RE: What makes Export slow ?
Using a large buffer size allows more data to be written via export (a C Program) from the database to a file. The buffer specifies the size of each write to the database. Direct=Y was added in Oracle7 and allows export to bypass the SQL communication layer and write data from the database to the export file. Generally this is used to speed up exports, however, there have been issues with constraints, etc. Large rollback segment option can only be used if you can really assure that no one is using the database and you can disable all other rollback segments. Otherwise, this option is useless. Thank You Stephen P. Karniotis Product Architect Compuware Corporation Direct: (248) 865-4350 Mobile: (248) 408-2918 Email: [EMAIL PROTECTED] Web:www.compuware.com -Original Message- Sent: Monday, May 20, 2002 2:04 PM To: Multiple recipients of list ORACLE-L Subject:RE: What makes Export slow ? On Mon, 20 May 2002, Reddy, Madhusudana wrote: Huge Buffer, commit=y, direct=y, assigning the big rollback segment should help you to have faster export , What do you mean assigning the big rollback segment? How do you do that to an export and what does it accomplish? What does COMMIT=Y do in an export? If I were the original poster, I'd just look at v$session_event for the export session after several minutes of slowness. -- Jeremiah Wilton http://www.speakeasy.net/~jwilton -Original Message- Sent: Monday, May 20, 2002 3:43 AM To: Multiple recipients of list ORACLE-L I moved my database from Solaris 7 to Solaris 8 box (Sun Fire 4800, faster processors and more memory space) I create the database with the same script that I used to for my database in the older machine, When I export my database from the older machine it was very fast and when I import to newer machine it was fast too, and when I export from new machine it is really slow (very slow), (I am using same export parameters in both servers) Can someone help with tuning tips or anything you have... : ( - The no of records are the same for both machines - v$session_wait.seconds_in_wait is more than 1 -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Jeremiah Wilton INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). The contents of this e-mail are intended for the named addressee only. It contains information that may be confidential. Unless you are the named addressee or an authorized designee, you may not copy or use it, or disclose it to anyone else. If you received it in error please notify us immediately and then destroy it. -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Karniotis, Stephen INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
What makes Export slow ?
Hi guys, I moved my database from Solaris 7 to Solaris 8 box (Sun Fire 4800, faster processors and more memory space) I create the database with the same script that I used to for my database in the older machine, When I export my database from the older machine it was very fast and when I import to newer machine it was fast too, and when I export from new machine it is really slow (very slow), (I am using same export parameters in both servers) Can someone help with tuning tips or anything you have... : ( - The no of records are the same for both machines - v$session_wait.seconds_in_wait is more than 1 Thank you -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Sinardy Xing INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
RE: What makes Export slow ?
Would you post the parameter file ?? Huge Buffer, commit=y, direct=y, assigning the big rollback segment should help you to have faster export , and also you can have a look at the DISK I/O stats ( verify the OFA is same on both the boxes ). Thanks, Madhu -Original Message- Sent: Monday, May 20, 2002 3:43 AM To: Multiple recipients of list ORACLE-L Hi guys, I moved my database from Solaris 7 to Solaris 8 box (Sun Fire 4800, faster processors and more memory space) I create the database with the same script that I used to for my database in the older machine, When I export my database from the older machine it was very fast and when I import to newer machine it was fast too, and when I export from new machine it is really slow (very slow), (I am using same export parameters in both servers) Can someone help with tuning tips or anything you have... : ( - The no of records are the same for both machines - v$session_wait.seconds_in_wait is more than 1 Thank you -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Sinardy Xing INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Reddy, Madhusudana INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
RE: What makes Export slow ?
On Mon, 20 May 2002, Reddy, Madhusudana wrote: Huge Buffer, commit=y, direct=y, assigning the big rollback segment should help you to have faster export , What do you mean assigning the big rollback segment? How do you do that to an export and what does it accomplish? What does COMMIT=Y do in an export? If I were the original poster, I'd just look at v$session_event for the export session after several minutes of slowness. -- Jeremiah Wilton http://www.speakeasy.net/~jwilton -Original Message- Sent: Monday, May 20, 2002 3:43 AM To: Multiple recipients of list ORACLE-L I moved my database from Solaris 7 to Solaris 8 box (Sun Fire 4800, faster processors and more memory space) I create the database with the same script that I used to for my database in the older machine, When I export my database from the older machine it was very fast and when I import to newer machine it was fast too, and when I export from new machine it is really slow (very slow), (I am using same export parameters in both servers) Can someone help with tuning tips or anything you have... : ( - The no of records are the same for both machines - v$session_wait.seconds_in_wait is more than 1 -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Jeremiah Wilton INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
RE: What makes Export slow ?
--- Jeremiah Wilton [EMAIL PROTECTED] wrote: On Mon, 20 May 2002, Reddy, Madhusudana wrote: Huge Buffer, commit=y, direct=y, assigning the big rollback segment should help you to have faster export , What does COMMIT=Y do in an export? it causes an error message! __ Do You Yahoo!? LAUNCH - Your Yahoo! Music Experience http://launch.yahoo.com -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Paul Baumgartel INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
RE: What makes Export slow ?
The idea of huge rollback segment is just to eliminate the contention the rollback segment. Well its not always applicable ( possible make sure all the other applications are not used), but we can create a big rollback segment and bring it on line and make other rollback segments offline, and run the export . So definitely the big rollback segment will be used. COMMIT=Y is not a parameter for export , instead good for import , its my mistake. Somewhere I have read that NFS Mounted file system will make the export slower . Thanks for your correction, Madhu -Original Message- Sent: Monday, May 20, 2002 1:04 PM To: Multiple recipients of list ORACLE-L On Mon, 20 May 2002, Reddy, Madhusudana wrote: Huge Buffer, commit=y, direct=y, assigning the big rollback segment should help you to have faster export , What do you mean assigning the big rollback segment? How do you do that to an export and what does it accomplish? What does COMMIT=Y do in an export? If I were the original poster, I'd just look at v$session_event for the export session after several minutes of slowness. -- Jeremiah Wilton http://www.speakeasy.net/~jwilton -Original Message- Sent: Monday, May 20, 2002 3:43 AM To: Multiple recipients of list ORACLE-L I moved my database from Solaris 7 to Solaris 8 box (Sun Fire 4800, faster processors and more memory space) I create the database with the same script that I used to for my database in the older machine, When I export my database from the older machine it was very fast and when I import to newer machine it was fast too, and when I export from new machine it is really slow (very slow), (I am using same export parameters in both servers) Can someone help with tuning tips or anything you have... : ( - The no of records are the same for both machines - v$session_wait.seconds_in_wait is more than 1 -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Jeremiah Wilton INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Reddy, Madhusudana INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
RE: What makes Export slow ?
On Mon, 20 May 2002, Reddy, Madhusudana wrote: The idea of huge rollback segment is just to eliminate the contention the rollback segment. Well its not always applicable ( possible make sure all the other applications are not used), but we can create a big rollback segment and bring it on line and make other rollback segments offline, and run the export . So definitely the big rollback segment will be used. Used for what? Are you talking about constructing consistent reads? If so, then that shouldn't be necessary on any significant scale if we, as you suggest, make sure all the other applications are not used. Even if concurrent access is allowed (as it should be) during export, why would constructing consistent reads from a variety of rollback segments cause contention conpared to constructing the same consistent reads from one big rollback segment? What are you trying to accomplish with the big rollback segment? What do you think the rollback segments are being used for by an export? -- Jeremiah Wilton http://www.speakeasy.net/~jwilton -Original Message- Sent: Monday, May 20, 2002 1:04 PM To: Multiple recipients of list ORACLE-L On Mon, 20 May 2002, Reddy, Madhusudana wrote: Huge Buffer, commit=y, direct=y, assigning the big rollback segment should help you to have faster export , What do you mean assigning the big rollback segment? How do you do that to an export and what does it accomplish? What does COMMIT=Y do in an export? If I were the original poster, I'd just look at v$session_event for the export session after several minutes of slowness. -- Jeremiah Wilton http://www.speakeasy.net/~jwilton -Original Message- Sent: Monday, May 20, 2002 3:43 AM To: Multiple recipients of list ORACLE-L I moved my database from Solaris 7 to Solaris 8 box (Sun Fire 4800, faster processors and more memory space) I create the database with the same script that I used to for my database in the older machine, When I export my database from the older machine it was very fast and when I import to newer machine it was fast too, and when I export from new machine it is really slow (very slow), (I am using same export parameters in both servers) Can someone help with tuning tips or anything you have... : ( - The no of records are the same for both machines - v$session_wait.seconds_in_wait is more than 1 -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Jeremiah Wilton INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
RE: What makes Export slow ?
If an expert is done with consistent = 'N' it still must preserve some information. In the beginning export runs some selects against the data dictionary and needs that data to be consistent throughout the export. If that data changes then it needs to be reconstructed from the undo generated when the data was changed. The undo is generated not by the export program, but by the programs which changed the data dictionary that export needs to keep consistent. Besides this undo data there is that being generated by normal transaction processing. Tables which are changing while an export select is being run are dependent on this rollback information for consistency. Consistent = 'N' does not stop this requirement on individual tables. It means that consistency between different tables is not enforced. There are selects being run against changing tables which are not related to the export and they too are dependent on undo information for consistent reads. What separates the needs for rollback information outlined in the second paragraph from the first is how long it must be maintained. The selects done by the export program against the data dictionary it must be maintained for the duration of the export. If your rollback segments are too small there Oracle will not be able to do so, and produce an error. How assigning a particular rollback segment would work in this case is beyond me. Ian MacGregor Stanford Linear Accelerator Center [EMAIL PROTECTED] -Original Message- Sent: Monday, May 20, 2002 2:06 PM To: Multiple recipients of list ORACLE-L On Mon, 20 May 2002, Reddy, Madhusudana wrote: The idea of huge rollback segment is just to eliminate the contention the rollback segment. Well its not always applicable ( possible make sure all the other applications are not used), but we can create a big rollback segment and bring it on line and make other rollback segments offline, and run the export . So definitely the big rollback segment will be used. Used for what? Are you talking about constructing consistent reads? If so, then that shouldn't be necessary on any significant scale if we, as you suggest, make sure all the other applications are not used. Even if concurrent access is allowed (as it should be) during export, why would constructing consistent reads from a variety of rollback segments cause contention conpared to constructing the same consistent reads from one big rollback segment? What are you trying to accomplish with the big rollback segment? What do you think the rollback segments are being used for by an export? -- Jeremiah Wilton http://www.speakeasy.net/~jwilton -Original Message- Sent: Monday, May 20, 2002 1:04 PM To: Multiple recipients of list ORACLE-L On Mon, 20 May 2002, Reddy, Madhusudana wrote: Huge Buffer, commit=y, direct=y, assigning the big rollback segment should help you to have faster export , What do you mean assigning the big rollback segment? How do you do that to an export and what does it accomplish? What does COMMIT=Y do in an export? If I were the original poster, I'd just look at v$session_event for the export session after several minutes of slowness. -- Jeremiah Wilton http://www.speakeasy.net/~jwilton -Original Message- Sent: Monday, May 20, 2002 3:43 AM To: Multiple recipients of list ORACLE-L I moved my database from Solaris 7 to Solaris 8 box (Sun Fire 4800, faster processors and more memory space) I create the database with the same script that I used to for my database in the older machine, When I export my database from the older machine it was very fast and when I import to newer machine it was fast too, and when I export from new machine it is really slow (very slow), (I am using same export parameters in both servers) Can someone help with tuning tips or anything you have... : ( - The no of records are the same for both machines - v$session_wait.seconds_in_wait is more than 1 -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Jeremiah Wilton INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: MacGregor, Ian A. INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists
