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pct free and pct used ???? [message #235986] Tue, 08 May 2007 10:52 Go to next message
gaur_poonam
Messages: 20
Registered: April 2007
Location: India
Junior Member

Here is a question taken straight from the Couchman text CD. I cant understand why the correct answer is given. I understand the meanings of pctfree / pctused, but I don't know which one is the least desirable:

"Which of the following choices identifies block space utilization settings that are never appropriate under any circumstances:

A: pctfree 5, pctused 90
B: pctfree 20, pctused 70
C: pctfree 15, pctused 80
D: pctfree 10, pctused 40

The correct answer is C. Why ? (I chose B)

Thanks..........
Re: pct free and pct used ???? [message #236089 is a reply to message #235986] Wed, 09 May 2007 00:41 Go to previous messageGo to next message
Dipali Vithalani
Messages: 278
Registered: March 2007
Location: India
Senior Member

The correct answer is C, because, the total of PCTFREE and PCTUSED should not be greater than 100.

Regards..
Re: pct free and pct used ???? [message #236108 is a reply to message #236089] Wed, 09 May 2007 01:09 Go to previous messageGo to next message
Michel Cadot
Messages: 64151
Registered: March 2007
Location: Nanterre, France, http://...
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80 + 15 = 95 < 100, afaik.

Regards
Michel
Re: pct free and pct used ???? [message #236117 is a reply to message #235986] Wed, 09 May 2007 01:27 Go to previous messageGo to next message
user82
Messages: 49
Registered: June 2006
Location: Romania
Member
For Michel Cadot.....
and also
A: 90 + 5 = 95 <100
B: 70 + 20 = 90 <100
D: 40 + 10 = 50 <100
.....
isn't it??? Could you explain this in detail...i knew the fact that PCTFREE+PCTUSED < 100 but according to this all the answers are correct...
Re: pct free and pct used ???? [message #236121 is a reply to message #236117] Wed, 09 May 2007 01:37 Go to previous messageGo to next message
Michel Cadot
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Registered: March 2007
Location: Nanterre, France, http://...
Senior Member
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user82,

I did not give an answer to the OP question, I replied to Dipali post.

Regards
Michel
Re: pct free and pct used ???? [message #236201 is a reply to message #235986] Wed, 09 May 2007 05:05 Go to previous messageGo to next message
hotmercury
Messages: 13
Registered: February 2007
Location: Mumbai
Junior Member
Heres something from the docs..."The smaller the difference between 100 and the sum of PCTFREE and PCTUSED (as in PCTUSED of 75, PCTFREE of 20), the more efficient space usage is, at some performance cost." Now, i cant see y option C would be the most inappropriate under any circumstances...!!!
Re: pct free and pct used ???? [message #236241 is a reply to message #236201] Wed, 09 May 2007 07:02 Go to previous messageGo to next message
gaur_poonam
Messages: 20
Registered: April 2007
Location: India
Junior Member

hi,
thanks to all.but i guess from,

"The smaller the difference between 100 and the sum of PCTFREE and PCTUSED (as in PCTUSED of 75, PCTFREE of 20), the more efficient space usage is, at some performance cost."

the answer is most appropriate for the efficient space usage.so its totally opposite to whats asked in qustion.


thanks.......
Re: pct free and pct used ???? [message #236249 is a reply to message #235986] Wed, 09 May 2007 07:21 Go to previous messageGo to next message
hotmercury
Messages: 13
Registered: February 2007
Location: Mumbai
Junior Member
Razz ...Michel where r u...!! How abt commenting on this.....
Re: pct free and pct used ???? [message #236253 is a reply to message #236249] Wed, 09 May 2007 07:27 Go to previous messageGo to next message
Michel Cadot
Messages: 64151
Registered: March 2007
Location: Nanterre, France, http://...
Senior Member
Account Moderator
Nothing to say.
Each value can be useful in some cases.
Each value can be desastreous in other cases.
No answer is true, no answer is wrong.
So nothing to say.
So I shut up.

Regards
Michel
Re: pct free and pct used ???? [message #236258 is a reply to message #235986] Wed, 09 May 2007 07:45 Go to previous messageGo to next message
hotmercury
Messages: 13
Registered: February 2007
Location: Mumbai
Junior Member
Hmmm....how about someone telling me the advantage of keeping the PCTUSED set to a low value..(eg: 40)... Wdnt setting a high value be a better option as the inserts are done more frequently...(ie; less than the PCTUSED..)
Re: pct free and pct used ???? [message #236643 is a reply to message #235986] Thu, 10 May 2007 08:21 Go to previous messageGo to next message
Yasir Hashmi
Messages: 304
Registered: April 2006
Senior Member
what is Mr.Couchman's explanation for the answer in ur book?
Re: pct free and pct used ???? [message #237066 is a reply to message #235986] Fri, 11 May 2007 15:10 Go to previous message
michael_bialik
Messages: 611
Registered: July 2006
Senior Member
AFAIK - with locally managed tablespaces pct_used is dead? Isn't it?

Michael
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