Joins? with Linked Server Tables

Posted on 2003-04-01
Medium Priority
Last Modified: 2008-03-03
I am moving transactional data from our ERP (SAP) database to SQL Server (2K)for reporting purposes.  The idea is to keep the reporting load off the transactional system.  I am tring to keep the master data in SAP so I don't have to replicate all tables, just the big ones). I have set up a Linked server to the Oracel data.

I have a SQL Server (2K) table "custhist" with columns "custno" and "totalsales".

I have a linked server (Oracle/SAP) on the same server with table "custmaster" with columns "custno" and "custname" index on custno.

What is the best performing syntax to return all records from custhist for custno = "123" containing columns custno, custname and totalsales ?

Question by:sperry4
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Expert Comment

ID: 8247452
I worked with other linnked systems to SQL Server, but not Oracle.

You could do a pass-through query as:
SELECT * FROM OpenQuery(LinkedOracleServer, 'SELECT blah, blah')

Or, you could query it on SQL Server:
SELECT * FROM OracleServer.Database.Table

The syntax might have to be messed with.

You could also look into Microsoft Analysis Services if you did want to move some of the data over in the future for data mining.  It takes a bit of time to capture, massage and save the data, but the response time for browsing cubes and the like is almost instantaneous in some situations.

Author Comment

ID: 8247582
looking for the exact syntax of the select statement that would join the SQL server table data to the linked server table data.

LVL 34

Accepted Solution

arbert earned 400 total points
ID: 8249487
Like this--SQL Usually whines on 3part database names, so make sure you put a table alias on your linked oracle database in the from statement:

select * from custhist as SQLTable
inner join OracleServer.Database.Table as OracleTable
on  sqltable.custno=oracletable.custno
 and sqltable.totalsales=oracletable.totsales


Author Comment

ID: 8255887
Sorry if I'm turning this into a new question but I believe the example query given will run slow (with out using index?).

I believe this to be true as when I run Query 1 below, it takes minutes versus the seconds Query 2 takes.  There is an ORACLE index on MANDT+VRGAR+RBLEN.

Is there a way to use OPENQUERY() in the example query given by arbert on 4/1 ?

Query 1
Select * from SAPLINKED..SAPR3.CE1MEDA AS X where X.MANDT='100' and X.VRGAR='F' and X.RBELN = '1014580858'

Query 2
Select * From OPENQUERY(SAPLINKED, "SELECT * from SAPR3.CE1MEDA where SAPR3.CE1MEDA.MANDT='100' and SAPR3.CE1MEDA.VRGAR='F' and SAPR3.CE1MEDA.RBELN = '1014580858'")

LVL 13

Expert Comment

ID: 8256638
Query 2 is run at server side, but there are some changes in SP3.

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