473,324 Members | 2,548 Online
Bytes | Software Development & Data Engineering Community
Post Job

Home Posts Topics Members FAQ

Join Bytes to post your question to a community of 473,324 software developers and data experts.

Rollforward recovery algorithm...

I have asked a similar question before, but am still not very clear on
this......expecting some insights on this one....

Ok, so these are the two pieces of information regarding archived logs
during a rollforward recovery in a recoverable database:

1. OVERFLOWLOGPATH configuration parameter can specify a location for
DB2 to find log files that are needed for rollforward operations.

2. The database configuration file parameter 'userexit' specifies
whether the database manager invokes a user exit program to retrieve
log
files during rollforward recovery of databases.

So, it seems that the algorithm during a rollforward recovery is:

1. Check the active log path directory for the required logs. If logs
are not found here, go to step 2.

2. Check to see if OVERFLOWLOGPATH db. Config. Parm. is specified (or
OVERFLOW LOG PATH parameter is specified in the ROLLFORWARD DATABASE
command).
a. If OVERFLOWLOGPATH is specified, see if the required log files
exist
there. If log files are not present there then check if 'userexit' is
enabled.
i. If 'userexit' is enabled, invoke the userexit to find the location
of the log files. If log found in the location given by userexit,
continue with the rollforward operation else give the 'log not found'
error.

ii. If 'userexit' is diabled, give the 'log not found' error.

b. If OVERFLOWLOGPATH is not specified, check if 'userexit' is
enabled.

i. If 'userexit' is enabled, invoke the userexit to find the location
of the log files. If log found in the location given by userexit,
continue with the rollforward operation else give the 'log not found'
error.
ii. If 'userexit' is diabled, give the 'log not found' error.

So, basically, the sequence is: active log path directory,
OVERFLOWLOGPATH directory and lastly the 'userexit'.

Is my understanding correct or flawed.

TIA
Raquel.
Nov 12 '05 #1
2 2589
The sequence you use at the end of your note is right.
One more point.
The overflow logpath parm. must b specified if you logpath is defined over
raw devices. The logpath will be checked, if log file is not there, the
overflow is checked; if not found againand the exit is used (which in thic
case should always be) then the FILES stored in the archive can ONLY be
retrieved to the overflow logpath as the exit is not able to deal with raw
devices.
HTH, Pierre.
"Raquel" <ra****************@yahoo.com> a écrit dans le message de
news:9a**************************@posting.google.c om...
I have asked a similar question before, but am still not very clear on
this......expecting some insights on this one....

Ok, so these are the two pieces of information regarding archived logs
during a rollforward recovery in a recoverable database:

1. OVERFLOWLOGPATH configuration parameter can specify a location for
DB2 to find log files that are needed for rollforward operations.

2. The database configuration file parameter 'userexit' specifies
whether the database manager invokes a user exit program to retrieve
log
files during rollforward recovery of databases.

So, it seems that the algorithm during a rollforward recovery is:

1. Check the active log path directory for the required logs. If logs
are not found here, go to step 2.

2. Check to see if OVERFLOWLOGPATH db. Config. Parm. is specified (or
OVERFLOW LOG PATH parameter is specified in the ROLLFORWARD DATABASE
command).
a. If OVERFLOWLOGPATH is specified, see if the required log files
exist
there. If log files are not present there then check if 'userexit' is
enabled.
i. If 'userexit' is enabled, invoke the userexit to find the location
of the log files. If log found in the location given by userexit,
continue with the rollforward operation else give the 'log not found'
error.

ii. If 'userexit' is diabled, give the 'log not found' error.

b. If OVERFLOWLOGPATH is not specified, check if 'userexit' is
enabled.

i. If 'userexit' is enabled, invoke the userexit to find the location
of the log files. If log found in the location given by userexit,
continue with the rollforward operation else give the 'log not found'
error.
ii. If 'userexit' is diabled, give the 'log not found' error.

So, basically, the sequence is: active log path directory,
OVERFLOWLOGPATH directory and lastly the 'userexit'.

Is my understanding correct or flawed.

TIA
Raquel.


Nov 12 '05 #2
Thank you so much Pierre for your response. Your responses are always appreciated.

Raquel.

"Pierre Saint-Jacques" <se*****@invalid.net> wrote in message news:<XC********************@wagner.videotron.net> ...
The sequence you use at the end of your note is right.
One more point.
The overflow logpath parm. must b specified if you logpath is defined over
raw devices. The logpath will be checked, if log file is not there, the
overflow is checked; if not found againand the exit is used (which in thic
case should always be) then the FILES stored in the archive can ONLY be
retrieved to the overflow logpath as the exit is not able to deal with raw
devices.
HTH, Pierre.
"Raquel" <ra****************@yahoo.com> a écrit dans le message de
news:9a**************************@posting.google.c om...
I have asked a similar question before, but am still not very clear on
this......expecting some insights on this one....

Ok, so these are the two pieces of information regarding archived logs
during a rollforward recovery in a recoverable database:

1. OVERFLOWLOGPATH configuration parameter can specify a location for
DB2 to find log files that are needed for rollforward operations.

2. The database configuration file parameter 'userexit' specifies
whether the database manager invokes a user exit program to retrieve
log
files during rollforward recovery of databases.

So, it seems that the algorithm during a rollforward recovery is:

1. Check the active log path directory for the required logs. If logs
are not found here, go to step 2.

2. Check to see if OVERFLOWLOGPATH db. Config. Parm. is specified (or
OVERFLOW LOG PATH parameter is specified in the ROLLFORWARD DATABASE
command).
a. If OVERFLOWLOGPATH is specified, see if the required log files
exist
there. If log files are not present there then check if 'userexit' is
enabled.
i. If 'userexit' is enabled, invoke the userexit to find the location
of the log files. If log found in the location given by userexit,
continue with the rollforward operation else give the 'log not found'
error.

ii. If 'userexit' is diabled, give the 'log not found' error.

b. If OVERFLOWLOGPATH is not specified, check if 'userexit' is
enabled.

i. If 'userexit' is enabled, invoke the userexit to find the location
of the log files. If log found in the location given by userexit,
continue with the rollforward operation else give the 'log not found'
error.
ii. If 'userexit' is diabled, give the 'log not found' error.

So, basically, the sequence is: active log path directory,
OVERFLOWLOGPATH directory and lastly the 'userexit'.

Is my understanding correct or flawed.

TIA
Raquel.

Nov 12 '05 #3

This thread has been closed and replies have been disabled. Please start a new discussion.

Similar topics

3
by: Raquel | last post by:
During a ROLLFORWARD recovery, are the log datasets copied from the archive log directory to the active log directory? I know the log datasets are copied from archive log directory to active log...
3
by: Michelle | last post by:
Hi, I'm trying to rollforward my database to end of logs and complete, the first error message i get is - SQL6063N rollforward recovery on database X has stopped on node "0" due to change in log...
2
by: shenanwei | last post by:
DB2 V8.1.5 on Windows. When I execute ROLLFORWARD after a Restore. C:\db2 ROLLFORWARD db sample to END OF LOGS overflow log path(C:\LOGS\) Rollforward Status Input database alias ...
3
by: t2581 | last post by:
Hi , I run restore with rollforward In job in output, last commited transaction time less then backup image time Is it normal ? RESTORE DATABASE PRICE_V8 FROM "E:\BACKUP" TAKEN AT...
3
by: t2581 | last post by:
Hi, we are daily restore db "PRICE" with rollforward from server A into PRICE on server B Usually we restore from backup with timestamp of ~ 02:00 AM and applying logs till 7 AM (30-50...
18
by: darnold | last post by:
I have restored a clients database using a redirected restore. However, it is in a roll forward pending state. When I try to to a roll forward to end of the logs, I get SQL1268N Roll-forward...
3
by: EC | last post by:
We have two DB2 servers are supposed to be a replicate of each other with a database of the same name. I want to do a 'db2 db backup online... include logs' on the first server, and do a 'db2...
1
by: balubkp | last post by:
can u plz tell me the rollforward recovery & rollforward pending state concepts
0
by: shorti | last post by:
We are running DB2 UDB 8.1 fp 14 on AIX using archival logging and online backups. I was running some disaster tests and found my database restore was not restoring to the latest active log. ...
0
by: ryjfgjl | last post by:
ExcelToDatabase: batch import excel into database automatically...
0
by: Vimpel783 | last post by:
Hello! Guys, I found this code on the Internet, but I need to modify it a little. It works well, the problem is this: Data is sent from only one cell, in this case B5, but it is necessary that data...
0
by: jfyes | last post by:
As a hardware engineer, after seeing that CEIWEI recently released a new tool for Modbus RTU Over TCP/UDP filtering and monitoring, I actively went to its official website to take a look. It turned...
1
by: CloudSolutions | last post by:
Introduction: For many beginners and individual users, requiring a credit card and email registration may pose a barrier when starting to use cloud servers. However, some cloud server providers now...
1
by: Defcon1945 | last post by:
I'm trying to learn Python using Pycharm but import shutil doesn't work
1
by: Shællîpôpï 09 | last post by:
If u are using a keypad phone, how do u turn on JavaScript, to access features like WhatsApp, Facebook, Instagram....
0
by: af34tf | last post by:
Hi Guys, I have a domain whose name is BytesLimited.com, and I want to sell it. Does anyone know about platforms that allow me to list my domain in auction for free. Thank you
0
by: Faith0G | last post by:
I am starting a new it consulting business and it's been a while since I setup a new website. Is wordpress still the best web based software for hosting a 5 page website? The webpages will be...
0
isladogs
by: isladogs | last post by:
The next Access Europe User Group meeting will be on Wednesday 3 Apr 2024 starting at 18:00 UK time (6PM UTC+1) and finishing by 19:30 (7.30PM). In this session, we are pleased to welcome former...

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.