commit 95bf642fa9d7c9917f45b51e3e89e53e16e56ae5
author Sergii Zhevzhyk <vzhikserg@users.noreply.github.com> Mon May 18 22:53:51 2020 +0200
committer GitHub <noreply@github.com> Mon May 18 13:53:51 2020 -0700
tree 69bf01933bc8acf62b4c0d2c08a4a5cbf69a0ee3
parent 0e85a3cadb29e48da6ae77e025bf2945438416f7

[Issue 5215,4601,5215][pulsar-io] Add jdbc sinks: postgres, mariadb, clickhouse (#6835)

Fixes #5215  #4601 #5215

### Motivation

Right now, the number of supported JDBC connectors is rather limited. There are a couple of open issues related to the missing connectors. 

### Modifications

As a base for this pull request, I took the [changes](https://github.com/apache/pulsar/pull/5624) from @huangdx0726 Unfortunately,  I was not able to reach him to merge my changes to his branch, so I created a new one.

The main modification is a split of one JDBC module into a bunch of them. One module serves as a core and provides the main logic of the connector. Other modules are real connectors and add only an appropriate JDBC driver.