I wanted to know the consequences of adding a DEFAULT value to an existing column in a table.I understand that when you add a DEFAULT value to a column which is Nullable, Oracle updates all the null values for the column to the DEFAULT value, generating a lot of undo/redo data.
Is adding a DEFAULT value to a NOT NULL column a problem? As the column is NOT NULL, an update would not be done, so no undo/redo data will be generated.But will this cause a whole table scan? Is this advisable?
CREATE OR REPLACE Procedure Updatetdef_normal_ranges ( i_tdef_range_id in number, i_user_change_id in number default -1, i_norm_range_low in number default NULL,
[Code]....
EXCEPTION
WHEN OTHERS THEN raise_application_error(-20001,'An error was encountered - '||SQLCODE||' -ERROR- '||SQLERRM); END Updatetdef_normal_ranges;
* ERROR at line 1: ORA-06550: line 1, column 7: PLS-00306: wrong number or types of arguments in call to 'UPDATETDEF_NORMAL_RANGES' ORA-06550: line 1, column 7: PL/SQL: Statement ignored
If I replace the update statement with dbms_output statement this procedure works fine.
i am practicing to get Dynamic columns as i have learnt from Orafaq SQL/PLSQL forum .i am using Default EMP table...first one is running smoothly as below:
For example, initially I created the reprot source as select c1, c2, c3 from t; later I added c4. But i was unable to figure out how to make c1, c2, c3, c4 become default displayed columns. I always have to click Action -> Select Columns, then move C4 from "Do not Display" to "Display in Report".
I want to create a report by using one field and one text as columns name in layout but display the all the columns. I mention the 5 column names in query.how can I write function in summary column.
I am running a fairly busy Oracle 10gR2 DB, one of the tables has about 120 columns and this table receives on average 1500 insertions per second. The table is partitioned and the partitioning is based on the most important of the two timestamp columns. There are two timestamps, they hold different times.
Out of these 120 columns, about 15 need to be indexed. Out of the 15 two of them are timestamp, at least one of these two timestamp columns is always in the where clause the queries.
Now the challenge is, the queries we run can have any combination of the 13 other columns + one timestamp. In reality the queries never have more than 7 or 8 columns in the where clause but even if we had only 4 columns in the where clause we would still have the same problem.
So if I create one concatenated index for all these columns it will not be very efficient because after the 4th or 5th column the sorting would no longer be very useful and I believe the optimiser would simply not use the rest of the index. So queries that use the leading columns of the index in sequence work well, but if I need to query the 10th column the I have performance issues.
Now, if I create multiple single column indexes oracle will have to work a lot harder to maintain all these indexes and it will create performance issues (I have tried that). Besides, if I have multiple single column indexes the optimiser will do nested loops twice or three times and will hit only the first few columns of the where clause so I think it will kind of be the same as the long concatenated index.
What I am trying to do is exactly what the Bitmap index would do, it would be very good if I could use the AND condition that a Bitmap index uses. This way I could have N number of single column indexes which the optimiser could pick from and serve the query with exactly the ones it needs. But unfortunately using the Bitmap index here is not an option given the large amount of inserts that I get on this table.
I have been looking for alternatives, I have considered creating multiple shorter concatenated indexes but this still would not address the issue since many queries would still not be served properly and therefore would take a very long time to complete.
What I had in mind would be some sort of multidimensional index, I am not even sure if such thing exists. But essentially it would be some sort of index that could serve a query efficiently regardless of the fact that the where clause has the 1st, 3rd and last columns of the index.
So considering how widely used Oracle is and how many super large databases there are out there, this problem must be common.
I have 8 columns. Some of them might be null.I want to display all 8 columns in my result. Not null columns will be first and null at the end.Here is a sample data :
I am working on forms 6i. I have set where condition in pre-query of a trigger, my requirement is, in post-query, i want to delete the where condition.
pre-query:
set_block_property('HEADER_S',default_where,'STATUS IN (select meaning from XXSMCQSS_LOOKUP_VALUES where lookup_type=''CONCESSION STATUS CODES'' and primary_flag=''N'' )');
post_query: I want to delete this where condition, i just want make execute query normal by removing the where condition.
In my point of view, deferral FK (DFK) are stronger than non-deferral FK (NDFK). In other words, every NDFK can be moved to DFK. Is there a performance issue ?
I am trying to find out if there is a definite way to find out (by querying database) which database users have been created by Oracle (either during installation or as part of patching or adding new feature) and which database users have been created by DBAs.
I have looked into the documentation but could not find anything relevant. Ideally, I would like to know if this can be done for any versions starting from 9iR2.
I am not sure but may be I need to set long size before running above query. But when I try to set long size gives below error. "The output from DBMS_METADATA.GET_DDL is a LONG datatype. When using SQL*Plus, your output may be truncated by default. Issue the following SQL*Plus command before issuing the
DBMS_METADATA.GET_DDL statement to ensure that your output is not truncated:"SQL> SET LONG 9999error: Unhandled SET statement: "SET LONG 9999"
I would like to know the reason why the database is on unencrypted format by default,there must be some reason behind this, i hear from someone that encrypted data degrade performance thats the reasons its on unencrypted format by default.
I am using Forms 6i.I have a Radio Group, where in I have specified Intial value for it. Previously it was populating properly, But when I have added some code to fix a bug. The radio group starts behaving strange. It doesnt show defaulted value.The code what i put is not even related to the radio group.
I Just got Oracle 9i installed. But can not login . What are the Default username and password for "Oracle9i Discoverer Administrator" and other Developers Suite apps?
Also What URL should i type to access the "iSQL *PLUS" through my browser, so that i can execute my SQL statements.
Is there any property that can be set at design time or dynamically altered during runtime about the default mode in which a form opens? I have created a new FORM in Forms 6i and it opens in the Enter-Query mode. I do not want to open it in the Enter-Query mode. This is because I will be doing my own execute_query on some click of a button in the form. How do I alter this Enter-Query mode in which the form opens?
I have a table as below. This table is not partitioned.
create table t1 ( d1 date, n1 number not null );
[Code]....
I took an export dump of the above table and after that I renamed the table t1 to t1_old. Then I recreated the table as below with a default constraint on d1 field.
create table t1 ( d1 date default to_date('01/01/1100','DD/MM/YYYY','NLS_CALENDAR=GREGORIAN'), n1 number not null
[Code]....
But the problem here is the data import is taking too much time than what I expected. I can't afford a maxvalue partition here as of my DBA team mentioned if you add maxvalue partition adding partition later in a stage is difficult on this table
apply in this scenario and make the import faster. I am using oracle 10.2.0.1.0 version.
