Provided by: lmdb-doc_0.9.17-3_all 

NAME
todo - Todo List
globalScope> Global MDB_rel_func )(MDB_val *item, void *oldptr, void *newptr, void *relctx)
This feature is currently unimplemented.
globalScope> Global mdb_set_relfunc (MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel)
The relocation function is called whenever it is necessary to move the data of an item to a different
position in the database (e.g. through tree balancing operations, shifts as a result of adds or
deletes, etc.). It is intended to allow address/position-dependent data items to be stored in a
database in an environment opened with the MDB_FIXEDMAP option. Currently the relocation feature is
unimplemented and setting this function has no effect.
Parameters:
txn A transaction handle returned by mdb_txn_begin()
dbi A database handle returned by mdb_dbi_open()
rel A MDB_rel_func function
Returns:
A non-zero error value on failure and 0 on success. Some possible errors are:
LMDB Mon Dec 28 2015 todo(3)