RE: MUST read Oracle Architecture - Abrief Intro
yes , but time based incomplete recovery could create problems if he doesnt take a full backup after the os-time-change . -Original Message- Sent: Wednesday, July 24, 2002 6:39 PM To: Multiple recipients of list ORACLE-L Oracle has no concept wrt. the date time of Operating System for running individually as a product. It just takes the timestamp in certain DML's while updating and inserting the rows having DATE as datatype. Nothing more than this. Oracle works on the mechanism of SCN ie. System Change Number which gets monotonically incremented one by one after every commit takes place. It has nothing to do wrt. the OS time. When the Oracle engine gets started the control file reads the location of datafiles and redo logs and the latest SCN is read and compared with those present in datafiles aand redo logs. If the SCN is not matched menas the database was abnormally shut down and need thread recovery. Smon does this task independently and roll forwards the txn's which were left in the buffer cache and were not pushed back to d.files during checkpoint process. These txn's were committed at the user end. Now the ones which were not committed would be rolled back internally by Oracle b'ground process SMON or Server Process initiated by user process and would rollback the blocks who soever touches them first. A little bit of ARCHITECTURE OF ORACLE .. Bye for now. No problems at the time lagging behind or time forwarding of the OS -Original Message- Sent: Wednesday, July 24, 2002 6:00 PM To: Multiple recipients of list ORACLE-L Oracle will continue to work fine (as it uses SCN numbers for consistency and transaction logging rather than dates). However, if you have any apps which use timestamps in the data, then I'd do some more investigation for the ramnifications on the application logic side... -Original Message- Sent: Wednesday, July 24, 2002 7:13 AM To: Multiple recipients of list ORACLE-L If you can take the database down for 1.25 hours. I will hesitate to startup the database with time less then last closing time. Yechiel Adar Mehish - Original Message - To: Multiple recipients of list ORACLE-L [EMAIL PROTECTED] Sent: Monday, July 22, 2002 8:33 PM Hi Guys, I need to put one hour back for my OS(aix) So How will my database(7.3) handle this?? What steps I have to take?? Any light regarding that?? Thanks in advance peter. _ Chat with friends online, try MSN Messenger: http://messenger.msn.com -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Peter R 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: Yechiel Adar 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: Glenn Travis 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: Vikas Khanna 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
Re: MUST read Oracle Architecture - Abrief Intro
I think that you will understand it better if you consider 2 scenario's: 1) RMAN backup from time 13:00 is newer then the backup taken at 13:45. 2) You get Enron accounting when the feds discover that invoice number 123 was issued after invoice 124. There are a lot of things, application and / or system, that can go wrong in this situation. To be on the safe side shut the database down for 1.25 hours. Yechiel Adar Mehish - Original Message - To: Multiple recipients of list ORACLE-L [EMAIL PROTECTED] Sent: Wednesday, July 24, 2002 3:38 PM yes , but time based incomplete recovery could create problems if he doesnt take a full backup after the os-time-change . -Original Message- Sent: Wednesday, July 24, 2002 6:39 PM To: Multiple recipients of list ORACLE-L Oracle has no concept wrt. the date time of Operating System for running individually as a product. It just takes the timestamp in certain DML's while updating and inserting the rows having DATE as datatype. Nothing more than this. Oracle works on the mechanism of SCN ie. System Change Number which gets monotonically incremented one by one after every commit takes place. It has nothing to do wrt. the OS time. When the Oracle engine gets started the control file reads the location of datafiles and redo logs and the latest SCN is read and compared with those present in datafiles aand redo logs. If the SCN is not matched menas the database was abnormally shut down and need thread recovery. Smon does this task independently and roll forwards the txn's which were left in the buffer cache and were not pushed back to d.files during checkpoint process. These txn's were committed at the user end. Now the ones which were not committed would be rolled back internally by Oracle b'ground process SMON or Server Process initiated by user process and would rollback the blocks who soever touches them first. A little bit of ARCHITECTURE OF ORACLE .. Bye for now. No problems at the time lagging behind or time forwarding of the OS -Original Message- Sent: Wednesday, July 24, 2002 6:00 PM To: Multiple recipients of list ORACLE-L Oracle will continue to work fine (as it uses SCN numbers for consistency and transaction logging rather than dates). However, if you have any apps which use timestamps in the data, then I'd do some more investigation for the ramnifications on the application logic side... -Original Message- Sent: Wednesday, July 24, 2002 7:13 AM To: Multiple recipients of list ORACLE-L If you can take the database down for 1.25 hours. I will hesitate to startup the database with time less then last closing time. Yechiel Adar Mehish - Original Message - To: Multiple recipients of list ORACLE-L [EMAIL PROTECTED] Sent: Monday, July 22, 2002 8:33 PM Hi Guys, I need to put one hour back for my OS(aix) So How will my database(7.3) handle this?? What steps I have to take?? Any light regarding that?? Thanks in advance peter. _ Chat with friends online, try MSN Messenger: http://messenger.msn.com -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Peter R 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: Yechiel Adar 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: Glenn Travis 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
RE: MUST read Oracle Architecture - Abrief Intro
Shut the database DOWN for 1.25 hours? Who in the heck can afford THAT! You are *way* off base my friend. If I suggested to my client that they need to shut the database down because of a time change, they would send me out on a rail - and I would deserve it. Bad idea. Tom Mercadante Oracle Certified Professional -Original Message- Sent: Wednesday, July 24, 2002 12:08 PM To: Multiple recipients of list ORACLE-L I think that you will understand it better if you consider 2 scenario's: 1) RMAN backup from time 13:00 is newer then the backup taken at 13:45. 2) You get Enron accounting when the feds discover that invoice number 123 was issued after invoice 124. There are a lot of things, application and / or system, that can go wrong in this situation. To be on the safe side shut the database down for 1.25 hours. Yechiel Adar Mehish - Original Message - To: Multiple recipients of list ORACLE-L [EMAIL PROTECTED] Sent: Wednesday, July 24, 2002 3:38 PM yes , but time based incomplete recovery could create problems if he doesnt take a full backup after the os-time-change . -Original Message- Sent: Wednesday, July 24, 2002 6:39 PM To: Multiple recipients of list ORACLE-L Oracle has no concept wrt. the date time of Operating System for running individually as a product. It just takes the timestamp in certain DML's while updating and inserting the rows having DATE as datatype. Nothing more than this. Oracle works on the mechanism of SCN ie. System Change Number which gets monotonically incremented one by one after every commit takes place. It has nothing to do wrt. the OS time. When the Oracle engine gets started the control file reads the location of datafiles and redo logs and the latest SCN is read and compared with those present in datafiles aand redo logs. If the SCN is not matched menas the database was abnormally shut down and need thread recovery. Smon does this task independently and roll forwards the txn's which were left in the buffer cache and were not pushed back to d.files during checkpoint process. These txn's were committed at the user end. Now the ones which were not committed would be rolled back internally by Oracle b'ground process SMON or Server Process initiated by user process and would rollback the blocks who soever touches them first. A little bit of ARCHITECTURE OF ORACLE .. Bye for now. No problems at the time lagging behind or time forwarding of the OS -Original Message- Sent: Wednesday, July 24, 2002 6:00 PM To: Multiple recipients of list ORACLE-L Oracle will continue to work fine (as it uses SCN numbers for consistency and transaction logging rather than dates). However, if you have any apps which use timestamps in the data, then I'd do some more investigation for the ramnifications on the application logic side... -Original Message- Sent: Wednesday, July 24, 2002 7:13 AM To: Multiple recipients of list ORACLE-L If you can take the database down for 1.25 hours. I will hesitate to startup the database with time less then last closing time. Yechiel Adar Mehish - Original Message - To: Multiple recipients of list ORACLE-L [EMAIL PROTECTED] Sent: Monday, July 22, 2002 8:33 PM Hi Guys, I need to put one hour back for my OS(aix) So How will my database(7.3) handle this?? What steps I have to take?? Any light regarding that?? Thanks in advance peter. _ Chat with friends online, try MSN Messenger: http://messenger.msn.com -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Peter R 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: Yechiel Adar 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
RE: MUST read Oracle Architecture - Abrief Intro
I imagine it would depend on the application. Some people are stuck working on 24x7 databases, others are lucky enough to have a life. :) --Walt Weaver Bozeman, Montana -Original Message- Sent: Wednesday, July 24, 2002 10:44 AM To: Multiple recipients of list ORACLE-L Shut the database DOWN for 1.25 hours? Who in the heck can afford THAT! You are *way* off base my friend. If I suggested to my client that they need to shut the database down because of a time change, they would send me out on a rail - and I would deserve it. Bad idea. Tom Mercadante Oracle Certified Professional -Original Message- Sent: Wednesday, July 24, 2002 12:08 PM To: Multiple recipients of list ORACLE-L I think that you will understand it better if you consider 2 scenario's: 1) RMAN backup from time 13:00 is newer then the backup taken at 13:45. 2) You get Enron accounting when the feds discover that invoice number 123 was issued after invoice 124. There are a lot of things, application and / or system, that can go wrong in this situation. To be on the safe side shut the database down for 1.25 hours. Yechiel Adar Mehish - Original Message - To: Multiple recipients of list ORACLE-L [EMAIL PROTECTED] Sent: Wednesday, July 24, 2002 3:38 PM yes , but time based incomplete recovery could create problems if he doesnt take a full backup after the os-time-change . -Original Message- Sent: Wednesday, July 24, 2002 6:39 PM To: Multiple recipients of list ORACLE-L Oracle has no concept wrt. the date time of Operating System for running individually as a product. It just takes the timestamp in certain DML's while updating and inserting the rows having DATE as datatype. Nothing more than this. Oracle works on the mechanism of SCN ie. System Change Number which gets monotonically incremented one by one after every commit takes place. It has nothing to do wrt. the OS time. When the Oracle engine gets started the control file reads the location of datafiles and redo logs and the latest SCN is read and compared with those present in datafiles aand redo logs. If the SCN is not matched menas the database was abnormally shut down and need thread recovery. Smon does this task independently and roll forwards the txn's which were left in the buffer cache and were not pushed back to d.files during checkpoint process. These txn's were committed at the user end. Now the ones which were not committed would be rolled back internally by Oracle b'ground process SMON or Server Process initiated by user process and would rollback the blocks who soever touches them first. A little bit of ARCHITECTURE OF ORACLE .. Bye for now. No problems at the time lagging behind or time forwarding of the OS -Original Message- Sent: Wednesday, July 24, 2002 6:00 PM To: Multiple recipients of list ORACLE-L Oracle will continue to work fine (as it uses SCN numbers for consistency and transaction logging rather than dates). However, if you have any apps which use timestamps in the data, then I'd do some more investigation for the ramnifications on the application logic side... -Original Message- Sent: Wednesday, July 24, 2002 7:13 AM To: Multiple recipients of list ORACLE-L If you can take the database down for 1.25 hours. I will hesitate to startup the database with time less then last closing time. Yechiel Adar Mehish - Original Message - To: Multiple recipients of list ORACLE-L [EMAIL PROTECTED] Sent: Monday, July 22, 2002 8:33 PM Hi Guys, I need to put one hour back for my OS(aix) So How will my database(7.3) handle this?? What steps I have to take?? Any light regarding that?? Thanks in advance peter. _ Chat with friends online, try MSN Messenger: http://messenger.msn.com -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Peter R 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: Yechiel Adar 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
RE: MUST read Oracle Architecture - Abrief Intro
In general, I agree with the majority opinion that seems to be saying that Oracle chugs along perfectly happy when the date changes. Time based recovery might have some issues, so I'd run a hot after the change so I could use it as my basis in a restore. The real question in my mind is ... What does the APP do with the dates. If you've got a time finder type app, you may need some data cleanup scripts to make sure calculations done on the stored data come out rightperson clocks in at 7:00 and out at 5:00, that 7 may need to be brought forward to get the overtime off the clock, for instance. Someone else mentioned an accounting issue if invoice 2 goes out before invoice 1. These sorts of issues need to be discussed with power users. It may not be an issue at all. If it IS a serious issue, you need to be thinking about DST (on and off) as well. If it's a big enough issuedo you have ANY maintenance windows? Maybe things could happen then so the data is static and available while fixes associated with the change are also run. Just my $0.02. John P Weatherman Database Administrator Replacements Ltd. -Original Message- Sent: Wednesday, July 24, 2002 12:44 PM To: Multiple recipients of list ORACLE-L Shut the database DOWN for 1.25 hours? Who in the heck can afford THAT! You are *way* off base my friend. If I suggested to my client that they need to shut the database down because of a time change, they would send me out on a rail - and I would deserve it. Bad idea. Tom Mercadante Oracle Certified Professional -Original Message- Sent: Wednesday, July 24, 2002 12:08 PM To: Multiple recipients of list ORACLE-L I think that you will understand it better if you consider 2 scenario's: 1) RMAN backup from time 13:00 is newer then the backup taken at 13:45. 2) You get Enron accounting when the feds discover that invoice number 123 was issued after invoice 124. There are a lot of things, application and / or system, that can go wrong in this situation. To be on the safe side shut the database down for 1.25 hours. Yechiel Adar Mehish - Original Message - To: Multiple recipients of list ORACLE-L [EMAIL PROTECTED] Sent: Wednesday, July 24, 2002 3:38 PM yes , but time based incomplete recovery could create problems if he doesnt take a full backup after the os-time-change . -Original Message- Sent: Wednesday, July 24, 2002 6:39 PM To: Multiple recipients of list ORACLE-L Oracle has no concept wrt. the date time of Operating System for running individually as a product. It just takes the timestamp in certain DML's while updating and inserting the rows having DATE as datatype. Nothing more than this. Oracle works on the mechanism of SCN ie. System Change Number which gets monotonically incremented one by one after every commit takes place. It has nothing to do wrt. the OS time. When the Oracle engine gets started the control file reads the location of datafiles and redo logs and the latest SCN is read and compared with those present in datafiles aand redo logs. If the SCN is not matched menas the database was abnormally shut down and need thread recovery. Smon does this task independently and roll forwards the txn's which were left in the buffer cache and were not pushed back to d.files during checkpoint process. These txn's were committed at the user end. Now the ones which were not committed would be rolled back internally by Oracle b'ground process SMON or Server Process initiated by user process and would rollback the blocks who soever touches them first. A little bit of ARCHITECTURE OF ORACLE .. Bye for now. No problems at the time lagging behind or time forwarding of the OS -Original Message- Sent: Wednesday, July 24, 2002 6:00 PM To: Multiple recipients of list ORACLE-L Oracle will continue to work fine (as it uses SCN numbers for consistency and transaction logging rather than dates). However, if you have any apps which use timestamps in the data, then I'd do some more investigation for the ramnifications on the application logic side... -Original Message- Sent: Wednesday, July 24, 2002 7:13 AM To: Multiple recipients of list ORACLE-L If you can take the database down for 1.25 hours. I will hesitate to startup the database with time less then last closing time. Yechiel Adar Mehish - Original Message - To: Multiple recipients of list ORACLE-L [EMAIL PROTECTED] Sent: Monday, July 22, 2002 8:33 PM Hi Guys, I need to put one hour back for my OS(aix) So How will my database(7.3) handle this?? What steps I have to take?? Any light regarding that?? Thanks in advance peter. _ Chat with friends online, try MSN Messenger: http://messenger.msn.com -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Peter R INET: [EMAIL PROTECTED]
RE: MUST read Oracle Architecture - Abrief Intro
John Weatherman[SMTP:[EMAIL PROTECTED]] wrote: In general, I agree with the majority opinion that seems to be saying that Oracle chugs along perfectly happy when the date changes. Time based recovery might have some issues, so I'd run a hot after the change so I could use it as my basis in a restore. The real question in my mind is ... What does the APP do with the dates. If you've got a time finder type app, you may need some data cleanup scripts to make sure calculations done on the stored data come out rightperson clocks in at 7:00 and out at 5:00, that 7 may need to be brought forward to get the overtime off the clock, for instance. Someone else mentioned an accounting issue if invoice 2 goes out before invoice 1. These sorts of issues need to be discussed with power users. This one in particular is fun to argue with accounts/purchasing people. Even when they have valid date and time data, they start getting really antsy (sp?) when you say the invoice number is just a unique identifier, it has no inherent meaning. I should take the digital camera with me next time so I can take a snap of the cherry-red colour their face goes :-) (Of course, this assumes that the accounting system handles the very date/time problem you're trying to tackle :-) ). Ciao Fuzzy :-) -- Woo Hoo! - H. Simpson -- The contents of this post are my opinions only If swallowed seek medical advice (Apologies for the excess signature) This email message (and attachments) may contain information confidential to TOWER Software. If you are not the intended recipient you cannot use, distribute or copy the message or message attachments. If you are not the intended recipient, please notify the sender by return email immediately and delete all copies of the message and attachments. Opinions, conclusions and other information in this message and attachments that do not relate to the official business of TOWER Software, are not given or endorsed by it. -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Grant Allen 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).
