ORA-01460: unimplemented or unreasonable conversion requested

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I saw this somewhat cryptic error message while using my Oracle Regular Expression Workbench tool, before i restricted the size of the sample (multiline) string to 4000 bytes.

This error can be quickly simulated in the following fashion:

create table test_1460(string_col varchar2(4000));

declare
str1   varchar2(4001) := rpad(' ',4001);
str2  varchar2(4000);
begin
execute immediate 'select :sample_string from test_1460 ' into str2 using str1;
end;

Error report:
ORA-01460: unimplemented or unreasonable conversion requested
ORA-06512: at line 5

The problem is with the size of bind variable str1 that exceeds 4000 bytes.

You can also get the same error while using SQL Developer with a simple query containing a bind variable as follows:

select :sample_string as s
from dual;

when the pop-up window asking for the value to be passed to the bind variable appears, enter a large string, longer than 4000 bytes and you will get ORA-01460.


See message translations for ORA-01460 and search additional resources.