Garbled Text Garbled data was found after importing a normal dump file. After doing some inspections, I found there’s NLS_LANG environment variable for user oracle in the source database server, but no NLS_LANG in the target server. Default Character Set of Sessions Since there’s no NLS_LANG to set NLS parameters at session-level, the import session […]
The direct answer is: If they are in subset-superset relationship, you can change the character set without change it. So maybe your next question is: Where do we find the relationship?According to the official supeset-subset relationship table. Table A-11 Binary Subset-Superset Pairs. You can see that very limited pairs in this table and there’s only UTF-8 […]
Assuming that you have exported all the data to dump file for further process. Please shutdown the database.SQL> column parameter format a25;SQL> column value format a25;SQL> select parameter, value from v$nls_parameters where parameter like ‘%CHARACTERSET%’;PARAMETER VALUE————————- ————————-NLS_CHARACTERSET ZHT16MSWIN950NLS_NCHAR_CHARACTERSET AL16UTF16SQL> shutdown immediate;Database closed.Database […]
BYTE vs CHAR in NLS_LENGTH_SEMANTICS Most of databases set NLS_LENGTH_SEMANTICS as BYTE by default, but there are some databases in Non-English country will take CHAR as the default unit of data type for CHAR and VARCHAR2.