All of the access method database formats changed in the Berkeley DB 4.1 release (Btree/Recno: version 8 to version 9, Hash: version 7 to version 8, and Queue: version 3 to version 4). The format changes are entirely backward-compatible, and no database upgrades are needed. Note, however, that databases created using the 4.1 release may not be usable with earlier Berkeley DB releases.
The log file format changed in the Berkeley DB 4.1 release.
For further information on upgrading Berkeley DB installations, see Upgrading Berkeley DB installations.
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