Hi.
I'm so sorry about that. I'm new in Apache community and am not familiar with dev email. I wrote this letter from QQ Mail before, but I forgot to subscribe calcite dev then. So I subscribed it and resend the email from gmail which was the email replied by Haisheng before. I thought the email from QQ was lost because of unsubscribing, but somehow it appeared today. I'm so sorry... And thanks for reminding, I checked the email from Haisheng to ask further clarifications, I found the auto reply didn't add dev email......so you can't receive my reply. I will resend it then. Best, Xiangwei Wei ------------------ ???????? ------------------ ??????: "Stamatis Zampetakis"<[email protected]>; ????????: 2020??3??2??(??????) ????3:54 ??????: "dev"<[email protected]>;"??????"<[email protected]>; ????: Re: [Discuss] Adapter's performance is not that fast Hi Xiangwei, Haisheng already replied to this thread asking some further clarifications [1]. Is there a reason that you are resending the email multiple times? Best, Stamatis [1] https://lists.apache.org/thread.html/r0163d54fdf001ebc0303e3a796b2c41272c111bdac72e10a8dbb9a7c%40%3Cdev.calcite.apache.org%3E On Sat, Feb 29, 2020 at 11:51 PM ?????? <[email protected]> wrote: Hi everyone. My name is Xiangwei Wei and I'm new here. I wrote an adapter for Apache IoTDB recently which is&nbsp;a database for time series data management to support use of Apache Calcite.&nbsp; However, when I finished it and tried to test its performance, I found&nbsp;the adapter's performance was not that fast. It took much time compared with the raw data query in the database backend. I thought maybe it was the problem of my adapter. So I did the same test on the Cassandra Adapter which is provided by Calcite source code. But it shew similar result. Executing a simple query using Cassandra Adapter takes about 1600ms - 1800ms on my PC. However, it costs only 5 ms to do the raw data query in the Cassandra database backend. Is this the general performance of adapters? Or I made something wrong? I did the test by writing a simple JDBC program to do query using standard sql. For Cassandra Adapter, I used the data proviced in "./cassandra/src/test/resources/twissandra.cql" and a simple sql statement provided in the CassandraAdapterTest which is "select * from \"userline\" where \"username\"='!PUBLIC!'". Best, Xiangwei Wei &nbsp;
