Less-than/Greater-than WHERE Condition Push-down support

[CC-Hsu]

Hi,

We tested to query a foreign table with where condition to specify time interval (e.g. WHERE mytime >= '2018-05-01'::date ), but we found that it was very slow.

We later investigate source DB log and found that the source DB only receive SELECT SQL without the where condition.

Besides, we find that when we query only one column from a foreign table, which is created with IMPORT FOREIGN SCHEMA, all columns are queried in source DB. It seems that current odbc_fdw does not support column filtering yet.

Will odbc_fdw support richer push-down support and column filtering?

This will be a rich feature.

Thanks.