sybmigrate is the migration tool used to migrate data from one server to another.
By default, sybmigrate migrates encrypted columns in ciphertext format. This avoids the overhead of decrypting data at the source and encrypting at the target. In some cases, sybmigrate chooses the reencrypt method of migration, decrypting data at the source and encrypting at the target.
For databases with encrypted columns, sybmigrate:
Migrates the system encryption password. If you specify not to migrate the system encryption password, sybmigrate migrates the encrypted columns using the reencrypt method instead of migrating the ciphertext directly.
Migrates the encryption keys. You may select the keys to migrate. sybmigrate automatically selects keys in the current database used to encrypt columns in the same database. If you have selected migration of the system encryption password, sybmigrate migrates the encryption keys using their actual values. The key values from the sysencryptkeys system table have been encrypted using the system encryption password and these are the values that are migrated. If you have not migrated the system encryption password, sybmigrate migrates the keys by name, to avoid migrating keys that will not decrypt correctly at the target. Migrating the key by name causes the key at the target to be created with a different key value from the key at the source.
Migrates the data. By default, the data is transferred in its ciphertext form. Ciphertext data can be migrated to a different operating system. Character data requires that the target server uses the same character set as the source.
sybmigrate works on a database as a unit of work. If your database on the source server has data encrypted by a key in another database, migrate the key’s database first.
sybmigrate chooses to reencrypt migrated data when:
Any keys in the current database are specifically not selected for migration, or already exist in the target server. There is no guarantee that the keys at the target are identical to the keys are the source, so the migrating data must be reencrypted.
The system password was not selected for migration. When the system password at the target differs from that at the source, the keys cannot be migrated by value. In turn, the data cannot be migrated as ciphertext.
The user uses the following flag:
sybmigrate -T 'ALWAYS_REENCRYPT'
Reencrypting data can slow performance. A message to this effect is written to the migration log file when you perform migration with reencryption mode.
To migrate encrypted columns, you must have both sa_role and sso_role enabled.
| Copyright © 2005. Sybase Inc. All rights reserved. |
|
|
