Oracle 10.2.0.3 apparent XML bug

Question

A very simply query using 'string-join' fails but works with 'concat'. The error we get is: ORA-19112: error raised during evaluation: java.lang.OutOfMemoryError
The basic query is (its attempting to join "_A" to about 5000 rows - see the query below) :
xquery for $x in ora:view("USER_A","TABLE_A")/ROW
where $x/ITEM_ID/text() ne 999
return
<a>{string-join(($x/ITEM_ID/text(),"A"),"_")}</a>
Is this a bug and will it be fixed when 10.2.0.4 comes out?
Thankyou for your assistance

Answer 1

I think you compare apples with oranges. string-join and concat behave very differently and are not interchangeable:
michaels>  CREATE TABLE table_a
AS SELECT '999' item_id FROM DUAL UNION ALL
SELECT '997' item_id FROM DUAL UNION ALL
SELECT '998' item_id FROM DUAL UNION ALL
SELECT '999' item_id FROM DUAL
Table created.
michaels>  select * from XMLTable('for $x in ora:view("TABLE_A")/ROW
                        where $x/ITEM_ID/text() ne "999"
                         return <i>{string-join(($x/ITEM_ID/text(),"A"),"_")}</i>')
COLUMN_VALUE   
<i>997_A</i>   
<i>998_A</i>   
2 rows selected.
michaels>  select * from XMLTable('for $x in ora:view("TABLE_A")/ROW
                        where $x/ITEM_ID/text() ne "999"
                         return <i>{concat(($x/ITEM_ID/text(),"A"),"_")}</i>')
Error at line 1
ORA-19279: XQuery dynamic type mismatch: expected singleton sequence - got multi-item sequence
michaels>  select * from XMLTable('for $x in ora:view("TABLE_A")/ROW
                        where $x/ITEM_ID/text() ne "999"
                         return <i>{concat($x/ITEM_ID/text(),"A","_")}</i>')
COLUMN_VALUE   
<i>997A_</i>   
<i>998A_</i>   
2 rows selected.