Import

I had got an export of a database and had to import it to a new database. The only difference was that in new database few of the large tables were partitioned. So instead of partitioning it after the import, i thought about pre-creating the tables (with partitioning) and then run import with ignore=Y . Everything went fine. But later on the front end application gave some error and we came to know that default values for columns in some tables were not set. I did some googling and didn’t find much. Then i posted the same to OTN forums and came to know that if the table pre-exists, import doesn’t take care of default values of columns. Metalink note 224727.1 discusses this. So if you are pre-creating the tables and there are some default values for any columns, set it manually, don’t rely on import for this. Same is true for impdp as well. ...

Many times, we are required to restore a database from an export dmp file. Its a simple task but sometimes there are some issues left like invalid objects or some objects missing, in the newly created database. Following steps, followed in order can help in creating an error free database: Create a blank database:The very first step is to create a blank database which is to be used as the target database. That can be done using Database Configuration Assistant. (In last step of the DBCA, change redo log file sizes to 500 MB each (or some appropriate values depdening upon the size of the databaes), as during import, lot of redo will be generated, so large redo size helps in that scenario) ...