[DISCUSS] Adapter's performance is not that fast

[Xiangwei Wei <wx...@gmail.com>]

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