Restoring an Oracle Enterprise Edition DB into XE for use with APEX

Question

Hello, we're just in the process of decomissioning a load of servers and I came across an old Oracle DB box which has an install of APEX (well, HTMLDB) and a backend DB on an Enterprise Edition server, after battling with Oracle for 2 days I finally managed to get it to a state where I think it's restored successfully onto XE but up on the final "startup" I was presented with:
ORA-01092: ORACLE instance terminated. Disconnection forced
ORA-39712: XE edition server cannot open database
I really want\need to get this DB off of this server, because as you all probably know - Oracle DB EE isn't exactly cheap, and seen as though it's used for this historical app I kinda need to get it off of this hardware\software and into a low-end VM for it to chug away happily and be accessed when needs be...
Another option I though of, if I were to do a reinstall of XE, and then data pump the info from the EE to XE? Would that work?
I apologies for any numptiness in this question, but I really haven't got any experience with Oracle - and it's been a learning curve of much frustration coming from my easy to use MSSQL interfaces!
The steps I took were:
1) Run nid to rename the DB from "XE" to "ESTALTST"
a) Do some faffing about with tnsnames and listener.ora to get it to realise ESTALTST
2) Take a backup of logs\db from source
3) Catalog the backups
4) Restore control file
5) A lot of messing about getting the DB happy with the structures of things
6) recover database;
7) alter database resetlogs; <- this is where it said I had to do startup upgrade;
8) shutdown immediate; startup upgrade;
9) Where I am now.
Thanks,
Rich.

Answer 1

Just wondering, if the DB files are about 1Gb, should my dump file be 157Mb?I don't know, that depends on the actual amount of data stored in your database.
The filesize is no reliable measure for this. To give you a simple example: You have a "order entry" schema where you started storing your data 10 years ago. You initialized your data files with just a few megs and let Oracle do the extension automatically, so it grew and grew and is about 1 GB today. Now you decide that you don't need data that is older than two years in that schema and delete all outdated data. After you did that, your data files still be that 1 GB, though you only use about 20 percent of it. Oracle doesn't shrink your data files automatically...
To get a good estimation, you can run something like
SELECT f.file_name,
                        CEIL( f.bytes / 1024 / 1024 ) "SIZE_MB",
                        CEIL( f.bytes / 1024 / 1024 ) - FLOOR( SUM( NVL( fs.bytes, 0 ) ) / 1024 / 1024 ) "USED_MB",
                        FLOOR( SUM( NVL( fs.bytes, 0 ) ) / 1024 / 1024 ) "FREE_MB",
                        CEIL( f.maxbytes / 1024 / 1024 ) "MAX_MB"
                   FROM dba_free_space fs,
                        dba_data_files f
                  WHERE fs.file_id(+)     = f.file_id                   
               GROUP BY f.file_name,
                        f.bytes,
                        f.maxbytes,
                        f.blocks,
                        f.maxblocks,
                        f.autoextensible
               ORDER BY f.file_name;to see how much space is actually used in your data files. Note that this doesn't necessarily mean that your dump has to have that size. There are a few aspects (like compression) that could cause a difference...
-Udo