To retrieve data after process abended

Question

Hi everyone,
Is there any method of replicating the DDL,DML 's fired after the processes like replicat abended.
Currently i am using : alter replicat rep1 begin now
It seems to work to make processes running again but the i lost the data that was replicated after the process abended.
plz help......
thanks
Saurav

Answer 1

Hi,
1.
My Suggestion is NOT to use BEGIN NOW option with Replicat. This will make your target tables go out of sync and miss some of the DML/DDL as you are altering replciat to process from current time stamp instead of recovery.
GGSCI>alter replicat rep1 begin now
Instead you should always start at seqno 0 and RBA 0 if you are starting fresh or starting Relicat for first time
GGSCI>alter replicat <replicat_name>, Extseqno 0, Extrba 0
GGSCI>start replicat <replicat_name>
OR
if the Replicat has abended earlier and you would like to restart it, you should simply restart it as it will have all the checkpoint information with it and it will automatically start processing data from the recovery checkpoint(trail file).
GGSCI>start replicat <replicat_name>
OR
If you intend to start processing fom a specific trail file then you should use below command
Example:
$cd trail
$ls -ltr
lt000123
lt000124
lt000125
If you are sure that the Replciat processed trail file 123 and you would like to start from trail file seq 124 then try
GGSCI>alter replicat <replicat_name>, Extseqno 124, Extrba 0
GGSCI>start replicat <replicat_name>
OR
If you want to start processing from specific record or start of transaction with in a trail file then you could use LOGDUMP utility to find the RBA and use the same to alter the Replicat.
GGSCI>alter replicat <replicat_name>, Extseqno 124, Extrba 8999934
GGSCI>start replicat <replicat_name>
2.
As you have already lost some of the data and your target DB is already out of sync, I would suggest below method to resync it.
full database export using expdp(Oracle Source to Oracle Target)
1) Enable Minimal Supplemental Logging in Oracle on source
SQLPLUS > alter database add supplemental log data ;
2) Enable Supplemental Logging at Table Level on source
GGSCI> dblogin userid xxxxx password xxxxxx
GGSCI> add trandata <schema>.<tablename>
3) Add Extract, Add Exttrail, Add Pump, Add Rmttrail on source
4) Start Extract, Start Pump on source
5) Create a database directory:
SQLPLUS> create directory dumpdir as '<some directory>' ;
6) Get the current SCN on the source database:
SQLPLUS> select current_scn from v$database ;
28318029
7) Run the export using the flashback SCN you obtained in the previous step. The following example shows running the expdp utility at a Degree Of Parallelism (DOP) of 4. If you have sufficient system resources (CPU,memory and IO) then running at a higher DOP will decrease the amount of time it takes to take the export (up to 4x for a DOP of 4). Note that expdp uses Oracle Database parallel execution settings (e.g.parallel_max_servers) which have to be set appropriately in order to take advantage of parallelism. Other processes running in parallel may be competing for those resources. See the Oracle Documentation for more details.
a.expdp directory=dumpdir full=y parallel=4 dumpfile=ora102_%u.dmp flashback_scn=28318029
Username: sys as sysdba
Password:
Note: The export log needs to be checked for errors.
8) Start an import using impdp to the target database when step 7 is complete.
9) Add and Start Replicat:
GGSCI> add replicat <rep_name>, exttrail ./dirdat/<xx>
GGSCI> start replicat <rep_name>, aftercsn <value returned from step 6>
Hope this information helps.
Thanks & Regards
SK