Export/import oracle9

Question

Hi,
since I do not have a good knowledge of oracle, hopefully somebody may help me to understand better how export/import work (oracle 9)
A colleague as run an export from a production server, now he needs to run the import on a test server but it fails.
Could someone be so kind to let me know what I have to take into consideration before running both commands ?
I explain better:
I have noticed that the DB_BLOCK_SIZE is indeed different on the two servers (production server has a DB_BLOCK_SIZE=4096)(test server has a DB_BLOCK_SIZE=8192)
so the first thing I have seen in the import log file is an error message saying that "tablespace block size 4096 does not match configured block sizes"
So my first question would be: is there any chance to run export/import on two servers with different DB_BLOCK_SIZE ?
Then (due to my ignorance of the subject):
- is there any problem is the SID is different on the two servers ? or it is not important ?
- is it important that the PATH of "*dbf" files is different on the two servers or this fact is not taken into consideration at all (since only 'logical' data are taken into consideration) ?
- do the tablespaces currently used on the production server have to exist in the test server in order to have a successful import ?
Hopefully somebody has few minutes to answer my question.
Thanks a lot in advance.

Answer 1

Hi,
Are you talking about FULL export/import method, right? Well, Oracle 9i supports multiple block sizes in the same database. So, it gives you an option of using multiple block sizes, which is especially useful when you are transporting tablespaces from another database with a different block size. In this case, will be necessary to set the initialization parameter called DB_nK_CACHE_SIZE in the initialization parameter file. For example, in your case, if your standard block size is 8KB, you will need to pre-create a tablespace with a block size, say 4KB that are currently using on your product server and then you will must set the DB_4K_CACHE_SIZE parameter in your test server. The DB_nK_CACHE_SIZE The parameter is dynamic so you can alter its value using the ALTER SYSTEM statement.
>>- is there any problem is the SID is different on the two servers ? or it is not important ?
No problem ...
>>- is it important that the PATH of "*dbf" files is different on the two servers or this fact is not taken into consideration at all (since only 'logical' data are taken into consideration) ?
In fact, It is important that the tablespace exists in the target database and doesn't matter where they datafiles are located. In this case, logical data are taken into consideration.
>>do the tablespaces currently used on the production server have to exist in the test server in order to have a successful import ?
Yes. For a full import method, this is very important. So, you will need to pre-create the tablespaces in your target tablespaces, but in this case they need to be created with 4k of block size, as I said before. Anyways, you will need to make some tests.
Otherwise, if you want to make a test, create a database on you test server using 8k default block size and use the export user method instead.
Eg.:
If you have the user A, B and C using the TBS_1 in your prod database, so, create the tablespace TBS1 using the default block size (8k) in your test database and make this test below:
PROD DATABASE
exp a/pass file=a grants=n
exp b/pass file=b grants=n
exp c/pass file=c grants=n
TEST DATABASE
create the users A,B and C and perform these tasks below:
imp a/pass file=a full=y
imp b/pass file=b full=y
imp c/pass file=c full=y
In addition, give a feedback ....
Cheers
Legatti