ADG vs OGG
Shaun Pappas, November 17, 2015 - 8:47 am UTC
Thanks.
Next question:
What is the difference between ADG and GoldenGate ?
When would i use each of them ? What is best practise ?
I have a reporting requirement.
November 18, 2015 - 6:27 am UTC
ADG maintains a physical copy of your primary database (that can be read by queries). You are 100% positive that it and the primary are the same.
Goldengate replicates *changes* from your primary database to a secondary but quite separate copy of your database. This second copy might be a subset, or superset, or simply be divergent from your primary. The advantage is that this secondary database can be read-write...its really a *different* database into which changes are being pushed.
prod DB vs standby DB
Shaun Pappas, November 18, 2015 - 1:38 pm UTC
next question please: what are the risks of running OGG off the standby DB vs the risks of running it off the prod db ?
What the risks of both ?
What is best practise ?
Thank you
Golden Gate limitatons
khal, March 02, 2017 - 4:03 am UTC
Goldengate replicates *changes* from your primary database to a secondary
Yes with a huge limitation .
see 1.6.10 Non-Supported Oracle Data Types
https://docs.oracle.com/goldengate/1212/gg-winux/GIORA/system_requirements.htm#GIORA110 GG does not fully replicated all to target database and this is why is not supported for example EBS and SAP or any major application and you can use a reporting tool on target and not active active database.
===========Supported And Unsupported Oracle Datatype====
1280584.1 Where To Find The List Of Supported And Unsupported Oracle Data Types for GoldenGate ?
Oracle GoldenGate database Schema Profile check script for Oracle DB (Doc ID 1296168.1) Supported datatype inGG
For Golden Gate 11.1
Manual : Oracle GoldenGate Oracle Installation and Setup Guide 11g Release 1 (11.1.1)
Page 10 -> Section "Supported data types"
Page 14 -> Section "Non-supported data types"
GG UNSUPPORTED DDL
====================
alter audit policy
alter database
alter disk group
alter flashback archive
Alter Pluggable Database
alter rollback segment
create audit policy
create bitmapfile
create control file
create database
create disk group
create flashback archive
create pfile
Create Pluggable Database
create restore point
create rollback segment
create schema
create spfile
drop audit policy
drop bitmapfile
drop database
drop disk group
drop flashback archive
Drop Pluggable Database
drop restore point
drop rollback segment
flashback database
flashback table
March 03, 2017 - 2:12 am UTC
Alex, December 06, 2017 - 8:46 pm UTC
Hi all,
We are trying to improve our failover time between data centers. We have a large number of application containers that need to be restarted in order to get them to reconnect to the standby (new primary). The approach we tried to take is to have them already up and connected to the standby so that we could just fail data guard over and be ready to go. We found that it took Oracle quite a while to bring the standby up with connections already in the database. I suppose it's like trying to shutdown immediate a regular database with stuff going on? I was wondering if you had any suggestions to speed this up or a better alternative altogether. Thanks.
Difference between DG and ADG
Milind, December 07, 2017 - 2:34 pm UTC
Also as I understand data Guard doesn't require an extra license, however for Active Data Guard additional license is required.
December 08, 2017 - 6:32 am UTC
Correct.
Whats the difference between Logical Standby and Active Data guard
Manish, August 02, 2019 - 11:20 am UTC
Although both Logical Standby and Active Data guard serve the same purpose. Both are used for reporting.
Only difference i could see Logical is opened in READ/WRITE Mode and Dataguard in Read only with Apply. Synch is performed on both of them.
ADG got licencing cost. So what are the other difference that give preference to ADG
August 05, 2019 - 10:47 am UTC
Although both Logical Standby and Active Data guard serve the same purpose
Not really. And it not a one-versus-the-other discussion.
Logical Standy gives you a production replica that can diverge from the source. The implies some limitations on what you are allowed to have on the source (in terms of data types and options etc) for the benefit of having that divergence. That divergence also has implications in terms of that database being a strict disaster recovery option.
Active Data Guard keeps that sync with the primary much tighter, which puts it closer to a true DR solution, but you sacrifice that divergence that logical standby gives you.
To Connor
J. Laurindo Chiappa, August 06, 2019 - 2:32 pm UTC
Connor, maybe you could comment about Performance in Logical Standby Databases for very active databases: if the primary db run some heavy/complex/slow DML that takes a lot of time AND generates a mountain of undo/redo, the very same DML WILL be executed in the logical standby database, doing so many I/Os, generating redo and undo, consuming resources and taking time there in general...
In the other way, a dataguard done via Physical Standby don´t have this issue, only the redo will be sent and applied and that´s it....
Regards,
Chiappa
August 08, 2019 - 3:28 am UTC
Good point. I should have noted a key difference:
Physical DataGuard
- redo generated on primary, applied directly to standby
Logical DataGuard
- redo generated on primary
- converted to SQL statements
- SQL statements applied to standby