Home » RDBMS Server » Server Utilities » Difference in exports, due to DIRECT=y (Oracle 9i, 9.2.0.1.0, RHEL 2.1 AS)
Difference in exports, due to DIRECT=y [message #483420] Mon, 22 November 2010 00:28 Go to next message
jimit_shaili
Messages: 237
Registered: June 2006
Location: India, Ahmedabad
Senior Member
Dear Friends,

Herewith i'm showing my try of taking backup through different parameter available with export utility of oracle.

[1] Here i'm considering DIRECT=y
[oracle1@WBDevelop odb]$ exp pbl/pbl FILE=pbl_direct.dmp OWNER=pbl GRANTS=y ROWS=y COMPRESS=y DIRECT=y LOG=pbl.log
[oracle1@WBDevelop odb]$ ll -ltrh
-rw-r--r--    1 oracle1  oinstall     875M Nov 22 11:09 pbl_direct.dmp

[2] Here i'm eliminating DIRECT=y
[oracle1@WBDevelop odb]$ exp pbl/pbl FILE=pbl_conv.dmp OWNER=pbl GRANTS=y ROWS=y COMPRESS=y LOG=pbl.log
[oracle1@WBDevelop odb]$ ll -ltrh
-rw-r--r--    1 oracle1  oinstall     875M Nov 22 11:09 pbl_direct.dmp
-rw-r--r--    1 oracle1  oinstall     885M Nov 22 11:12 pbl_conv.dmp

As i understand DIRECT=y will bypass only the conversion and buffer storing procedure during export backup.
There should not be any change in data or compress level of data.
My question is why there is a difference of (885M-875M) 10M between two files?

Regards

Jimit
Re: Difference in exports, due to DIRECT=y [message #483428 is a reply to message #483420] Mon, 22 November 2010 00:58 Go to previous messageGo to next message
Michel Cadot
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Registered: March 2007
Location: Nanterre, France, http://...
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Difference in character sets.
Post database character set and NLS_LANG settings at export time.

Regards
Michel
Re: Difference in exports, due to DIRECT=y [message #483440 is a reply to message #483428] Mon, 22 November 2010 03:16 Go to previous messageGo to next message
jimit_shaili
Messages: 237
Registered: June 2006
Location: India, Ahmedabad
Senior Member
Dear Michel,

As per your requirement i'm giving you the details that

1)Extracting details through export log file

NLS_LANG settings at export time : Export done US71SCII character set and AL16UTF16 NCHAR character set

2) Extracting details through alert.log file

Database character set : WE8ISO8859P1

But my concern is,
In any case i'm not using or mentioning the character set, either via conventional path or using with DIRECT=y option, Is there any connection of character set with DIRECT=y (Direct Path).

Regards

Jimit
Re: Difference in exports, due to DIRECT=y [message #483455 is a reply to message #483440] Mon, 22 November 2010 04:51 Go to previous messageGo to next message
Michel Cadot
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Registered: March 2007
Location: Nanterre, France, http://...
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Quote:
In any case i'm not using or mentioning the character set,

You are, via the NLS_LANG parameter.
As far as I remember (but check in the documentation), direct mode does not apply character set conversion (but I'm not sure, this was my first idea).

Regards
Michel
Re: Difference in exports, due to DIRECT=y [message #483464 is a reply to message #483455] Mon, 22 November 2010 05:27 Go to previous messageGo to next message
jimit_shaili
Messages: 237
Registered: June 2006
Location: India, Ahmedabad
Senior Member
Dear Michel

What you suggest is right, and i've to go through the documentation about that. But my assumption is there should not be any difference in data. If i import the same in my another database which is identical installation and setup, there should not be affect my data.

Regards

Jimit
Re: Difference in exports, due to DIRECT=y [message #483476 is a reply to message #483464] Mon, 22 November 2010 06:45 Go to previous message
Michel Cadot
Messages: 67946
Registered: March 2007
Location: Nanterre, France, http://...
Senior Member
Account Moderator
No, there should not be affected.

Regards
Michel
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