Hi,
I am trying to query a table XYZ (included 22 columns) in SQL server from Oracle via Heterogeneous Gateway, but it has missing a lot of fields in the query result.
Specifically, I ran almost identical SQLs below for same table, one is specified dbo schema and other one is not. In reference, the table name is unique.
ex) SELECT * FROM dbo.XYZ@DB_Link; --> It returned data for only 4 fields. (Total 22 fields exist in SQL server source table)
SELECT * FROM XYZ@DB_Link; --> It returned data for only 14 fields. (Total 22 fields exist in SQL server source table)
Questions :
1. Why both SQLs above return two different result sets in Oracle query and why 2nd query (without specified schema name) has more columns returned?
2. Why both SQLs can't get full columns (total 22) and actually missing lots of fields in Oracle query?
3, I noticed that oracle query couldn't retrieve fields like nvarchar(max) fields in Oracle. Why?
4. In addition, why 1st query has no issue to view field name having over 30 characters but 2nd query doesn't allow over 30 characters of field name.
(We currently have Oracle 12c, which allows 128 characters)