OraFAQ Forum: SQL & PL/SQL

Home » SQL & PL/SQL » SQL & PL/SQL » Check these!

Show: Today's Messages :: Polls :: Message Navigator
E-mail to friend

Check these! [message #232609]

Sun, 22 April 2007 04:09

AbbasA
Messages: 2
Registered: April 2007

Junior Member

Hi every body. I have some questions that I didn't find clear answers for them:
1. How can we execute a SELECT statement based on column that has no index?
2. How can we create a secondary index based on a column that has no index?
3. How can we find the size of memory given for each user for sorting?

I hope you can help me!

Regards.

Report message to a moderator

Re: Check these! [message #232611 is a reply to message #232609]

Sun, 22 April 2007 05:33

martijn
Messages: 286
Registered: December 2006
Location: Netherlands

Senior Member

AbbasA wrote on Sun, 22 April 2007 11:09

ad 1: Did you try? A column does not have to have a index to be used in a query
ad 2: You can easily look this up on the manuals http://download-uk.oracle.com/docs/cd/B19306_01/server.102/b14200/statements_5010.htm
ad 3: Memory for sorting is in the PGA (Process Global Area), assuming a dedicated server. It's controlled by the parameter sort_area_size. If the process needs more memory then sort_area_size, it will start sorting on disk (very expensive operation).

Maybe someone a bit more knowledgable can tell you some more about (3).

Report message to a moderator

Re: Check these! [message #232614 is a reply to message #232609]

Sun, 22 April 2007 07:22

Michel Cadot
Messages: 68718
Registered: March 2007
Location: Saint-Maur, France, https...

Senior Member
Account Moderator

Quote:

I have some questions that I didn't find clear answers for them

Where do you search to not find answers?

Regards
Michel

Report message to a moderator

Re: Check these! [message #232634 is a reply to message #232609]

Sun, 22 April 2007 13:33

AbbasA
Messages: 2
Registered: April 2007

Junior Member

Thanx martijn...

Martin...please don't ask me such "clever" questions!

Report message to a moderator

Re: Check these! [message #232639 is a reply to message #232634]

Sun, 22 April 2007 14:30

martijn
Messages: 286
Registered: December 2006
Location: Netherlands

Senior Member

mmmm I sense some sarcasm/cynism.

I guess you refer to my answer at question 1?

I then probably didn't understood the problem, and assumed you asked a very easy to test-your-self question.

Can you then please elaborate a little more on your first question?
Maybe then I understand it better and give you a more informative answer.

Report message to a moderator