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Solution 1: SQL Subquery
Thanks to user2015502 for this very smart solution in StackOverflow
-- General SELECT (select <Blob-Column> from <Remote-Table>@<DB-Link> where ...) AS blob_column FROM DUAL;
Example
SELECT ( select BLOB_COLUMN from SAMPLE_TABLE_WITH_BLOB@REMOTE_SERVER b where b.ID = a.ID ) AS BLOB_COLUMN FROM LOCAL_TABLE a;
Solution 2: Pipelining Functions
CREATE TYPE object_row_type AS OBJECT ( MYID NUMBER, MYCLOB CLOB ); CREATE TYPE object_table_type AS TABLE OF object_row_type; CREATE OR REPLACE FUNCTION GETCLOB RETURN object_table_type PIPELINED IS PRAGMA AUTONOMOUS_TRANSACTION; BEGIN insert into LocalTempTableWithClob Select * from RemoteTableWithClob@RemoteServer; commit; FOR cur IN (SELECT myid, myclob from LocalTempTableWithClob) LOOP PIPE ROW(object_row_type(cur.myid, cur.myclob)); END LOOP; DELETE FROM LocalTempTableWithClob; COMMIT; RETURN; END; create view myRemoteData as SELECT * FROM TABLE(GetClob) a; select myid, substr(myclob, 1, 5) mytext from myRemoteData; MYID MYTEXT -------------- 1 This 2 Anoth 3 One m
Solution 3: Dynamic SQL (till Oracle 9)
I don't know why, but for insert/update till Oracle 9 the only way to access LOB columns is to use dynamic SQL. So a quite simple solution is:
-- for insert excecute immediate 'insert into <Remote-Table>@<DB-Link> ( select * from <Local-Table> where ... )'; -- for update execute immediate 'update <Remote-Table>@<DB-Link> set <BLOB-Column> = ( <Subselect ...>)';
Example
declare l_sql varchar2(2000); l_id number; begin l_sql := 'update SAMPLE_TABLE_WITH_BLOB@REMOTE_SERVER set BLOB_COLUMN = (select BLOB_COLUMN from SAMPLE_TABLE_WITH_BLOB where ID = :ID)'; l_id := 7; execute immediate l_sql using l_id; end;