what my issue is with this virtual column
CREATE TABLE C0HARPA.VCOL_TAB
(
col1 VARCHAR2(30 BYTE),
v_col1 VARCHAR2(6) GENERATED ALWAYS AS (SUBSTR(col1,1,6)) VIRTUAL
)
TABLESPACE TOOLS
[code]...
Lastly, can an index be created on a virtual column? I am thinking no since it calculated?
I Created the Security Policy as user sysadmin_vpd as follows
BEGIN
DBMS_RLS.ADD_POLICY (
object_schema => 'scott',
object_name => 'orders_tab',
policy_name => 'orders_policy',
function_schema => 'sysadmin_vpd',
policy_function => 'get_user_orders',
statement_types => 'select');
END;
After creation this policy I want to view & edit them.By default where they are saved.
Is there a way to alter an existing virtual column to set as a real column without dropping it and recreate (i have index on it, and i don't want to recreate them).
View 2 Replies View Relatedhow to know weather procedure is working or not in a database ..
how to know index is created on table or not.
I m migrating from 10g to 11g.I have doubt on virtual column.whether function based index and virtual column are same? if no means what difference between then.What are difference in their performance??
View 5 Replies View RelatedI have created queue table using below script
BEGIN
SYS.DBMS_AQADM.CREATE_QUEUE_TABLE (
QUEUE_TABLE => 'scott.NG_MSG_QUEUE_TBL',
QUEUE_PAYLOAD_TYPE => 'SYS.AQ$_JMS_TEXT_MESSAGE',
COMPATIBLE => '10.0.0',
[code].......
Indexes
--------
INDEX_NAME TABLESPACE_NAME
------------------------------ --------------------------
AQ$_NG_MSG_QUEUE_TBL_T MEDIUM_DATA
AQ$_NG_MSG_QUEUE_TBL_I MEDIUM_DATA
SYS_IL0001100359C00037$$ MEDIUM_DATA
SYS_IL0001100359C00040$$ MEDIUM_DATA
SYS_IL0001100359C00041$$ MEDIUM_DATA
SYS_C0073180 MEDIUM_DATA
I want all the index to be created in different tablespace like 'medium_index. can we specify tablespace for index when we are creating queue table.
DT1 is a column of date datatype and there is no index created on the table
I want to add the below lines in the sql
TO_CHAR(DT1,'YYYY') BETWEEN '2005' AND '2009'
Which one should I use in where condition to query and why?
1. TO_CHAR(DT1,'YYYY') BETWEEN '2005' AND '2009'
2. DT1 BETWEEN '01/01/2005' AND '31/12/2009' (as NLS date format will not change)
3. DT1 BETWEEN to_date('01/01/2005','dd/mm/yyyy') AND ('31/12/2009' ,'dd/mm/yyyy')
Does know why I am getting ORA-01733- virtual column not allowed here Following :
CREATE TABLE EMPL
(
EMP_ID NUMBER(10),
CNT NUMBER(10)
)
insert into empl(EMP_ID)
values(1)
[code]....
ORA-01733- virtual column not allowed here
SELECT department_id
FROM (SELECT department_id
FROM employees
UNION
SELECT department_id
FROM employees_old )
WHERE department_id=100;
[code]....
The index has been created on both depart_id for the two tables. The only difference between the two I observed was the 1 recursive call for the 1st sql.and also, one additional view in the plan.There is a little difference in bytes sent over the network.
Statistics
----------------------------------------------------------
0 recursive calls
0 db block gets
6 consistent gets
0 physical reads
0 redo size
[code]....
Is there any performance impact you find in those above two sqls if you compare?
How I can build a query with conditions and calculations? E.g. I've got this table
Start | End | Working Place | Mandatory
------------------------------------------------------------------------------------
01-JAN-13 | 11-JAN-13 | Office | 1
14-JAN-13 | 25-JAN-13 | Home Office | 0
04-MRZ-13| 15-MRZ-13 | Office | 0
11-FEB-13 | 22-FEB-13 | Office | 1
Now if column working place=Office and column mandatory=0
the new column "price" has to calculate: (End-Start)* $25.00
and if working place=Office and column mandatory=1
the "price" column has to calculate: (End-Start)* $20.60
else $0.00
I tried it with the case statement but I didn't know how to calculate my values and display it to the virtual column "price".
Something like
case
when Working_Place = 'Office' and Mandatory=1
then ...
else '0.00'
end as PRICE
?????
Or is it not possible?
I am having issue with IMPDP on ORACLE VIRTUAL COLUMNS.I am having following table with Virtual column defined with Not null. Expdp is fine without any issue.
DDL :
------
CREATE TABLE alert_hist
(
alertky INTEGER NOT NULL,
alertcreatedttm TIMESTAMP(6) DEFAULT systimestamp NOT NULL,
alertcreatedt DATE GENERATED ALWAYS AS (To_date(Trunc("alertcreatedttm"))) VIRTUAL NOT NULL
When I do the import (IMPDP) it got failed with the following error.
. . imported "TESTSCHEMA"."VALART" 359.1 KB 4536 rows
ORA-31693: Table data object "TESTSCHEMA"."ALERT_HIST" failed to load/unload and is being skipped due to error:
ORA-39097: Data Pump job encountered unexpected error -1
After that I dropped the Virtual Not null column and recreated that column with Nullable.
DDL :
-----
alter table alert_hist drop column alertcreatedt;
alter table alert_hist add alertcreatedt DATE GENERATED ALWAYS AS (To_date(Trunc("alertcreatedttm"))) VIRTUAL;
After that I took the expdp and impdp , it went fine with out any issue.
is there some performance/access difference between a bitmap index on a number column and char(1) column? Both columns are not null with a default value.My application has a querie like this:
select ass.column20, ass.column30from table_a pucinner join table_b asson ass.column1 = puc.column1where pc.column_char = 'S'and ass.column_char02 = 'P'
If I create a bitmap index on column "column_char", the access plan is not changed. But changing the column datatype to number(1) and obviously the values, the index is accessed and the cost decreases.This table has 4.000.000 rows. Oracle 11.2.0.2SO
Is there a way to find when was a database role created and who has created?
View 5 Replies View Relatedtell me if a REFRESH GROUP is automatically created when a materialized view is created?
View 3 Replies View RelatedI have a table with column A which contains very few null values. I need to select these rows. I am considering two options:
a) create function based index on NVL(A, 0) and use this in where clause NVL(A, 0)=0 (column doesn't have values 0)
b) create function based index on NVL2(A, 0, NULL) and and use this in where clause NVL2(A, 0, NULL) = 0
First idea was option A. But I realized in option B the index will be much smaller, because most of values of column A isn't NULL so NVL2 will return NULL and index will not have as much leafs as in NVL. It is good idea to use NVL2? Is there any against to use option B instead of A?
I have created one unique index on one column of my table. Now i would like to add one more column in the same index without dropping the index.
SQL > CREATE TABLE DEBUG_TABLE
2 (
3 SLNO NUMBER,
4 MESSAGE VARCHAR2(4000 BYTE),
5 CREATED_DATE DATE DEFAULT SYSDATE,
6 CREATED_TIME TIMESTAMP(6) DEFAULT SYSDATE
7 );
Table created.
SQL > CREATE UNIQUE INDEX index_debug1 ON debug_table (SLNO);
Index created.
SQL > ALTER INDEX index_debug1 ADD COLUMN MESSAGE;
ALTER INDEX index_debug1 ADD COLUMN MESSAGE
*
ERROR at line 1:
ORA-02243: invalid ALTER INDEX or ALTER MATERIALIZED VIEW option
SQL >
If my query is under execution and I want to make an index on a column which is very much needed by my query. Will a simple index solve the purpose or is there any extra keyword required ?
View 2 Replies View RelatedIs the index suggested on the date column.
Here is the nature of the date column in my case:
1. The table populates with 1000's of records every day with date being always incremental (current date).
2. The search criteria from the weba application (ADF) is based on the date, user gives the range.
3. From ADF I am referring to it as sql.Timestamp when building the query.
Does Index suggested on the date column here and if so what type of index ?
I currently have a 5 column index on a table with over 2 billion records (paritioned on created_date (weekly) that is not very effective.I am contemplating replacing this 5 key index and creating a new single column index made up by hashing of all the 5 five columns.
Is this a wise stratgey? How can I implement this so it is most effective and I dont shoot myself in the foot?
I have a table with, for example, three columns: A, B,C.
I execute on this table only one select: CODESELECT * FROM TABLE WHERE A = :1 AND B=:2
Column A has a lot of distinct values (numbers), but B can have only two values: 'Y' or 'N' (cardinality about 50%/50%). It is worth to create index on two columns: A, B? Does query using index on A column will be much slower than using index on A, B?
I have in my database (OLTP-System) a table with about 6000000 records and a zise of about 2GB.
the way to create multi_column indexes on the table?
What are the rule to define the best-position of a column in an index?
index_1(col_1,Col_2,col_3) and not [ (col_1,Col_3,col_2) or (col_2,Col_3,col_1) or (col_2,Col_1,col_3) or (col_3,Col_2,col_1) or (col_3,Col_1,col_2) ] ?
I am creating an index in program and then drop the index at the end of the program. Some times due to some problem if the index could not be dropped and the user again runs the program then we get the error
ORA-01408 Index already exist on the column.
how I can get away with this error or how I can check whether the index with the same columns exits prior to creating an index.
Is there any command like
Create or replace index.....
explain slow performance of multicolumn indexes on oracle 11g R2 observed in the following scenario? A multi-column index (b-tree index) not partitioned, not unique, not reversed with 3 columns.
A series of queries are run using all 3 columns. The performance hit comes when the first order column values changes. So, maybe after 10 select queries the value changes. The 2nd and 3rd order columns are changing throughout the series of select calls, but no performance bottleneck it hit then.
here is my query
SELECT CURRENTSTEP
FROM (SELECT ( WFENTRY.NAME
|| ','
|| CURRENTSTEP.STEP_ID
) AS CURRENTSTEP,
(CASE
WHEN WFENTRY.NAME IN
[Code]...
in this query I am concatenating tow columns , I use this query as a sub query in my other queries and filter the results with and CURRENTSTEP = ?
here is how I use it
select
sys_audit_id
from
( SELECT
*
FROM
(SELECT
F.FINDING_NUMBER,
[Code]....
I saw adding this as a subquery with the filter and CURRENTSTEP = ? is slowing my query very much , as this is a derived column i cannot add index then how to improve performance for this subquery ?
I have a table A with a column B timestamp(6). The tables contains around 300000 rows..I have created index 'idx' on the column B.When i compare column 'B' with systimestamp, it does not use the index, whereas if i compare 'B' with sysdate it uses the index.
Eg :
select count(*) from a where b<=sysdate;
The above used the index 'idx' and executed in 1 second
select count(*) from a where b<=systimestamp;
The above does not use the index and executed in 19 seconds.
Version Info: 11.2 on Solaris 10
I have a partitioned table like below. I want to create a B-Tree index on SALES_RGN column which is neither the part of Primary key or the Partitioned key. Should I create this index as local or Global ?
CREATE TABLE sales_dtl
(
txn_id number (9),
salesman_id number(5),
salesman_name varchar2(30),
sales_rgn varchar2(10), -----------------------------> This column needs to be indexed
sales_amount number(10),
sales_date date,
constraint pk_sales_dtl primary key (txn_id)
[code]....
We have a table called address and having the address fields and city ,state etc. The table will store huge amount of data .We need to query on the table. I would like to know how can we fasten the query and improve the performance of the query by creating index on these columns...Query is given below . note that the nullable columns can have data
SELECT *
FROM address
WHERE address1 = 'a'
[Code]....
I'm altering a column length to increase the size and getting "ORA-30556: functional index is defined on the column to be modified".
On searching more about this error, it seems like the function index must be dropped before altering the column.The table I'm dealing with is huge.
Question 1:In case of dropping and recreating the index, should the following steps be done:
- Drop Index
- Alter the column to increase the size
- Recreate the index with NOLOGGING and NOPARALLEL clause
- ALTER INDEX to turn on LOGGING
- Gather Statistics on that index
Question 2:Is there anything else that should be done when the index is dropped and re-created?
Question 3:What are the side-effects of carrying out the above steps in a huge table with around 15 million rows?
Question 4:Would it work if I disable the index, alter the column and reenable the index?Do I have to rebuild the index and gather Stats upon reenabling it?
I need to create a composite unique index on varchar2, number and CLOB column. I haven't used such index before that have the CLOB column indexing. I found the below link related to CLOB indexing...
[URL]......
Links from where I can get related info. Also I would like to know the impact of such index on performance. I have to store and process around 50 million records in such a way, will it be beneficial to use this index?
I have an index on column of table which of data type varchar2. While selecting data from that table I am using following scenarios in where on the indexed column
like '%abc%'
like 'abc%'
like '&abc'
Will be the corresponding index will be for those cases?
