filter (SYS_XMLI_LOC_ISTEXT ("SYS_P11". "LOCATOR", "SYS_P11" "." " PATHID') = 1)
21 - access("SYS_P11".") The VALUE "= 'John')
23 filter (SYS_XMLI_LOC_ISNODE ("SYS_P9". "LOCATOR") = 1 AND SYS_OP_BLOOM_FILTER (: BF0000, "SYS_P9".) " PATHID'))
PLAN_TABLE_OUTPUT
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
24 - filter("A".") INCIDENT_DATE' > = TIMESTAMP' 2014 - 10 - 01 00:00:00.000000000 "AND"A"". "" INCIDENT_DATE"< = TIMESTAMP' 2014 - 10 - 09 00:00:00.000000000' AND
"ITEM_2" = TBL$ OR$ IDX$ PART$ NUM ("INCIDENT", 0,7,65535, "A". ROWID))
25 filter ("ITEM_4" = TBL$ OR$ IDX$ PART$ NUM ("INCIDENT", 0,7,65535, "A".) ROWID))
30 - access (SYS_PATH_REVERSE ("PATH") > = HEXTORAW('027FF9') AND SYS_PATH_REVERSE ("PATH") < HEXTORAW ('027FF9FF'))
32 filter (SYS_XMLI_LOC_ISNODE ("SYS_P2". "LOCATOR") = 1) "
33 - access("SYS_P2".") GET RID OF"="A ". ROWID AND 'SYS_P2 '. ("' PATHID '=' ID ')
35 - access("SYS_P4".") GET RID OF"="A ". ROWID AND 'SYS_P2 '. "" ORDER_KEY "< ="SYS_P4. " "" ORDER_KEY "AND"SYS_P4 ". "" ORDER_KEY "< SYS_ORDERKEY_MAXCHILD ("SYS_P2". "ORDER_KEY")) "
filter ("SYS_P4". "RID"IS "SYS_P2"." GET RID OF"AND TBL$ OR$ IDX$ PART$ NUM("INCIDENT",0,7,65535,"SYS_P2".") "RID") = TBL$ OR$ IDX$ PART$ NUM ("INCIDENT_PATHTABL
E «(, 0,7,65535, ROWID)).
36 - filter("SYS_P4".") The VALUE '= 'clark' AND SYS_XMLI_LOC_ISTEXT ("SYS_P4".' LOCATOR', 'SYS_P4 '. (("" PATHID ') = 1).
PLAN_TABLE_OUTPUT
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Note
-----
-dynamic sample used for this survey (level = 6)
69 selected lines.
Elapsed time: 00:00:00.47
SQL > spool off
Thank you
CenterB

You must create a XMLIndex with two groups:

create table actionnew)

number of action_pk

action_date timestamp

action_detail xmltype

)

partition by (range (action_date)

partition values before_2015 less (timestamp ' 2015-01-01 00:00:00 ')

, partition values jan_2015 less (timestamp ' 2015-02-01 00:00:00 ')

, partition values feb_2015 less (timestamp ' 2015-03-01 00:00:00 ')

);

create index actionnew_sxi on actionnew (action_detail)

indexType is xdb.xmlindex

local

parameters (q'~)

Group my_group_1

XMLTable actionnew_xt1

"/ audit/action_details/screen_data/tables/table/row.

path of varchar2 (100) the columns "name".

, path of surname varchar2 (100) "first name".

Group my_group_2

XMLTable actionnew_xt2

"/ audit/action_details/fields.

path of varchar2 (100) the columns "name".

, path of surname varchar2 (100) "first name".

~'

);

Select x.*

to actionnew t

xmltable)

"/ audit/action_details/screen_data/tables/table/row.

in passing t.action_detail

path of varchar2 (100) the columns "name".

, path of surname varchar2 (100) "first name".

) x

where t.action_date between timestamp ' 2015-02-01 00:00:00 '

and timestamp ' 2015-03-01 00:00:00 '

and x.forename = 'anwardo. '

and x.surname = 'gram '.

;

request done full table scan
Hai all,

10.2.0.4 on solaris 10
```
SELECT sum(RechargeForPrepaid/10000), to_date(substr (TIMESTAMP, 1,8),'YYYY/MM/DD')
FROM medt.crm_t  WHERE to_date(substr (TIMESTAMP, 1,8),'YYYY/MM/DD') >= trunc(sysdate)-1 and tradetype != '0' group by to_date(substr (TIMESTAMP, 1,8),'YYYY/MM/DD');
```
The shows to explain that it performs a table full scan on crm_t. I created indexes on the column
timestamp and tradetype too. collected stats too. but still, it makes a full table scan.

Please guide

Thank you
Kai
Obviously.

The column is named incorrectly--> timestamp is a reserved word.
It's also the wrong type--> dates should not be stored as varchar2.

Also () =
where is indexed
always removes the index.

The design of this table is a complete mess.
Drop and redesign.

You can yourself to hack and put an index of feature based on the expression, but the table will still be a disaster.
I hope that this code does not belong to a commercial application.
Me cry and me to hire a lawyer to sue the seller.

-----------
Sybrand Bakker
Senior Oracle DBA

How to avoid the full table scan?

Hello
I'm new to sql tuning. When I run the following query. Full table scan that happens and it does not use the index.
SELECT / * + FIRST_ROWS (2) * / a0.t$ ttyp, a0.t$ amnt FROM forest112 WHERE a0.t$ amnt <>: 1 AND a0.t$ dapr =: 2 AND a0.t$ tapr =: 3;
When I searched on the net, I found by changing the operator '<>' with 'NOT IN' we can make the query to use the index, but that will change the result. Is this true? What are the other changes that can be made to this query?

I think that create under index may solve your problem, because in this case, it will not hit the table and get all desired data to index itself

create index ind_1 on forest112 (tapr$ t, t$ WTSA, dapr$ t, t$ ttyp) compute statistics;

Thank you

Harman

causing trunc of the full Table Scans

I have a situtaion here where my query is this.

SQL > select count (1) in the HBSM_SM_ACCOUNT_INFO where OPTIONAL_PARM5 = 'HD' and CUST_STATUS in ('UP', "UUP") and trunc (FIRST_ACTVN_DATE) = trunc (sysdate);

COUNT (1)
----------
6

PLAN_TABLE_OUTPUT
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Hash value of plan: 3951750498

---------------------------------------------------------------------------------------------------------------
| ID | Operation | Name | Lines | Bytes | Cost (% CPU). Time | Pstart. Pstop |
---------------------------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | 1. 10. 13904 (1) | 00:02:47 |
| 1. GLOBAL TRI | 1. 10 | | | | |
| 2. SIMPLE LIST OF PARTITION. 1. 10. 13904 (1) | 00:02:47 | 12. 12.
|* 3 | TABLE ACCESS FULL | HBSM_SM_ACCOUNT_INFO | 1. 10. 13904 (1) | 00:02:47 | 12. 12.
---------------------------------------------------------------------------------------------------------------

Information of predicates (identified by the operation identity card):
---------------------------------------------------

3 filter (("CUST_STATUS" = "UP" OU "CUST_STATUS" = 'UUP') AND)
TO_DATE (INTERNAL_FUNCTION ("FIRST_ACTVN_DATE")) = TO_DATE (TO_CHAR(SYSDATE@!)))

16 selected lines.

If I remove the trunc clause in the query performance improves significantly the results are false.

SQL > select count (1) in the HBSM_SM_ACCOUNT_INFO where OPTIONAL_PARM5 = 'HD' and CUST_STATUS in ('UP', "UUP") and FIRST_ACTVN_DATE = trunc (sysdate);

COUNT (1)
----------
0

PLAN_TABLE_OUTPUT
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Hash value of plan: 454529511

---------------------------------------------------------------------------------------------------------------------------
| ID | Operation | Name | Lines | Bytes | Cost (% CPU). Time | Pstart. Pstop |
---------------------------------------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | 1. 40. 47 (0) | 00:00:01 |
|* 1 | TABLE ACCESS BY INDEX ROWID | HBSM_SM_ACCOUNT_INFO | 1. 40. 47 (0) | 00:00:01 | 12. 12.
|* 2 | INDEX RANGE SCAN | IND_FIRST_ACTVN_DATE | 51. 4 (0) | 00:00:01 |
---------------------------------------------------------------------------------------------------------------------------

Can anyone please help me by which I can get the right data, and I can also prevent such full table scans.

Unless you use a functional index, apply any function to an indexed column prevents the use of the index.

The way around it in your case is to realize that

select count(1) from HBSM_SM_ACCOUNT_INFO where OPTIONAL_PARM5='MH' and CUST_STATUS in ('UP','UUP') and trunc(FIRST_ACTVN_DATE) = trunc(sysdate)

Really asking that the FIRST_ACTVN_DATE are sometimes today. You can rewrite so as

select count(1) from HBSM_SM_ACCOUNT_INFO where OPTIONAL_PARM5='MH' and CUST_STATUS in ('UP','UUP')
and FIRST_ACTVN_DATE >= trunc(sysdate)
and FIRST_ACTVN_DATE < trunc(sysdate) + 1

Note that this may not always use the index according to the number of lines are the date of the day compared to how many are outside today's date.

Also, when you post, don't forget to put your code between

 tags and to post create table scripts and sample data inserts.

Index on non unique values in order to avoid the full table scan
I have a table with > 100 k records. The table is updated only during the race every night. All columns except one have non - unique values and I am querying the table with this request.

COL3 - non - unique values - only 40 distinct values
unique values - no - COL4 - 1000 distinct values
last_column - 100 k unique values

Select last_column in the table_name where in (...) col3 or col4 (...)

I tried to create a Bitmap index individually on col3 and col4 and also combined. However, in both cases, it performs a full table scan.

Please, help me optimize this query as it is used in the term altogether the system and the cost of the query is very high around 650.

I don't have much experience with popular indexes then all tracks.

Thank you
Sensey

Published by: user13312817 on November 7, 2011 11:32
An alternative might be to use a union instead and the 2 index:

create index my_index1 on my_table (col3, last_column) compress 1;
create index my_index2 on my_table (col4, last_column) compress 1;

Select last_column from my_table
where col3 in (...)
Union
Select last_column from my_table
where col4 (...)

In other words, if the UNION would apply here whereas in double values for last_column will be deleted.

How to improve the only table has full table scan with a lot of data and without PK
Hello world...

I have YOUR table...
CREATE YOUR TABLE
(
EMPLOYEE_NUMBER VARCHAR2 (30 BYTE) NOT NULL,
ATT_DATE DATE NOT NULL,
DATE OF DATE_TIME_IN,
DATE OF DATE_TIME_OUT,
NUMBER OF DELAY_MINUTES
NUMBER OF EARLY_EXIT_MINUTES
STATUS VARCHAR2 (20 BYTE)
)

This table contains a primary key and no clue on this subject. and coontain around 600 000 recoed.

query this table take about 5 mintes with full table scan

Select * from your.

I create indexes on Employee_No and atta_date, although there is a constarin for bith of them is not zero, but they have a duplciate value...

But even thogh the table always do full table scan...

BR
Thanks for the stats...
Well, your statistics on that table are updated.
The volume taken by the table is consistent with the number of lines you have and the average space taken by each activity.

what I propose (this is not a 'query' problem since you decide to read the ENTIRE contents of the table and you are not satisfied with the performance):
-Try this query in parallel (maybe your server will not parallelize it):
```
 select /*+ PARALLEL(x) */ * from ta x
```
- or check what are the events of theses/wait (probably the disk IO rate or the network)

REM: As SY compression could be an option to go in his direction, I repeat:
"change the type data number EMPLOYEE_NUMBER" instead of varchar2 (rebuild the table) in a way you will earn enough space (bytes/line) VS the actual duration of each lines.
Another way to reduce the space and If you insert / select in this table is finally reduce the PCTFREE, but beware the danger of this is that you will lose all the benefit if this table is updated or deleted. (it may not be the case today, but it could be in the future!)

Published by: user11268895 on July 18, 2010 16:15

best way to avoid the full table scan for clause "column is zero.
I have a query with is control null, and because of that it performs a total scan of table (in millions of rows in the table)

SELECT id, x,
LAG (id) OVER (PARTITION BY userid ORDER BY has had place, id) as p_id,.
FROM MyTable
WHERE X is ZERO

What is the best way for me to avoid the full table scan. I have indexes for the X column and other columns.

Thank you
Hi Vasif

NULL values are indexed if the indexed entry also includes a value non-zero.

If you create an index such as:

CREATE INDEX mytable_x_idx ON mytable (x, ' ');

ensure all null values for the column X are indexed and will therefore potentially use the index to search for null values, assuming of course the result set is small enough to justify the use of the index in your query.

I have spoken previously on my blog:

http://richardfoote.WordPress.com/2008/01/23/indexing-nulls-empty-spaces/

See you soon

Richard Foote
http://richardfoote.WordPress.com/

Simple query in Oracle Table in MS Access causes a full table scan.
I run a very simple query in MS ACCESS to an Oracle table attached as follows:

Select *.
EXPRESS_SERVICE_EVENTS-(EXPRESS is the name of the related table. SERVICE_EVENTS)
When executed > MyDate()

or

Select *.
EXPRESS_SERVICE_EVENTS-(EXPRESS is the name of the related table. SERVICE_EVENTS)
When executed > [Forms]! [MyForm]! [Date1]

We have more than 50 machines and this query works well on more than half of them, using an Oracle Index on the field "run." Exactly the same thing running on other machines results in a full table scan, so regardless of the index (the DB access even access all machines).

Strangely, if we write the query as follows:

Select *.
Of EXPRESS_SERVICE_EVENTS
When executed > # 2009-09-04 08:00 #.

It works fast everywhere!

Any help with this "phenominon" would be appreciated.

We did the things:
Check the locale settings of the ODBC driver, MS Access settings (as in tools-> Options), we have the latest XP and Office service packs and re-related all the Access Tables on the slow and fast machines independently).
All machines use the same version of the ODBC driver?

If you have access to Metalink, check the following note:
Note.257828.1 Scan of Table full Ext/Pub while seeking the DATE columns using the ODBC Oracle driver:

In a Word, try "bind timestamp date" option in the dsn configuration and do not forget to update the links in the table.

It will be useful,
Greg

Full table scan - condition of partition ignored
Hello world.

I ask a table partitioned, and when I hard code a condition of date on partitioned column, the query runs as expected - that is to say making reference to the partition in question.

I want to automate the application - and the date of the partition will vary each month (it is based on the last load of lots in our database from the previous month) - so I have a subquery that will get the date of the partition. The question I have is that when I run my query (including the subquery) - the explain command plan indicates that I now do a full table scan - I don't really want to. I read in some documents and came across this:

+ ' However, the optimizer do prune partitions if the SQL statement applies to a function to the partitioning (with the exception of the TO_DATE function) column ".". " +

My subquery contains several functions. Has anyone encountered this before and managed to work around? Ideally, I really need to try to find a solution that involves no PL/SQL, the query will be executed in Business Objects.

Any help or pointers greatly appreciated.

Void Query =

(SELECT TO_CHAR (TO_DATE (MAX (SUBSTR (A.PARTITION_NAME,-8)), 'YYYYMMDD'), 'YYYYMMDD') batch_date)

FROM DBA_TAB_PARTITIONS WHERE A.TABLE_OWNER = 'BUSINT_OWNER' AND A.TABLE_NAME = "TBL_FACT_DAILY_PLAN_BALANCE."

AND TO_CHAR (TO_DATE (SUBSTR(A.PARTITION_NAME,-8), 'YYYYMMDD'), 'MONTH') = TO_CHAR (ADD_MONTHS (TRUNC (SYSDATE),-1), 'MONTH'))
Ouch!... Dates in the form VARCHAR2s! This will be just one of your many and varied ;-) problems

In any case, go you could achieve this through PL/SQL, where you limit the SELECT for a partition only, use dynamic SQL Native ("EXECUTE IMMEDIATE"):
```
...
v_tab_part VARCHAR2(8);
v_sql VARCHAR2(2048);
...
BEGIN
SELECT TO_CHAR(TO_DATE(MAX(SUBSTR(A.PARTITION_NAME,-8)),'YYYYMMDD'),'YYYYMMDD')
INTO  INTO v_tab_part
FROM DBA_TAB_PARTITIONS A WHERE A.TABLE_OWNER = 'BUSINT_OWNER' AND A.TABLE_NAME = 'TBL_FACT_DAILY_PLAN_BALANCE'
AND TO_CHAR(TO_DATE(SUBSTR(A.PARTITION_NAME,-8),'YYYYMMDD'),'MONTH') = TO_CHAR(ADD_MONTHS(TRUNC(SYSDATE),-1),'MONTH');

v_sql =
'SELECT' ||
' /*+ USE_HASH (A B C D E F G) */ ' ||
...
'FROM ' ||
'TBL_FACT_DAILY_PLAN_BALANCE PARTITION (' || v_tab_part || ') C,' ||
'BCP_STG D, ' ||
...
'WHERE f.dac_end_date >= max_part.batch_date ' ||
'and B.DAS_PK = F.DAC_ACC_STATUS_FK ' ||
...
'GROUP BY ' ||
...

EXECUTE IMMEDIATE v_sql;

END;
```
However one thing, you could try prior to that would be to change the last attempt with the WITH CLAUSE of:
```
C.FDP_DATA_DATE = max_part.batch_date
```
VOY
```
C.FDP_DATA_DATE IN (max_part.batch_date)
```
Unlikely to make a difference, perhaps, but worth a try

Full table scan without sweeping particular column (CLOB data type column)
I want to select the online_bank table. This table with a column of type CLOB data. I want to select all the columns in the table, except the column type of clob data. but oracle full table, including the column analysis server type CLOB data when the query is run. It took a long time to complete the table. Please give me a solution of full table scan without analysis the CLOB data type column. How to avoid the time scanning CLOB data type column... ?
878728 wrote:
I want to select the online_bank table. This table with a column of type CLOB data. I want to select all the columns in the table, except the column type of clob data. but oracle full table, including the column analysis server type CLOB data when the query is run. It took a long time to complete the table. Please give me a solution of full table scan without analysis the CLOB data type column. How to avoid the time scanning CLOB data type column... ?

We do not have your table.
We do not have your data.
Therefore, we have no answer to your apparent mystery.

Why "FULL TABLE SCAN?

I have a table with 831 k lines and index:

CREATE TABLE "ROGADM"."ROG_LOG" (
    "LOG_ID"       NUMBER(10,0),
    "LOG_OBK_TYP"  VARCHAR2(30 BYTE),
    "LOG_OBK_ID"   VARCHAR2(200 BYTE),
    "LOG_TYP"      VARCHAR2(30 BYTE),
    "LOG_RODZAJ"   VARCHAR2(30 BYTE),
    "LOG_R_OBK_ID" VARCHAR2(200 BYTE),
    "LOG_DATA_ZDARZENIA" DATE,
    "LOG_OPIS_ZDARZENIA" VARCHAR2(4000 BYTE),
    "LOG_UTWORZYL"       VARCHAR2(30 BYTE),
    "LOG_KIEDY_UTWORZYL" DATE,
    CONSTRAINT "LOG_PK" PRIMARY KEY ("LOG_ID")
);
CREATE INDEX "ROGADM"."LOG_I" ON "ROGADM"."ROG_LOG" (
    "LOG_OBK_ID",
    "LOG_OBK_TYP",
    "LOG_TYP",
    "LOG_RODZAJ"
);
CREATE INDEX "ROGADM"."LOG_I2" ON "ROGADM"."ROG_LOG" (
    "LOG_R_OBK_ID",
    "LOG_RODZAJ"
);
CREATE UNIQUE INDEX "ROGADM"."LOG_PK" ON "ROGADM"."ROG_LOG" (
    "LOG_ID"
);

When I run of EXPLAIN PLAN for the sql:

SELECT log_obk_id FROM rog_log;

the output is

PLAN_TABLE_OUTPUT
Plan hash value: 3822058985
 
-----------------------------------------------------------------------------
| Id  | Operation         | Name    | Rows  | Bytes | Cost (%CPU)| Time     |
-----------------------------------------------------------------------------
|   0 | SELECT STATEMENT  |         |   831K|  8122K|  2240   (2)| 00:00:27 |
|   1 |  TABLE ACCESS FULL| ROG_LOG |   831K|  8122K|  2240   (2)| 00:00:27 |
-----------------------------------------------------------------------------

Why?

You have an index on the LOG_OBK_ID column. But when you select this column see you FULL TABLE SCAN and no index is used.

This is because you have not set your column as NOT NULL value column. Oracle stores a NULL value in the index. And that is why when you query the table for LOG_OBK_ID he goes to the table and does not use the index.

See the example below

SQL> create table my_test ( object_id number not null, object_type varchar2(100), object_name varchar2(100));

Table created.

SQL> create index my_test_idx on my_test(object_id, object_type);

Index created.

SQL> insert into my_test
  2  select object_id, object_type, object_name
  3    from all_objects
  4   where rownum <= 100000
  5  /

50058 rows created.

SQL> commit
  2  /

Commit complete.

SQL> exec dbms_stats.gather_table_stats('KARTHICK_PATTABIRAMAN','MY_TEST',cascade=>true)

PL/SQL procedure successfully completed.

SQL> explain plan for select object_id from my_test
  2  /

Explained.

SQL> select * from table(dbms_xplan.display)
  2  /

PLAN_TABLE_OUTPUT
--------------------------------------------------------------------------------
Plan hash value: 720752151
------------------------------------------------------------------------------------
| Id  | Operation            | Name        | Rows  | Bytes | Cost (%CPU)| Time   |
------------------------------------------------------------------------------------
PLAN_TABLE_OUTPUT
--------------------------------------------------------------------------------
|   0 | SELECT STATEMENT     |             | 50058 |   244K|    36   (0)| 00:00:01 |
|   1 |  INDEX FAST FULL SCAN| MY_TEST_IDX | 50058 |   244K|    36   (0)| 00:00:01 |
------------------------------------------------------------------------------------

8 rows selected.

See the index is used. Oracle considers the index as a Skinny table version and do a FULL scan on the INDEX and not on the TABLE.

Now, let us remove the NOT NULL constraint and see what happens.

SQL> alter table my_test modify object_id null
  2  /

Table altered.

SQL> desc my_test
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 OBJECT_ID                                          NUMBER
 OBJECT_TYPE                                        VARCHAR2(100)
 OBJECT_NAME                                        VARCHAR2(100)

SQL> exec dbms_stats.gather_table_stats('KARTHICK_PATTABIRAMAN','MY_TEST',cascade=>true)

PL/SQL procedure successfully completed.

SQL> explain plan for select object_id from my_test
  2  /

Explained.

SQL> select * from table(dbms_xplan.display)
  2  /

PLAN_TABLE_OUTPUT
--------------------------------------------------------------------------------
Plan hash value: 1615681525

-----------------------------------------------------------------------------
| Id  | Operation         | Name    | Rows  | Bytes | Cost (%CPU)| Time     |
-----------------------------------------------------------------------------
|   0 | SELECT STATEMENT  |         | 50058 |   244K|    67   (0)| 00:00:01 |
|   1 |  TABLE ACCESS FULL| MY_TEST | 50058 |   244K|    67   (0)| 00:00:01 |
-----------------------------------------------------------------------------

8 rows selected.

SQL>

See oracle now goes for FULL TABLE SCAN.

How do full table scan

Hi all
I have a table which is accesed by application every 5 seconds. Now, this table has several delete insert updates current. The table size is aprox 200 MB (high tide) and there is say 5 ranks, which will be a sentence of 20 to 30 KB. My CMS is say 2 GB. So now the stats are not met and there is no index in this table. Now I see full table scan as his wait event. Now, I want to know.
How a scan full of tabel happens Oracle load the entire 200MB of data in the SGA and then do a table scan or should just the actual size used by the table IE 20 to 30 KB.
Thank you
A

Hello

high waters is precisely the limit up to which Oracle must read to be sure that all the data has been seen, so if you have only about 30 KB of data in the table, even if the data is in the first a few blocks from the table, a complete analysis must read the 200 MB (which is not so good but takes more time to read a few blocks). (the reason is that it was once the data written in this block and it triggered the HWM),

You can reorganize the table (alter table mytable move or use DBMS_REDEFINITION so that you can do this, the application uses the table) to reset the HWM. ("If the current small" size used"is transient and if you expect the table to increase again to use 200 MB or more, don't need to reorg; do it if you are confident that the table will remain very weak)

Best regards

Brno Vroman.

The query makes a full table scan?

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