adjust SPLIT_LIMIT to 64, to reduce memory usage
adjust SPLIT_LIMIT to 64, to reduce memory usage

amyvmiwei/beansdb,mashuai/beansdb,mruse/beansdb,mruse/beansdb,mashuai/beansdb,mruse/beansdb,donglei/beansdb,donglei/beansdb,donglei/beansdb,donglei/beansdb,mashuai/beansdb,amyvmiwei/beansdb,amyvmiwei/beansdb,mashuai/beansdb,amyvmiwei/beansdb,mruse/beansdb