Did update SQL support joiner?

[aa...@tophold.com]

We have one Main CacheA is partition cache，  another is local cache CacheB,  we 
write back to the main cache periodically from local CacheB .

The Main CacheA object include those fields:

 fieldA,
 fieldB,
 fieldC,
 fieldD
  
 Local cache CacheB
 
 fieldA
 fieldC
 fieldD
 fieldE
 
And update use this SQL:
 
  UPDATE CacheA
  SET (A.fieldC, A.fieldD)=(

B.fieldC,
B.fieldD
  )
  FROM CacheA A, CacheB B
  WHERE A.fieldA = B.fieldA
  AND B.fieldE > 0

  
This SQL have no exception thrown , but the Main cache's fieldC & fieldD seems 
never change. 



Regards
Aaron


Aaron.Kuai