About S3ToSQLOperator proposal

[robintian001]

Hi ALL

In my daily work, I use S3ToSqlOperator to synchronize S3 files to the database. However, when using it, I found some not very convenient things. For example, first of all s3_key must be a particularly clear path and cannot use a prefix for scanning, which means I have to unload the data from the data warehouse to a specific file in order to synchronize. Therefore, we implemented this function by ourselves through hook, but I'm not sure if this function is what the Airflow community expects or accepts.

Second: The execution performance of inserting databases in this Operator is very poor. The reason for this is that multiple insert statements are used for batch submission instead of using values (),(), and () for submission. Therefore, I have also carried out some custom development in this area