Oracle Import and Export tips

Export directly
Exp system/manager file = exp_full.dmp log = exp_full.log compress = N full = y direct = y recordlength = 65535
View exported file content
IMP username/password show = y full = y file = A. dmp

Export option: compress = n to ensure that the data is not merged into an extent.

IMP Acceleration
(2) Add a sorting area
(3) Adjust the buffer Option
IMP user/pwd fromuser = user1 touser = user2 file =/tmp/imp_db_pipe1 commit = y feedback = 10000 buffer = 10240000

If the buffer size is too large, an imp-00032 imp-00008 error occurs.
(4) use the commit = Y option
Commit = y indicates that each data buffer is submitted once, instead of importing a table. This will greatly reduce the consumption of resources such as system rollback segments, and will be helpful for the smooth completion of the import.
(5) use the indexes = n Option
When we talk about adding a sorting area, it means that the IMP process will first import data and then create an index.
During the import process, we can use indexes = n to import only data without creating indexes, thus speeding up the import.
You can use the indexfile option to generate the index creation dll script, and then manually create the index. We can also use the following method to import data twice, the first time to import data, and the second time to import indexes. The usage is as follows:
IMP user/pwd fromuser = user1 touser = user2 file =/tmp/imp_db_pipe1 commit = y feedback = 10000 buffer = 10240000 ignore = y rows = y indexes = N
IMP user/pwd fromuser = user1 touser = user2 file =/tmp/imp_index_pipe1 commit = y feedback = 10000 buffer = 10240000 ignore = y rows = n indexes = y

Delete a tablespace
Drop tablespace dataflow including contents and datafiles cascade constraints;