Hallvard Breien Furuseth: >> Sofar the abstraction layer already hides the LMDB-specific MAP_FULL >> and MAP_RESIZED error conditions. If this abstraction layer needs >> additional code in order to maintain MDB cursor sanity, then please >> educate me. > > ldmb.h says -- > > mdb_env_set_mapsize(): > "It may be called at later times if no transactions are active in > this process. Note that the library does not check for this condition, > the caller must ensure it explicitly." > MDB_NOLOCK: > "[caller] must ensure that no readers are using old transactions > while a writer is active. The simplest approach is to use an > exclusive lock so that no readers may be active at all when a writer > begins." > > That's why I talked about saving the cursor position and restoring it - > cursors are per-transaction and you need a new transaction. I can remember the last key from mdb_cursor_get() and set the cursor to that key. There does not appear to be a cursor "save" operation in the API documentation http://symas.com/mdb/doc/group__mdb.html.