* fix set config issue
Signed-off-by: Nyudong.cai <yudong.cai@zilliz.com>

* add auto_flush_interval observer in DBImpl
Signed-off-by: Nyudong.cai <yudong.cai@zilliz.com>

* fix some issues in SegmentReader
Signed-off-by: Nyudong.cai <yudong.cai@zilliz.com>

* update CreateCollection interface
Signed-off-by: Nyudong.cai <yudong.cai@zilliz.com>

* fix clang-format
Signed-off-by: Nyudong.cai <yudong.cai@zilliz.com>

* update
Signed-off-by: Nyudong.cai <yudong.cai@zilliz.com>