If the function is called again with the same parameter check if the something was changed in the database inbetween by looking at the time stamp of the log file. If there were no changes restore the values from memory. If there were changes load data again from database.

dbGetMemoise(
  db,
  table,
  params = NULL,
  schema = schemas[[table]],
  schemas = get.db.schemas(db),
  log.dir = NULL,
  refetch.if.changed = !is.null(log.dir),
  empty.as.null = FALSE,
  ...
)

Details

If refetch.if.changed = FALSE (default if no log.dir is provided), always use the data from memory.