Обсуждение: the same time value return different values，is it a problem

I find the time type accuracy of the database. Using PreparedStatement, the accuracy found out for the sixth time is different from the first five times. This number is exactly the same as the threshold of the PreparedStatement. I can understand that the database can optimize PreparedStatements and reduce repeated parsing and other unnecessary operations. but I don’t quite understand how such processing will affect the execution results(Or maybe I don’t have a deep understanding of PreparedStatement.). now I run the code and get some results；

=?utf-8?B?5aec5qKm5rSL?= <minesunny@icloud.com> writes:
>     I find the time type accuracy of the database. Using PreparedStatement, the accuracy found out for the sixth time
isdifferent from the first five times. This number is exactly the same as the threshold of the PreparedStatement. I can
understandthat the database can optimize PreparedStatements and reduce repeated parsing and other unnecessary
operations.but I don’t quite understand how such processing will affect the execution results(Or maybe I don’t have a
deepunderstanding of PreparedStatement.). 

If you're using JDBC, this is probably the same effect discussed at

https://www.postgresql.org/message-id/flat/CAKyg5Sj%3D85niw8%3DZhX-quHaCQTPhG40REi1s%2BHYF6Snz4Dfi7Q%40mail.gmail.com

It's got something to do with retrieving the query results in binary
mode instead of text.  The query result at the server is the same,
but the JDBC driver is rendering it differently.

            regards, tom lane