when to use flush()？

[jiankuny-zz]

should i user a timer to timely refresh the cache into index? i see there is a addCache and removeCache which default size is 300000, does it mean only when data size in cache large than 300000, will it add data into index?

[vcaesar]

You only need to call flush() once after the index, you can do other operations.

[jiankuny-zz]

so there is no way to timely flush cache into index? the only way is set the cache size smaller enough? because i want to dynamically add data into index