Dear Julian,
Have a good day.
Yes. I have tried to connect to kylin via JDBC adapter, but the sql string has
been changed to which kylin engine does not support(sql string was parsed not
correctly ).
The sql query process i understand is that :
avatica jdbc driver gets connection and sumit sql string -->avatica server
receives the sql string->calcite convertes the sql string to a logical plan-->
calcite applys planning rules to optimize the query process--> calcite converts
the sql string back and submits it to the database.
The description above is right?
I am wondering if it is possible to bypass the logical plan convertion. After
avatica server receives the sql string, calcite posts the sql string to kylin
rest server by kylin jdbc driver defined in the json model file? As you can
see, the implements of kylin jdbc is as following:
1.register kylin jdbc driver
2.get statement
3.set query sql string and execute query( excute query by posting sql string to
kylin rest server)
If bypass issue could be carried out to query kylin, there might be a point to
bypass the convertion to logical plan.
----------------------------------------------------------------------------------------------------------------------------
My avatica server source archive is as following:
----project name----
--java code--
+BiQueryServer.java
+ModelMetaFactory.java
--resources--
+model.json
--------------------------------------------BiQueryServer.java---------------------------------------------------------------------
public class BiQueryServer {
public static void main(String[] args) {
List<String> argsList = new ArrayList<String>();
argsList.add("com.w3sun.sqlengine.ModelMetaFactory");
argsList.add("org.apache.calcite.avatica.jdbc.JdbcMeta");
for (String arg : args) {
argsList.add(arg);
}
String[] argsArray = (String[]) argsList.toArray(new
String[argsList.size()]);
try {
org.apache.calcite.avatica.server.Main.main(argsArray);
} catch (InterruptedException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InstantiationException e) {
e.printStackTrace();
}
}
}
------------------------------------------------ModelMetaFactory.java-----------------------------------------------------------------------------
public class ModelMetaFactory implements Meta.Factory {
private final String modelFile =
this.getClass().getResource("/model.json").getPath().substring(1);
private final String localJdbcUrl = "jdbc:calcite:";
public void printMetaInfo(String meta) {
System.out.println("[TnpmConnectionFactory.create] Implement with " +
meta);
}
public Meta create(List<String> list) {
try {
if (list.size() > 0 &&
list.get(0).equals("org.apache.calcite.avatica.jdbc.JdbcMeta")) {
return new JdbcMeta(localJdbcUrl + "model=" + (list.size() > 1
? list.get(1) : modelFile));
} else {
return null;
}
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
}
----------------------------------------------model.json------------------------------------------------------
{
"version": "1.0",
"defaultSchema": "kylin",
"schemas": [
{
"name": "kylin",
"type": "custom",
"factory": "org.apache.calcite.adapter.jdbc.JdbcSchema$Factory",
"operand": {
"jdbcDriver": "org.apache.kylin.jdbc.Driver",
"jdbcUrl":"jdbc:kylin://192.18.23.15:7070/test_project",
"jdbcUser": "ADMIN",
"jdbcPassword": "KYLIN"
}
}
]
}
Best Regards
Neters
------------------ ???????? ------------------
??????: "Julian Hyde";<[email protected]>;
????????: 2018??2??3??(??????) ????2:31
??????: "dev"<[email protected]>;
????: Re: Adjust clacite to support kylin query
Have you tried connecting to Kylin (and MySQL) via the JDBC adapter?
(I know Kylin has Calcite inside, but they don??t package it as an adapter, so
we??re forced to treat them as a black box.)
Julian
> On Feb 2, 2018, at 4:13 AM, Neters <[email protected]> wrote:
>
> Hi guys,
>
> Good day.
>
> Sorry guys,the mail system remove my pic, so i make it attachment.
>
> I want to query apache kylin by calcite,but i did not find the adapter for
> kylin. So i decide to modify the code attached in kylin source code.
> My frame like this:
>
> avatica jdbc client
> |
> |
> -------------------------
> | calcite |
> --------------------------
> / | \
> kylin es mysql
>
>
>
>
> Could you please give some constructive support?
>
> Best Regards
>
>
