ORA-12899 – Value too large for column string

有空再翻译吧

If we need to recover a scheme which default LANG is WE8ISO8859P1 and our database is AL32UTF8, the import process crash because the special characters during the conversion pass from one byte to two:

Column 12 LA APLICACION EN ESPA?A DEL CONVENIO DE LA HAYA DE...
IMP-00019: row Rejected due to Oracle error 12899
IMP-00003: ORACLE Error 12899 Encountered
ORA-12899: value too large for column "SCHEME". "TABLE". "ROW" (actual: 51, maximum: 50)

To resolved this problem we’ll need changing columns to CHAR length semantics, following this steps:

• Export the original database
• Import only the table definitions into the new database, without inserting the rows (ROWS=N import)
• Converts columns to CHAR length semantics
• Import the rows

• 1 Export
• 2 Table definitions
• 3 CHAR conversion
• 4 Import Data

Export

Export the scheme to the directory MY_BCK, ensure that MY_BCK exists:

SQL> CREATE OR REPLACE DIRECTORY MY_BCK AS '/u01/app/oracle/bck/';

Run the export with SYSTEM user, and datapump utility:

SQL> expdp system/password schemas=SCOTT directory=MY_BCK dumpfile=SCOTT.dmp logfile=expdpSCOTT.log

Or with conventional export system:

SQL> exp system/password owner=SCOTT file=/u01/app/oracle/bck/SCOTT.dmp log=/u01/app/oracle/bck/expdpSCOTT.log

Table definitions

Import only the definitions of the tables, no the rows

SQL> impdp system/password schemas=SCOTT directory=MY_BCK dumpfile=SCOTT.dmp logfile=impdpSCOTT.log content=metadata_only

SQL> imp system/password fromuser=SCOTT touser=SCOTT file=/u01/app/oracle/bck/SCOTT.dmp log=/u01/app/oracle/bck/expdpSCOTT.log ignore=Y ROWS=N

CHAR conversion

To facilitate this process, Oracle created this script. You only need to edit the name of your scheme:

Conn / as sysdba
set feedback off
set verify off
set serveroutput on
set termout on
exec dbms_output.put_line('Starting build select of columns to be altered');
drop table semantics$
/
create table semantics$(s_owner varchar2(40),
s_table_name varchar2(40),
s_column_name varchar2(40),
s_data_type varchar2(40),
s_char_length number)
/
insert into semantics$
select C.owner, C.table_name, C.column_name, C.data_type, C.char_length
from all_tab_columns C, all_tables T
where C.owner = T.owner
and T.owner in
('SCOTT')
-- All Oracle provided users
and C.table_name = T.table_name
and C.char_used = 'B'
-- only need to look for tables who are not yet CHAR semantics.
and T.partitioned != 'YES'
-- exclude partitioned tables
and C.table_name not in (select table_name from all_external_tables)
and C.data_type in ('VARCHAR2', 'CHAR')
-- You can exclude or include tables or shema's as you wish, by adjusting
-- "and T.owner not in" as per your requirements
/
commit
/
declare
cursor c1 is select * from semantics$;
v_statement varchar2(255);
v_nc number(10);
v_nt number(10);
begin
execute immediate
'select count(*) from semantics$' into v_nc;
execute immediate
'select count(distinct s_table_name) from semantics$' into v_nt;
dbms_output.put_line
('ALTERing ' || v_nc || ' columns in ' || v_nt || ' tables');
for r1 in c1 loop
v_statement := 'ALTER TABLE ' || r1.s_owner || '.' || r1.s_table_name;
v_statement := v_statement || ' modify (' || r1.s_column_name || ' ';
v_statement := v_statement || r1.s_data_type || '(' || r1.s_char_length;
v_statement := v_statement || ' CHAR))';
execute immediate v_statement;
end loop;
dbms_output.put_line('Done');
end;
/

Recompile the scheme to validate dependent objects:

SQL> EXECUTE UTL_RECOMP.RECOMP_PARALLEL(4);

Import Data

To finish importing the data scheme

SQL> impdp system/password schemas=SCOTT directory=MY_BCK dumpfile=SCOTT.dmp logfile=impdpSCOTT.log

SQL> imp system/password fromuser=SCOTT touser=SCOTT file=/u01/app/oracle/bck/SCOTT.dmp log=/u01/app/oracle/bck/expdpSCOTT.log ignore=Y