Performance Problem: Synonym in Schema Referencing Synonym in Diff Schema

Question

Does anyone have any experience using a synonym in one schema that references another synonym in another schema? I found that if I do it this way, the performance drops considerably depending upon the SQL. It runs slow and in some cases I get Oracle errors (i.e. Invalid ROWID). If I change my synonym to reference the actual table in the other schema, it don't get the same degradation in performance.
I'm curious if anyone has experienced the same problem and what options might be available to improve the situation. I lose the "semantic" layer by doing this - having to always reference the physical table instead of the synonym in the other schema.
Thanks for any input or comments you might have.
Sabert

Answer 1

Only 2 schemas. Schema A has a table T1 with a public synonym S1. I am running sql against Schema B, however I have a private synonym S2 in this schema (B) that references synonym S1 in Schema A. Because I am using a synonym to reference another synonym in another schema I'm having performance issues. I tried a test and changed the S2 synonym in schema B to point to the table T1 instead of S1 in schema A and it performed much better. Just want to understand what I'm seeing here. This example might help:
Schema A:
"CREATE SYNONYM S1 FOR T1"
Schema B (I'm running my sql against this schema, but my synonym points to table in schema A):
"CREATE SYNONYM S2 FOR A.S1"
"INSERT INTO XXX SELECT * FROM S2"
I had performance issues with this synonym to synonym, so I changed it to synonym to table:
"CREATE SYNONYM S2 FOR A.T1"
Again, with the change in reference from a synonym to the actual table, things seem to work better. Hope this makes sense.
Thanks for your help.