Some queries on Data Guard design

Hi, I have some basic questions around Data Guard design
Q1. Looking at the Oracle instructions for creating a logical standby, it firstly advocates creating a physical standby and then converting it to a logical standby. However I thought a logical standby could have a completely different physical structure from the primary. How can this be the case if a logical standby first starts its life as a physical standby ( where structure needs to be identical ) ?
Q2. Is it normal practice to backup your standby database as well – if so why ?
Q3. Can RMAN backup a Standby Database whilst it is in the mounted state ( rather than open ) ?
Q4. What's the point of Cascaded Redo Apply rather than simply getting the Primary to ship to each Standby ?
I guess you could be trying to reduce node to node latency if some of the standby were quite distant from the primary
Q5. Is it possible to convert a Logical Standby back to a Physical one ?
Q6. What the maximium number of standbys you can have - Oracle suggests 30 but I thought I remember reading somewhere in relation to 11gR2 that this limit has now been increased ?
thanks,
Jim

Hi,
Q5 . Is it possible to convert a Logical Standby back to a Physical one ? --- Yes it is possible .
-- Primary
select switchover_status from v$database;
SWITCHOVER_STATUS
SESSIONS ACTIVE
2) switch operation
-- Primary - starat database switch
alter database commit to switchover to physical standby with session shutdown;
-- see alertlog.
Switchover: Complete - Database shutdown required
Completed: alter database commit to switchover to physical standby with session shutdown
-- database role ve switchover_status
select NAME,OPEN_MODE,DATABASE_ROLE,SWITCHOVER_STATUS,PROTECTION_MODE,PROTECTION_LEVEL from v$database;
NAME      OPEN_MODE            DATABASE_ROLE    SWITCHOVER_STATUS    PROTECTION_MODE      PROTECTION_LEVEL
TESTCRD   READ WRITE           PHYSICAL STANDBY RECOVERY NEEDED      MAXIMUM AVAILABILITY UNPROTECTED
-- Primary
shutdown abort
-- standby - switch to primary
alter database commit to switchover to primary with session shutdown;
-- alert log
Completed: alter database commit to switchover to primary with session shutdown
alter database open
3) Old Primary open
sqlplus / as sysdba
startup nomount
alter database mount standby database
-- database role ve switchover_status
select NAME,OPEN_MODE,DATABASE_ROLE,SWITCHOVER_STATUS,PROTECTION_MODE,PROTECTION_LEVEL from v$database;
NAME      OPEN_MODE            DATABASE_ROLE    SWITCHOVER_STATUS    PROTECTION_MODE      PROTECTION_LEVEL
TESTCRD   READ WRITE           PHYSICAL STANDBY RECOVERY NEEDED      MAXIMUM AVAILABILITY UNPROTECTED
recover managed standby database using current logfile disconnect from session;
4) Old standby
SQL> select NAME,OPEN_MODE,DATABASE_ROLE,SWITCHOVER_STATUS,PROTECTION_MODE,PROTECTION_LEVEL from v$database;
NAME      OPEN_MODE            DATABASE_ROLE    SWITCHOVER_STATUS    PROTECTION_MODE      PROTECTION_LEVEL
AZKKDB    READ WRITE           PRIMARY          TO STANDBY           MAXIMUM PERFORMANCE MAXIMUM PERFORMANCE
Q2 . . Is it normal practice to backup your standby database as well – if so why ?
Hence you only have to backup one of the both (you can decide to only backup the standby though, if you want to remove load on the primary). But if you are confident with the backup of the primary, there is no need for backing up the standby. (Since you can recreate the standby with the backup from primary).
Please see link : http://blog.dbvisit.com/rman-backups-on-your-standby-database-yes-it-is-easy/
Thank you

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Problem with data guard Creating a Physical Standby Database turorial

There is a tutorial of Creating a data guard Physical Standby Database:
http://www.oracle.com/technology/obe/11gr1_db/ha/dataguard/physstby/physstdby.htm
I tried to install it on two servers. One for primary database second for physical standby.
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'Kindly do the needful' and create the service prior to starting the instance in nomount mode
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IIRC there is an option in database control (in the maintenance part) which automates everything.
Sybrand Bakker
Senior Oracle DBA
Experts: those who do read documentation

Database issues after starting data guard

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WARNING: Broker name (mytest) and target name (mydb) do not match.
WARNING: The broker name will be renamed to match the target name.
Skipping verification of fast-start failover static services check.
Data Protection Settings:
Protection mode : Maximum Performance
Redo Transport Mode settings:
pnjpcep1: ASYNC
cnjpcep1: ASYNC
Checking standby redo log files.....not checked due to broker name mismatch. Run verify again.
Checking Data Guard status
mydb : Normal
my11g : Normal
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Ref
Cloud Control: "Data Guard Internal Error" raised on Data Guard Performance Page (Doc ID 1484028.1)
Regards,
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Need some low level help/info on Grid Control / Data Guard

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This is not an issue, just wanted to know how this can be done.
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Clarification on Data Guard(Physical Standyb db)

Hi guys,
I have been trying to setup up Data Guard with a physical standby database for the past few weeks and I think I have managed to setup it up and also perform a switchover. I have been reading a lot of websites and even Oracle Docs for this.
However I need clarification on the setup and whether or not it is working as expected.
My environment is Windows 32bit (Windows 2003)
Oracle 10.2.0.2 (Client/Server)
2 Physical machines
Here is what I have done.
Machine 1
1. Create a primary database using standard DBCA, hence the Oracle service(oradgp) and password file are also created along with the listener service.
2. Modify the pfile to include the following:-
oradgp.__db_cache_size=436207616
oradgp.__java_pool_size=4194304
oradgp.__large_pool_size=4194304
oradgp.__shared_pool_size=159383552
oradgp.__streams_pool_size=0
*.audit_file_dest='M:\oracle\product\10.2.0\admin\oradgp\adump'
*.background_dump_dest='M:\oracle\product\10.2.0\admin\oradgp\bdump'
*.compatible='10.2.0.3.0'
*.control_files='M:\oracle\product\10.2.0\oradata\oradgp\control01.ctl','M:\oracle\product\10.2.0\oradata\oradgp\control02.ctl','M:\oracle\product\10.2.0\oradata\oradgp\control03.ctl'
*.core_dump_dest='M:\oracle\product\10.2.0\admin\oradgp\cdump'
*.db_block_size=8192
*.db_domain=''
*.db_file_multiblock_read_count=16
*.db_name='oradgp'
*.db_recovery_file_dest='M:\oracle\product\10.2.0\flash_recovery_area'
*.db_recovery_file_dest_size=21474836480
*.fal_client='oradgp'
*.fal_server='oradgs'
*.job_queue_processes=10
*.log_archive_dest_1='LOCATION=E:\ArchLogs VALID_FOR=(ALL_LOGFILES,ALL_ROLES) DB_UNIQUE_NAME=oradgp'
*.log_archive_dest_2='SERVICE=oradgs LGWR ASYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=oradgs'
*.log_archive_format='ARC%S_%R.%T'
*.log_archive_max_processes=30
*.nls_territory='IRELAND'
*.open_cursors=300
*.pga_aggregate_target=203423744
*.processes=150
*.remote_login_passwordfile='EXCLUSIVE'
*.sga_target=612368384
*.standby_file_management='auto'
*.undo_management='AUTO'
*.undo_tablespace='UNDOTBS1'
*.user_dump_dest='M:\oracle\product\10.2.0\admin\oradgp\udump'
*.service_names=oradgp
The locations on the harddisk are all available and archived redo are created (e:\archlogs)
3. I then add the necessary (4) standby logs on primary.
4. To replicate the db on the machine 2(standby db), I did an RMAN backup as:-
RMAN> run
{allocate channel d1 type disk format='M:\DGBackup\stby_%U.bak';
backup database plus archivelog delete input;
5. I then copied over the standby~.bak files created from machine1 to machine2 to the same directory (M:\DBBackup) since I maintained the directory structure exactly the same between the 2 machines.
6. Then created a standby controlfile. (At this time the db was in open/write mode).
7. I then copied this standby ctl file to machine2 under the same directory structure (M:\oracle\product\10.2.0\oradata\oradgp) and replicated the same ctl file into 3 different files such as: CONTROL01.CTL, CONTROL02.CTL & CONTROL03.CTL
Machine2
8. I created an Oracle service called the same as primary (oradgp).
9. Created a listener also.
9. Set the Oracle Home & SID to the same name as primary (oradgp) <<<-- I am not sure about the sid one.
10. I then copied over the pfile from the primary to standby and created an spfile with this one.
It looks like this:-
oradgp.__db_cache_size=436207616
oradgp.__java_pool_size=4194304
oradgp.__large_pool_size=4194304
oradgp.__shared_pool_size=159383552
oradgp.__streams_pool_size=0
*.audit_file_dest='M:\oracle\product\10.2.0\admin\oradgp\adump'
*.background_dump_dest='M:\oracle\product\10.2.0\admin\oradgp\bdump'
*.compatible='10.2.0.3.0'
*.control_files='M:\oracle\product\10.2.0\oradata\oradgp\control01.ctl','M:\oracle\product\10.2.0\oradata\oradgp\control02.ctl','M:\oracle\product\10.2.0\oradata\oradgp\control03.ctl'
*.core_dump_dest='M:\oracle\product\10.2.0\admin\oradgp\cdump'
*.db_block_size=8192
*.db_domain=''
*.db_file_multiblock_read_count=16
*.db_name='oradgp'
*.db_recovery_file_dest='M:\oracle\product\10.2.0\flash_recovery_area'
*.db_recovery_file_dest_size=21474836480
*.fal_client='oradgs'
*.fal_server='oradgp'
*.job_queue_processes=10
*.log_archive_dest_1='LOCATION=E:\ArchLogs VALID_FOR=(ALL_LOGFILES,ALL_ROLES) DB_UNIQUE_NAME=oradgs'
*.log_archive_dest_2='SERVICE=oradgp LGWR ASYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=oradgp'
*.log_archive_format='ARC%S_%R.%T'
*.log_archive_max_processes=30
*.nls_territory='IRELAND'
*.open_cursors=300
*.pga_aggregate_target=203423744
*.processes=150
*.remote_login_passwordfile='EXCLUSIVE'
*.sga_target=612368384
*.standby_file_management='auto'
*.undo_management='AUTO'
*.undo_tablespace='UNDOTBS1'
*.user_dump_dest='M:\oracle\product\10.2.0\admin\oradgp\udump'
*.service_names=oradgs
log_file_name_convert='junk','junk'
11. User RMAN to restore the db as:-
RMAN> startup mount;
RMAN> restore database;
Then RMAN created the datafiles.
12. I then added the same number (4) of standby redo logs to machine2.
13. Also added a tempfile though the temp tablespace was created per the restore via RMAN, I think the actual file (temp01.dbf) didn't get created, so I manually created the tempfile.
14. Ensuring the listener and Oracle service were running and that the database on machine2 was in MOUNT mode, I then started the redo apply using:-
SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT FROM SESSION;
It seems to have started the redo apply as I've checked the alert log and noticed that the sequence# was all "YES" for applied.
****However I noticed that in the alert log the standby was complaining about the online REDO log not being present****
So copied over the REDO logs from the primary machine and placed them in the same directory structure of the standby.
########Q1. I understand that the standby database does not need online REDO Logs but why is it reporting in the alert log then??########
I wanted to enable realtime apply so, I cancelled the recover by :-
SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE CANCEL;
and issued:-
SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT LOGFILE DISCONNECT;
This too was successful and I noticed that the recovery mode is set to MANAGED REAL TIME APPLY.
Checked this via the primary database also and it too reported that the DEST_2 is in MANAGED REAL TIME APPLY.
Also performed a log swith on primary and it got transported to the standby and was applied (YES).
Also ensured that there are no gaps via some queries where no rows were returned.
15. I now wanted to perform a switchover, hence issued:-
Primary_SQL> ALTER DATABASE COMMIT TO SWITCHOVER TO PHYSICAL STANDBY WITH SESSION SHUTDOWN;
All the archivers stopped as expected.
16. Now on machine2:
Stdby_SQL> ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY;
17. On machine1:
Primary_Now_Standby_SQL>SHUTDOWN IMMEDIATE;
Primary_Now_Standby_SQL>STARTUP MOUNT;
Primary_Now_Standby_SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT LOGFILE DISCONNECT;
17. On machine2:
Stdby_Now_Primary_SQL>ALTER DATABASE OPEN;
Checked by switching the logfile on the new primary and ensured that the standby received this logfile and was applied (YES).
However, here are my questions for clarifications:-
Q1. There is a question about ONLINE REDO LOGS within "#" characters.
Q2. Do you see me doing anything wrong in regards to naming the directory structures? Should I have renamed the dbname directory in the Oracle Home to oradgs rather than oradgp?
Q3. When I enabled real time apply does that mean, that I am not in 'MANAGED' mode anymore? Is there an un-managed mode also?
Q4. After the switchover, I have noticed that the MRP0 process is "APPLYING LOG" status to a sequence# which is not even the latest sequence# as per v$archived_log. By this I mean:-
SQL> SELECT PROCESS, STATUS, THREAD#, SEQUENCE#, BLOCK#, BLOCKS,FROM V$MANAGED_STANDBY;
MRP0 APPLYING_LOG 1 47 452 1024000
but :
SQL> select max(sequence#) from v$archived_log;
46
Why is that? Also I have noticed that one of the sequence#s is NOT applied but the later ones are:-
SQL> SELECT SEQUENCE#,APPLIED FROM V$ARCHIVED_LOG ORDER BY SEQUENCE#;
42 NO
43 YES
44 YES
45 YES
46 YES
What could be the possible reasons why sequence# 42 didn't get applied but the others did?
After reading several documents I am confused at this stage because I have read that you can setup standby databases using 'standby' logs but is there another method without using standby logs?
Q5. The log switch isn't happening automatically on the primary database where I could see the whole process happening on it own, such as generation of a new logfile, that being transported to the standby and then being applied on the standby.
Could this be due to inactivity on the primary database as I am not doing anything on it?
Sorry if I have missed out something guys but I tried to put in as much detail as I remember...
Thank you very much in advance.
Regards,
Bharath
Edited by: Bharath3 on Jan 22, 2010 2:13 AM

Parameters:
Missing on the Primary:
DB_UNIQUE_NAME=oradgp
LOG_ARCHIVE_CONFIG=DG_CONFIG=(oradgp, oradgs)
Missing on the Standby:
DB_UNIQUE_NAME=oradgs
LOG_ARCHIVE_CONFIG=DG_CONFIG=(oradgp, oradgs)
You said: Also added a tempfile though the temp tablespace was created per the restore via RMAN, I think the actual file (temp01.dbf) didn't get created, so I manually created the tempfile.
RMAN should have also added the temp file. Note that as of 11g RMAN duplicate for standby will also add the standby redo log files at the standby if they already existed on the Primary when you took the backup.
You said: ****However I noticed that in the alert log the standby was complaining about the online REDO log not being present****
That is just the weird error that the RDBMS returns when the database tries to find the online redo log files. You see that at the start of the MRP because it tries to open them and if it gets the error it will manually create them based on their file definition in the controlfile combined with LOG_FILE_NAME_CONVERT if they are in a different place from the Primary.
Your questions (Q1 answered above):
You said: Q2. Do you see me doing anything wrong in regards to naming the directory structures? Should I have renamed the dbname directory in the Oracle Home to oradgs rather than oradgp?
Up to you. Not a requirement.
You said: Q3. When I enabled real time apply does that mean, that I am not in 'MANAGED' mode anymore? Is there an un-managed mode also?
You are always in MANAGED mode when you use the RECOVER MANAGED STANDBY DATABASE command. If you use manual recovery "RECOVER STANDBY DATABASE" (NOT RECOMMENDED EVER ON A STANDBY DATABASE) then you are effectively in 'non-managed' mode although we do not call it that.
You said: Q4. After the switchover, I have noticed that the MRP0 process is "APPLYING LOG" status to a sequence# which is not even the latest sequence# as per v$archived_log. By this I mean:-
Log 46 (in your example) is the last FULL and ARCHIVED log hence that is the latest one to show up in V$ARCHIVED_LOG as that is a list of fully archived log files. Sequence 47 is the one that is current in the Primary online redo log and also current in the standby's standby redo log and as you are using real time apply that is the one it is applying.
You said: What could be the possible reasons why sequence# 42 didn't get applied but the others did?
42 was probably a gap. Select the FAL columns as well and it will proably say 'YES' for FAL. We do not update the Primary's controlfile everytime we resolve a gap. Try the same command on the standby and you will see that 42 was indeed applied. Redo can never be applied out of order so the max(sequence#) from v$archived_log where applied = 'YES' will tell you that every sequence before that number has to have been applied.
You said: After reading several documents I am confused at this stage because I have read that you can setup standby databases using 'standby' logs but is there another method without using standby logs?
Yes, If you do not have standby redo log files on the standby then we write directly to an archive log. Which means potential large data loss at failover and no real time apply. That was the old 9i method for ARCH. Don't do that. Always have standby redo logs (SRL)
You said: Q5. The log switch isn't happening automatically on the primary database where I could see the whole process happening on it own, such as generation of a new logfile, that being transported to the standby and then being applied on the standby.
Could this be due to inactivity on the primary database as I am not doing anything on it?
Log switches on the Primary happen when the current log gets full, a log switch has not happened for the number of seconds you specified in the ARCHIVE_LAG_TARGET parameter or you say ALTER SYSTEM SWITCH LOGFILE (or the other methods for switching log files. The heartbeat redo will eventually fill up an online log file but it is about 13 bytes so you do the math on how long that would take :^)
You are shipping redo with ASYNC so we send the redo as it is commited, there is no wait for the log switch. And we are in real time apply so there is no wait for the log switch to apply that redo. In theroy you could create an online log file large enough to hold an entire day's worth of redo and never switch for the whole day and the standby would still be caught up with the primary.

I have some queries usage of RAID 1 on OSX

Hi there
I apologise for the length of this question, but there's quite a bit of relevant data. I work in a small typesetting company (<10 employees) and since a HDD failed on an old G4 iMac that we used as a data archive we have learnt that without our data we are nothing. I have now been asked to implement a more reliable back up/recovery system (with minimum downtime) that increases the 'safety' of our customer's data. Rebuilding the archive took days to sort out and because the archive was constantly accessed by our production macs and a couple of PC as well, it hit us hard.
We are looking into turning an old G5 Powermac (1.8Gz single processor 2.5Gb RAM) into a RAID 1 (mirrored) system with 2 x 1TB SATA drives using Disk Utility. We would have this to protect against one HD failing and losing customers' data. I understand that this is not a back up system, just something that would protect customer's data should a drive critically fail. I have some queries regarding how this works though.
1) How much (if any) maintenance is required on a RAID system? None of use are IT specialists - just typesetters with a bit of technical knowledge.
2) Is a mirrored RAID system reliable, considering multiple people are reading/writing to the machine throughout the day?
3) Do RAID 1 systems handle being accessed by different OSs (WinXP, Win7, OSX 10.4–10.6) well?
4) Am I right in thinking that OSX would see the two drives as separate volumes?
5) Should one drive fail and need to be 'rebuilt' via Disk Utility, can users still access the one working HD, or do you need to replace the failed HD and rebuild before anyone can access the data again?
6) Considering Question 4 above, do we need to have a 3rd 'spare' 1TB Drive just in case?
7) We are looking into a two-week backup system, backing up all the customers data on a daily basis, with the previous week's disk being stored off-site. We were initially looking into either Carbon Copy Cloner or RSync the copy data to external HDDs. How would you rate Time Machine against these products, and does anyone have any experience using these solutions with RAIDed Macs?
8) Is there any 'downside' to RAID 1 systems?
I know this is a lot of questions, but I really don't want to start down this route unless I understand it better first.
Many thanks in advance for your contributions!

Mac_fool wrote:
Thanks for your reply!
So, in order to have a RAID visible and accessible by multiple OSs, and to eliminate downtime during rebuilds, a hardware RAID would be necessary.
Well, not quite. When you create a RAID in Disk Utility, the volume only exists as a MacOS X file system. Your Mac can share that volume to any other machines or operating systems.
What I mean by a hardware RAID is some box whose output port is eSATA or USB or some other non-network storage port. On such a device, the logic to create the file system is inside the box. Any machine that is connected to it would see only a single disk. You would still have to ensure that different operating systems could understand whatever file system you were using (HFS+, FAT, NTFS, etc), but that is the same as if you had a non-RAID external drive.
I have one of those. It is an older FireWire 800 drive that has two 300 GB disks inside. To any machine I connect that to, it appears as a single 600 GB drive. This particular device isn't designed for mirroring, however. If it were, it would only show itself as a 300 GB hard drive and I would have the capability to easily swap out the internal mechanisms when they fail.
By 'hardware RAID', do you mean inserting a RAID controller card inside the G5, or a separate storage device, such as a RAIDed NAS-type-thing? Would an ethernet-connected NAS be slower to access than a G5 with internal SATA? Am I right in thinking that those RAID-ready NAS devices cannot be partitioned at all?
I qualified the above to explicity avoid NAS devices just to simplify things.
I'm not familiar with RAID controller cards. My guess is that they are just a cheaper alternative to an external RAID device. It would allow you to plug your own hard drives into the controller card and create the RAID. They would certainly provide higher performance that if the operating system were handling the details.
If you want to have a RAID for data reliablity, you really need an external, self-contained device that has a standard hardware storage port you could plug into any machine. It would look and act just like any other external hard drive. But if a drive failed, a light would flash on the box and you could just pull out the failed hard drive and replace it with a new one. You wouldn't even need to power anything down.
For both RAID controller cards and stand-alone boxes, you may or may not need additional software to partition and format the drive. It depends on the model and manufacturer.
Such a device could also be NAS. In this case, it would have an ethernet interface instead (or in addition). The difference is that such an interface would almost always be slower than a true storage interface like Firewire or USB. Plus, you would usually have to let the box itself handle its partitioning and formatting. Since it is designed to be a networked drive, you don't need another machine to be the server. It is its own server. This is useful in those cases where you don't want/need a dedicated server. The downside is that it probably runs some lowest-common denominator Windows networking for maximum compatibility. Foreign, networked filesystems are always going to be more flaky. Some software may not work. Some OS upgrade may give you hassles.
To be honest, I'm no expert on RAIDs. In such situations, I usually just defer to people I know are experts. So, just buy the amount one of these: (http://eshop.macsales.com/shop/hard-drives/RAID/Desktop/), plug it in, and go. I suggest RAID 5.

What are the pros and cons using Active Data Guard vs Data Guard?

My understanding is that Active Data Guard is an additional database option for Oracle 11gR2 Enterprise Edition. I need to know the pros and cons using Active Data Guard vs Data Guard in order to decide whether to get pay extra for the Active Data Guard.
Thanks for any help.

Hemant K Chitale wrote:
Before jumping in to Active Data Guard, one needs to evaluate :
a. Is there really a need to run queries on the Standby ? The Standby could / should be at a remote site so queries are "across the network". Depending on the nature of the queries and the volume of output, the "performance" of the queries may not seem to be the same.
b. If the database is not in Maximum Protection mode, the data "seen" at the standby may not be in "real-time" synch
c. Not all applications are truely read-only when querying. Some applications use "jobs" that write to tables when querying. Such would not work with Active DataGuard. (example : EBusiness Suite). There are very complicated ways of handling this -- and one needs to consider if the complications can be introduced and supported.
Over the network accessing standby read only is really not an good idea, I think no one will compare performance with primary and standby,
But some of them they want to validate data which are very critical, as it is matching with primary or not, Its an added advantage with ACTIVE DATAGUARD
Prior to that until unless stop MRP, open database and then we need to validate, So there is an interruption of recovery, I can say its also an advantage where there is no interruption of recovery.

Data Guard Configuration Issue / ORA-16047

So last night I decided to setup a test Physical Standby database. I had everything working correctly and when I started playing around with the Data Guard Broker I started having some problems. Now I can't get the logs to ship from the primary to the standby.
Version: Primary and Standby
BANNER
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production
PL/SQL Release 11.2.0.1.0 - Production
CORE    11.2.0.1.0    Production
TNS for Linux: Version 11.2.0.1.0 - Production
NLSRTL Version 11.2.0.1.0 - Production
OS: Primary and Standby
[oracle@dgdb0 trace]$ uname -a
Linux dgdb0.localdomain 2.6.32-100.28.5.el6.x86_64 #1 SMP Wed Feb 2 18:40:23 EST 2011 x86_64 x86_64 x86_64 GNU/LinuxI first noticed a problem with a large gap in sequence numbers.
Standby
SQL> SELECT sequence#, applied from v$archived_log order by sequence#;
SEQUENCE# APPLIED
     8 YES
     9 YES
    10 YES
    11 YES
    12 YES
    13 YES
    14 YES
7 rows selected.
Primary
SQL> archive log list;
Database log mode           Archive Mode
Automatic archival           Enabled
Archive destination           USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence     37
Next log sequence to archive   39
Current log sequence           39Here is some of the configuration information on the primary:
SQL> show parameter db_name
NAME                     TYPE     VALUE
db_name                  string     dgdb0
SQL> show parameter db_unique_name
NAME                     TYPE     VALUE
db_unique_name                 string     dgdb0
SQL> show parameter log_archive_config
NAME                     TYPE     VALUE
log_archive_config             string     dg_config=(dgdb0,dgdb1)
SQL> show parameter log_archive_dest_2
NAME                     TYPE     VALUE
log_archive_dest_2             string     service=dgdb1 async valid_for=
                         (online_logfile,primary_role)
                         db_unique_name=dgdb1Standby parameters
SQL> show parameter db_name
NAME                     TYPE     VALUE
db_name                  string     dgdb0
SQL> show parameter db_unique_name
NAME                     TYPE     VALUE
db_unique_name                 string     dgdb1So I proceeded to run this query:
SQL> SELECT error from v$archive_dest WHERE dest_name='LOG_ARCHIVE_DEST_2';
ERROR
ORA-16047: DGID mismatch between destination setting and target
databaseThe error description is:
Cause:       The DB_UNIQUE_NAME specified for the destination does not match the DB_UNIQUE_NAME at the destination.
Action:     Make sure the DB_UNIQUE_NAME specified in the LOG_ARCHIVE_DEST_n parameter defined for the destination matches the DB_UNIQUE_NAME parameter defined at the destination.As you can see from above the DB_UNIQUE_NAME in the LOG_ARCHIVE_DEST_2 parameter matches that of the standby database.
Also DG_BROKER_START is set to false on both the primary and standby databases.
Finally, I've removed all the drc* files from the $ORACLE_HOME/dbs directories on both the primary and standby servers to ensure the broker is not configured.
Where did I go wrong? How can I get the standby caught up and working correctly again?
I apologized if I missed anything. I'm relatively new to standby databases.

Centinul;
I have noticed a couple things
1. If you are running the query below from the standby you will probably always get the results you posted
SELECT sequence#, applied from v$archived_log order by sequence#;
What I do if run this from the primary and I add the "DEST_ID" column to the query.
2. You might have better luck finding GAPS using these queries:
select max(sequence#) from v$archived_log where applied='YES';
select process,status from v$managed_standby;
SELECT * FROM V$ARCHIVE_GAP;
3. You are mixing SQL results with Data Broker, that can bite you. Not sure where you went wrong but I would create PFILE versions at both ends before trying to Data Broker. The you can review each setting and avoid issues before adding Data Broker. Data Broker will take control and you may even find it adds entries to your parameter file.
The ORA-16047 is probably database parameter related and this should at least help answer the question. For example you might be missing log_archive_config on the Standby or soething. Comparing the two PFILE's should narrow this down
I checked my Data Broker notes but did not find an ORA-16047, I managed ORA-01031, ORA-16675, ORA-12514, and ORA-16608.
For me I decided it was a good idea to run Data Guard without Data Broker at first until I got the feel of it using SQL.
Last of all if you have not already consider buying Larry Carpenter's "Oracle Data Guard 11g Handbook" In my humble opinion its worth every penny and more.
Best Regards
mseberg

Need to create some queries.

Hi,
I am having some issues with creating some queries with respect to some information that is needed.
1) How can i get the list of tables from my schema that have not been used for some time (for e.g for the past 2 months no dml activity has happnd)?
2) How can i get the information of those users in a instance who have direct access to the tables in my schema.?
Thanks,
Shilpesh

SHILPFID wrote:
Hi,
Thanks for that
But i would like to know one more thing.
DDL_TIME will show only any ddl statement issued against that.
What if we are still accessing the tables using select statements ??Well a select statement isn't, strictly speaking, even a DML statement as it is not modifying the data.
There is no automatic recording of time when DML or select statements are executed against tables. With DML you can choose to record that information yourself through your own table design and code. If you have control over the application front end you can record when queries are made, but you can't automatically record when someone queries a table just using a select statement directly on the database (at least not easily)
You can also delve into the archive logs to find DML times but they are not guaranteed to be held for as long as you will require and certainly won't be there two months later.
Essentially, you can't determine information that you haven't chosen to store.

ACLs in a Failsafe/data guard environment

Hi,
We have recently upgraded to Oracle Enterprise Edition 11.2.0.3
We had a slight issue with a few batch processes which sent success emails - we hadn't configured ACL permissions (We knew about it, and was on the log, but somehow got missed). All set up fine now in our test environment, but got a couple of queries before I set up in production.
Had a look in the documentation and tried searching
The ACLs I believe are managed as an XML file, on the database server, correct?
If so, how do we manage this on both a clustered, and a data guard environment? Or in the case of a database restore? Is the ACL file automagically regenerated out of some database metadata? Or do we need to recreate in each environment?
Any ideas?
Cheers,
Carl

Hi,
there is two ACL(Access Control List) one at Db level ans one is used at UNIX command for file permission , as you mentioned you have permission issue in batch execution.
so you can check below link
http://www.dartmouth.edu/~rc/help/faq/permissions.html
i am not sure which ACL you required.

Standby DB vs Data Guard

Hi all,
Is STANDBY DB the same as DATAGUARD? or there are big differences and enhancement made.
Thanks a lot

Hello;
To Data Guard is a true Standby database because it is designed for switchover and failover. I like to think of a Primary and Standby database as one database in different modes. There are other methods of Standby available but they don't provide the RMAN, DBMS_SCHEDULER and Active Data Guard ( Reader ) features or don't provide them as cleanly.
For example a month ago at my shop we had some power work in the main server room. We switched everything to the Standby and disabled the second archive location until the work was complete and then enabled it, let the archive catch up and switched back. We were down a few minutes instead of the whole weekend.
To me Data Guard has made other Standby methods obsolete, its an outstanding product for high availability.
http://www.oracle.com/us/products/database/options/active-data-guard/index.html
There are a few third party products out there, but why would you put your data and recovery in anybody's hands buts Oracle? That sounds like too many cooks to me.
Best Regards
mseberg

Data Query Design help

Hi,
Current I developing a component to query content on the basis of Audience and permission and displaying it on a portal.
We currently have a single oracle database which stores portal content . Because of lack of failover database,temporarily we are thinking of coping the display content to a local XML file and parse the file as per user criteria.The amount of content is not huge and a XML file generated out of oracle is not more than 150 kb.
To read the datasource we have implemented a factory and SAX XML parser which creates data objects and caches it to avoid multiple file reads.
Now I would like to build a object query mechanism around this which is independent of datasource. For example today it queries Cached data objects but later time it will be a SQL builder.
Please comment and give directions
- Santosh

The first question you have to ask yourself is if the object query mechanism that you are trying to build is going to be specific or general. What I mean by that is whether the methods exposed by the object query mechanism is going to be specific to the application that you are working on or applicable generally.
I would recommend that you go application specific as the general case rapidly becomes extremely complex.
If you go application specific, the first task is to design an interface that specifies the query methods that your application will call. I.e. you are setting out the contract that any data store must fulfill in order to service your application.
Once you have this interface, you then need to write classes to implement it for each type of data store that you wish to support.
Finally you need to abstract the decision of which implementation of your interface to use away from the rest of your code. The classic solution is to use the factory pattern: http://builder.com.com/5100-6386-1045719.html
The code in the factory class decides which implementation of the interface to return, usually dependent on a system property or some other runtime variable.
The rest of your application just uses the concrete instance of the interface returned by the factory to access the data whether from the database or the XML objects.

Data Guard x License

Does anyone know that if I by a license of Oracle Enterprise 10g, I would have to pay anything else to use the Data Guard? It appears as optional for Enterprise in the site that describes each database edition features.
Thanks

As with all licensing questions, you really need to address this to your Oracle sales representative. The answers may well depend on things like the country you're in, your organization's relationship with Oracle, other Oracle purchases you're making, your negotiating skills, and how close your salesperson is to the end of the quarter... If there is a question in the future about whether you're licensing is adequate, relying on the advice of some guy on the internet is not going to cut it.
In general, DataGuard is included in the enterprise edition license. Active Data Guard is an extra cost option in 11g that allows, among other things, your physical standby database to be open for queries.
Generally, you have to have appropriate licenses for the standby database just as you would for the primary. That's one of the things, though, that you may well be able to negotiate when you talk with your sales rep.
Justin

Some queries on Data Guard design

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