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Table actual size [message #563191]

Thu, 09 August 2012 07:09

savugar
Messages: 31
Registered: February 2012

Member

Which is the correct method to calculate actual data size in a table? becaue when I serach in google, I saw the below line.

"Oracle thumb rule says (actual space required for a table + 30 % space) will calculate the original space requirement for a table."

Method 1:

actual space = num_rows*avg_row_len

Method 2:

actual space = (Num of rows in a table) * (Avg_row_len) + ((Num of rows in a table) * (Avg_row_len)* 0.3)

[Updated on: Thu, 09 August 2012 07:18]

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Re: Table actual size [message #563192 is a reply to message #563191]

Thu, 09 August 2012 07:17

Michel Cadot
Messages: 54247
Registered: March 2007
Location: Nanterre, France, http://...

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Explain the second method.
Define "actual data size"; do you include Oracle overhead?

Regards
Michel

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Re: Table actual size [message #563193 is a reply to message #563192]

Thu, 09 August 2012 07:18

savugar
Messages: 31
Registered: February 2012

Member

I saw the below lines in one link.

"Oracle thumb rule says (actual space required for a table + 30 % space) will calculate the original space requirement for a table."

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Re: Table actual size [message #563199 is a reply to message #563193]

Thu, 09 August 2012 08:24

Michel Cadot
Messages: 54247
Registered: March 2007
Location: Nanterre, France, http://...

Senior Member
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Which link?
And is this what you define as "actual data size"?
Isn't the link saying it is the "space requirement for a table"?

Regards
Michel

[Updated on: Thu, 09 August 2012 08:25]

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Re: Table actual size [message #563201 is a reply to message #563199]

Thu, 09 August 2012 09:50

savugar
Messages: 31
Registered: February 2012

Member

http://dbarajabaskar.blogspot.in/2012/02/oracle-table-fragmentation-causing.html

I also not agree the 2nd method. However I just want to confirm this.

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Re: Table actual size [message #563202 is a reply to message #563201]

Thu, 09 August 2012 09:53

BlackSwan
Messages: 20110
Registered: January 2009

Senior Member

>I also not agree the 2nd method. However I just want to confirm this.
then you are free to ignore it & not use it.

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Re: Table actual size [message #563206 is a reply to message #563201]

Thu, 09 August 2012 10:30

Michel Cadot
Messages: 54247
Registered: March 2007
Location: Nanterre, France, http://...

Senior Member
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You stil didn't tell us what you mean by "actual data size"?
Without this definition any formula has a value of "UNKNOWN" (in the database logical sense).

Regards
Michel

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Re: Table actual size [message #563665 is a reply to message #563206]

Thu, 16 August 2012 07:38

msol25
Messages: 211
Registered: June 2011
Location: Mumbai

Senior Member


    SELECT   SUM(bytes)/1048576 "Size in Mb'
    FROM     USER_SEGMENTS
    WHERE    segment_name = 'enter yours table_name';

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Re: Table actual size [message #563683 is a reply to message #563665]

Thu, 16 August 2012 08:28

Michel Cadot
Messages: 54247
Registered: March 2007
Location: Nanterre, France, http://...

Senior Member
Account Moderator

What does this answer? Another topic question?

Regards
Michel

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