Storage allocation at full import with no rows

Question

The export was done with rows=n on the main server Oracle ver 8. To import the dump, it seems the disk volume needs to be as big as on the server (even though no data are imported).
On the computer we are using for the import there is not enough disk space. I tried to preprocess the dump and replace INITIAL storage parameters of all objects to be minimal 4K. I cannot go beyond 16K at the table creation. I think that tablespace creation should be suited differently?
Do you have any other idea how the dump with rows=n can be imported to the computer with smaller disk volume than original machine? (i.e. 40 GB instead 300 GB)

Answer 1

The imp process is aware of the storage allocation information on the objects exported and is influenced by the compress=y|n option used on export.
On import Oracle will attempt to create the tables and indexes using the storage clause information extracted from production in conjunction with the target tablespace storage parameters to pick a size to use in allocation of the object.
With dictionary management on both sides and the default compress=n on exp in use, imp will attempt to create the table or index with a single extent equal to the object allocation size on production. This can quickly exhaust the test space. When uniform extents are in use Oracle will pre-allocate enough extents to equal the requested size (at least in 8i).
I suggest you make the export with compress=n and pre-allocate any large objects you want/need to shrink. This will require using the ignore=y option on the import. When test is only a fraction of the size of production you may find it necessary to pre-allocate all your objects the first time you refresh from production to resize everything.
HTH -- Mark D Powell --