lightdb lt_bulkload，比copy更高效的导入方式以及jdbc copy实现

https://www.cnblogs.com/liuyuanyuanGOGO/archive/2013/05/08/3066646.html

https://jdbc.postgresql.org/documentation/publicapi/org/postgresql/copy/package-summary.html

https://ossc-db.github.io/pg_bulkload/pg_bulkload.html

参见https://www.cnblogs.com/zhjh256/p/16705038.html