For the first time it is indeed slow, because it has startup cost and code generation. Can you post how you test it (by single run or multiple runs) and how does the flame graph look like?
- Haisheng ------------------------------------------------------------------ 发件人：Xiangwei Wei<[email protected]> 日 期：2020年02月26日 14:01:16 收件人：<[email protected]> 主 题：[DISCUSS] Adapter's performance is not that fast Hi everyone. My name is Xiangwei Wei and I'm new here. I wrote an adapter for Apache IoTDB recently which is a database for time series data management to support use of Apache Calcite. However, when I finished it and tried to test its performance, I found 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
