Reference - Compatibility Client version and database version corresponding to the server version are as follows.
Server version Client Database
Internal version Client version Internal version Server version when DB was created
v 1.0 1 v 1.0/1.1 1 v 1.0
v 1.1 1 v 1.0/1.1 1, 2 v 1.0/1.1
v 1.5 2 v 1.5 1, 2, 3 v 1.0/1.1/1.5
v 2.0 3 v 2.0 4 v 2.0
v 2.1 4 v 2.1 5 v 2.1
v 2.5 5 v 2.5 5 v 2.1/2.5
v 2.7 5, 6 v 2.5/2.7 5, 6 v 2.1/2.5/2.7
<Memo> Internal version is the version used for internal processing displayed in the error message.