6.3 Restrictions on SQL Operations on LOBs

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

Table 6-2 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)...