Same here : using SQL Developer version 20.4.0.379, exported a table containing a CLOB column to Excel 2003+ (XLSX) format, only the records containing CLOBs smaller than 32 Kb were saved in the .XLSX file and the size of the generated file was 4 Kb (don´t mind the messages and the name of the file in Portuguese) :

C:\>dir C:\Users\Forms\exportar.xlsx
O volume na unidade C não tem nome.
O Número de Série do Volume é 5C20-573C

Pasta de C:\Users\Forms

14/05/2021 10:50 3.897 exportar.xlsx
1 arquivo(s) 3.897 bytes
0 pasta(s) 86.027.997.184 bytes disponíveis

https://support.microsoft.com/en-us/office/excel-specifications-and-limits-1672b34d-7043-467e-8e27-269d656771c3 documents
32,767 characters as Total number of characters that a cell can contain....

Using SQL DEVELOPER 20.4.0.379 Build 379.2205 (connect to a 10.2.0.5 EE database under Windows 2008 64-bits, in my case) , I have this table :

chiappa@DESENV:SQL>@desc TB_TESTE_CLOB_STR

Nome Nulo? Tipo
----------------------------------------- -------- ----------------------------
C1 NUMBER
C2 CLOB

With this data :

chiappa@DESENV:SQL>select c1, dbms_lob.getlength(c2) from TB_TESTE_CLOB_STR order by 1;

C1 DBMS_LOB.GETLENGTH(C2)
---------- ----------------------
1 76
2 102
3 0
4 11041
5 983012
6 32000
7 16

7 linhas selecionadas.

Problem is, exporting data to EXCEL 2003+ format (single file) I got an EMPTY cell for the data at line#5 column C2 (not only the first 32767 characters OR some kind of erros message/warning) AND I got no row for line#6 or line#7....
It appears to be some kind of buffer overflow when CLOB is greater than 32767 and from this point onwards, no data is exported....

Regards,

J. Laurindo Chiappa

Okdoc, LOBs greather than 32 kb are not exported , granted... But what about my example, where the small LOB in the next record after the big LOB is not exported, could it be a bug ?

Regards,

Chiappa

SQL> create table t ( pk int, c clob );

Table created.

SQL> insert into t values (1, rpad('x',1000,'x'));

1 row created.

SQL> insert into t values (2, rpad('y',32000,'y'));

1 row created.

SQL> insert into t values (3, rpad('z',32000,'z'));

1 row created.

SQL> update t
  2  set c = c||c||c||c
  3  where pk = 3;

1 row updated.

SQL> insert into t values (4, rpad('x',1000,'x'));

1 row created.

SQL> insert into t values (5, rpad('y',32000,'y'));

1 row created.

SQL> commit;

Commit complete.