1. SecureFiles and Large Objects Developer's Guide
  2. SQL Semantics for LOBs
  3. Restrictions on SQL Operations on LOBs

5.3 Restrictions on SQL Operations on LOBs

There are many SQL operations that are not supported on LOB columns. This section lists those operations.

Table 5-2 Unsupported Usage of LOBs in SQL

SQL Operations Not Supported Example of unsupported usage

SELECT DISTINCT

SELECT DISTINCT clobCol from...

SELECT clause

ORDER BY

SELECT... ORDER BY clobCol

SELECT clause

GROUP BY

SELECT avg(num) FROM...

GROUP BY clobCol

UNION, INTERSECT, MINUS

(Note that UNION ALL works for LOBs.)

SELECT clobCol1 from tab1 UNION SELECT clobCol2 from tab2;

Join queries

SELECT... FROM... WHERE tab1.clobCol = tab2.clobCol

Index columns

CREATE INDEX clobIndx ON tab(clobCol)...

Related Topics

Parent topic: SQL Semantics for LOBs