What is the difference between these two?
I am new here and I am not sure if I am posting this in the correct place. But I have recently started studying to be a programmer but because there is so much out there between these two I am getting more and more confused about how to answer this. Could someone please answer these so I can at least...
DDL is used to create, alter and truncate
DML is used to insert, update, delete and drop
DDL means "Data Definition Language". SELECT, UPDATE, INSERT belong to DML, which is "Data Modification Language". DDL is all the other commands -- for example, CREATE TABLE.
What are the initial steps to follow a database backup and job scheduling ?
Oracle - change columns to row
What is the query to change the rows into column and columns into row
Alter table A add column address1 varchar2(10);
Unsing Pivot Query
How to calculate the row length?
You can make use of VSIZE function to get the number of bytes in the internal representation of individual field. However this cannot be applied on fields that has BLOB data type and in such case you have to use dbms_lob.getlength function on BLOB data type field.
In what situation you have to prefer offline and online backups ?
Online backup also known as hot backup / open backup can be performed even the database is open and while users are working and is available for read and write activity. To perform Online backup, the ...
How will you find-out if your database is using recovery catalog or not?
There are few ways through which you would find if your database uses recovery catalog: Check backup scripts and findout if the scripts are making any connection to a recovery catalog. Check tnsnames...
Why we use sort_area_size parameter in init.Ora file?Kindly let me know?
SORT_AREA_SIZE is one of the deferred Oracle Server Parameters which is set in init.ora. Its value as bytes (integer) sets the size of in-memory sort work area. The default is 64K and the maximum valu...
Should you take the backup of logfiles if the database is running in archivelog mode?
Yes We can Take of Controlfile Online Mode Just
Fire The Command alter database backup controlfile trace And
alter database backup controlfile as trace '/Location where u want 2 take backup of ctlfile/';
No, we can not take backup of redo log files even database is running in archive log mode because of inconsistency
How to recover the datafile without having backup?
Take cold backup and recover
just create the datafile with same location mention in ur controlfile and recover the datafile ... Its simple.
alter database create datafile 'and give the datafile location and /name' by using this command we can recover the datafile without backup also
How do you show Oracle free sga memory?
show sga;
we can see the memory of SGA space
What is the difference between database refresh and database cloning
Whats the process of refresh ? ( I mean steps). Do you export/import or we take a differential backup and restore on test DB ? Any links to an article will be of great help.
Hi, There is little diff between them. First we clone the d.b totally(homepath,datafiles,data.....etc) from Prod to Test, where as in D.B Refresh we just refresh the additional data which is in p...
For this assignment task you will design a database for capturing student’s assessments marks and estimate the required amount of space. suppose we suppose that there are 5000 students at our institution and that on average each student registers for 5 courses in a semester design a database that...
How to use "alter database begin backup;" command in Oracle 9i.
1- When BEGIN BACKUP is issued: The hot backup flag in the datafile headers is set, so that the copy is identified to be a hot backup copy. This is to manage the backup consistency issue when the cop...
Sql>alter database begin backup;The above query is used to freeze the header of all datafiles belongs to tablespace in that particular database.Freeze means lock i.e during backup no data's wil...
If have 50 inactive session and I want to to kill all session at once tell me the procedure to kill all 50 session at once
in our project to kill all the inactive session we use the following script.. run the sql script given below it will give u all inactive sessions sid and serial no and redirect output to (inactive_kil...
How to see some selected lines in alert log file in UNIX environment. like tail -100f alert_sid.Log we can see only 100 lines but I need to see the lines between 300 to 500 from down .
Assuming you need lines 20 to 40,
sed -n '20,40p' file_name
or
awk 'FNR>=20 && FNR<=40' file
Hope it will help!
Order By is a keyword which is using for sort the table records either ascending or desending.For eg,for ascending,Select emp_name,emp_identity from emp order by emp_identity;Select emp_name...
contents or data of the table can be sorted by using clause ORDER BY in SELECT statement.By default the table is in ASCENDING order.SYN: SELECT * from [table name] &...
How will you determine the number of connections connected to your database?
We can also see these connections on Activity monitor. But you need permissions to see it.
We can determine the number of connections by using this - SELECT COUNT(*) FROM v$session;
Do you need a commit after DDL statements?
There is no need to issue commit command after executing DDL statements as the DDL statements are commited automatically
Dear Mam/Sir ,
NO NEED TO COMMIT AGAIN USING DDL STATEMENTS .
How to schedule the backup with cron at LINUX ?
I will refer predominantly to Relational DBMS. In a file system, data is contained in a flattened structure that is often a variable length structure. For example, a shipment received could contain th...