Any plans on adding support for r2dbc spec

[meshpaul]

Hello,

Any plans on adding support for r2dbc spec I think this is next evolution of DB connectivity

I think your driver already exposes some of these concepts.

Thank you.

[joschi]

@meshpaul Do you think the MySQL interface together with https://github.com/mirromutth/r2dbc-mysql could be used for this?

[smagellan]

term "next evolution" may be problematic: https://twitter.com/jodastephen/status/1176186251277471747

[joschi]

term "next evolution" may be problematic: twitter.com/jodastephen/status/1176186251277471747

@smagellan That tweet was about the Asynchronous Database Access API (ADBA) project by Oracle, not R2DBC.

Also note that Oracle just released the official (!) R2DBC (!!) Driver for Oracle Database and even made it available on Maven Central (!!!), so I wouldn't exactly assume that R2DBC isn't a good candidate for implementation in a database driver. 😉

[smagellan]

@joschi Interesting, thank you

[zhicwu]

Thanks everyone for sharing your thoughts on this. However, I'd not suggest to simply build an adapter to bridge async calls to the JDBC driver.

There's a diagram in #570 illustrates the whole structure. Basically, in order to implement r2dbc driver, we need to:

• implement clickhouse-client and clickhouse-http-client/clickhouse-grpc-client/clickhouse-native-client first
  Note: clickhouse-jdbc will be refactored to use clickhouse-client.
• and then work on clickhouse-r2dbc by leveraging clickhouse-client(and optionally http/grpc/native providers)

I'm working on clickhouse-client and clickhouse-http-client, which will be available in 0.3.1. clickhouse-gprc-client can be generated quickly, so it will be added soon. I believe we can start to work on clickhouse-r2dbc in 0.4.0 or 0.3.2. In case you need a quick workaround, please consider mysql/postgresql interface as @joschi suggested.

[sneakythr0ws]

Has anyone tried mysql interface for https://github.com/mirromutth/r2dbc-mysql?
Seems like this bundle doesn't work together.
I tried and had a problem

Caused by: java.lang.IllegalArgumentException: Cannot decode value of type class java.lang.String for 3 with collation 63
	at dev.miku.r2dbc.mysql.codec.DefaultCodecs.decodeNormal(DefaultCodecs.java:212) ~[r2dbc-mysql-0.8.2.RELEASE.jar:0.8.2.RELEASE]
	at dev.miku.r2dbc.mysql.codec.DefaultCodecs.decode(DefaultCodecs.java:105) ~[r2dbc-mysql-0.8.2.RELEASE.jar:0.8.2.RELEASE]
	at dev.miku.r2dbc.mysql.MySqlRow.get(MySqlRow.java:59) ~[r2dbc-mysql-0.8.2.RELEASE.jar:0.8.2.RELEASE]
	at dev.miku.r2dbc.mysql.MySqlConnection.lambda$null$3(MySqlConnection.java:86) ~[r2dbc-mysql-0.8.2.RELEASE.jar:0.8.2.RELEASE]
	at dev.miku.r2dbc.mysql.MySqlResult.processRow(MySqlResult.java:176) ~[r2dbc-mysql-0.8.2.RELEASE.jar:0.8.2.RELEASE]
	at dev.miku.r2dbc.mysql.MySqlResult.handleResult(MySqlResult.java:149) ~[r2dbc-mysql-0.8.2.RELEASE.jar:0.8.2.RELEASE]
	at dev.miku.r2dbc.mysql.MySqlResult.lambda$map$1(MySqlResult.java:93) ~[r2dbc-mysql-0.8.2.RELEASE.jar:0.8.2.RELEASE]
	at reactor.core.publisher.FluxHandle$HandleSubscriber.onNext(FluxHandle.java:102) ~[reactor-core-3.4.5.jar:3.4.5]
	... 51 common frames omitted

As I understand this is the same issue
@joschi have you try it?

[zhicwu]

Now we have clickhouse-client, a semi-async library supporting both http and grpc. Would be great if anyone is interested to start a PR or new repo for clickhouse-r2dbc :)

Update: look at benchmark results for implementation based on JDK 11 HttpClient, no doubt r2dbc can bring us better performance.

[linghengqian]

Just confused, doesn't #914 solve this issue? Why is this issue not closed?

[zhicwu]

Hi @linghengqian, it's because I haven't test the r2dbc driver yet. I just quickly went over the code, added a few feedback along with some quick fixes.

Among all the issues I mentioned here, my biggest concerns are 1) lack of testing; 2) potential resource leaking(closing ClickHouseResponse etc.), and 3) exception handling. Actually I'm not quite sure about the last two, as I'm not familiar with r2dbc spec. Having said that, I think @rernas35 did great job creating the new module and I wouldn't mind to release what we have as part of v0.3.3 :)

Now we have nightly build at here, can someone please give it a shot and comment here? Any pull request is greatly appreciated :)