Wednesday, March 23, 2011

ADG with ODI and Exadata

Recently I've been taking a class on ODI. It is really a very interesting ELT tool (notice I didn't say ETL). I am planning on using it to take data from my ADG (active data guard) copy of production to another server. Perfect right ? Pull from a read-only copy of an oracle database, to another database. I pick my LKM (load Knowledge Module) of Oracle-oracle. Unfortunately the current knowledge module creates a view on the source. As you can imagine, with ADG, this is impossible. The only way to get ODI working against ADG is to create your own Knowledge Module, so I've been spending my evening creating my very own. I am hoping this can help others who are running into the same issue. First this is a great site explaining HOW to create your very own knowledge module...
This is a great site to find all the syntax you need.

Finally these are the steps I did to make my own knowledge module.

1) copy the oracle to oracle(DBLINK) module
2) Give it a new name like oracle to oracle(ADG)
3) Remove the following steps

- 70 create view/table on source
- 80 Create temp indexes on source
- 150 drop view on source
- 160 Drop temp indexes

4) change drop synonym on target to drop view on target

drop synonym <%=odiRef.getTable("L", "COLL_NAME", "W")%>


drop view <%=odiRef.getTable("L", "COLL_NAME", "W")%>

4) Change the "drop synonym on target" to "drop view on target"

drop synonym <%=odiRef.getTable("L", "COLL_NAME", "W")%>becomes

drop view <%=odiRef.getTable("L", "COLL_NAME", "W")%>

5) Last change. "create synonym on target" becomes "create view on target"

create synonym <%=odiRef.getTable("L", "COLL_NAME", "W")%>
for <%=odiRef.getTable("R", "COLL_NAME", "W")%>


<% if ((odiRef.getOption("ENABLE_EDITION_SUPPORT")).equals("0")) { %>
create or replace view <%=odiRef.getTable("L", "COLL_NAME", "W")%>
<%=odiRef.getColList("", "[CX_COL_NAME]", ",\n\t", "", "")%>
as select <%=odiRef.getPop("DISTINCT_ROWS")%>
<%=odiRef.getColList("", "[COL_NAME]", ",\n\t", "", "")%>
from <%=odiRef.getSrcTablesList("", "[SCHEMA].[TABLE_NAME]@", ", ", "")%><%=odiRef.getInfo("SRC_DSERV_NAME")%>
where (1=1)
<% } else { %>
create table <%=odiRef.getTable("L", "COLL_NAME", "W")%> as
select <%=odiRef.getPop("DISTINCT_ROWS")&%>
<%=odiRef.getColList("", "[COL_NAME]\t[CX_COL_NAME]", ",\n\t", "", "")%>
from <%=odiRef.getSrcTablesList("", "[SCHEMA].[TABLE_NAME]@", ", ", "")%><%=odiRef.getInfo("SRC_DSERV_NAME%>
where (1=1)

As you can see the idea is to remove any updates to the source, and switch the synonym in the target to a view pointing at the source.

And some advice. If you are using the simulation button to test the new Knowledge module, the "getinfo" commands only contain data at runtime.. The simulate will show nothing, and you will only see data when you actually execute (lost about an hour on that one).

Enjoy.. I am posting my actual XML knowledge module here.

The usual disclaimers here.. test well.. I also want to point out that I only changed the Oracle-oracle knowledge module. If you are going from Oracle to Netezza for example, you need to make the appropraite changes to that knowledge module.

I am including another article I found on a knowledge mudule that doesn't create the link..

1 comment:

  1. Great post, Bryan...may I add your blog to my "helpful URLs?" See you in a little while.