CubeJS Tableau JDBC connector

CubeJS Tableau JDBC connector implemented based on postgres-jdbc connector but with some specific workarounds:

• added MEASURE aggregating function
• removed redundant CAST AS TEXT operation for string arguments

How to build the connector

• Create virtualenv for python

  make venv
  make setup

• Package the connector

  make pack

• Sign the connector (WIP) The following algorithm signs the taco file with self-signed certificate, which is not acceptable for Tableau Desktop by default.

  keytool -genkeypair -alias tableau -keyalg DSA
  keytool -exportcert -alias tableau -file /tmp/cert.cer
  keytool -certreq -alias tableau -file /tmp/cert.crt
  jarsigner packaged_connector/cubejs_jdbc-v0.0.0.taco tableau -tsa http://sha256timestamp.ws.symantec.com/sha256/timestamp -verbose -certs

  You can run Tableau Desktop with the following command then:

  open -n /Applications/Tableau\ Desktop\ 2023.1.app --args -DDisableVerifyConnectorPluginSignature=true

  On server, you can disable signature verification:

  tsm configuration set -k native_api.disable_verify_connector_plugin_signature -v true
  tsm pending-changes apply

TODO

• Implement connector testing with tdvt library
• Describe CONTRIBUTING guideline once testing framework is defined
• Add code-signing certificate to be able to run the connector in the usual way

Limitations

It's recommended to implement the following functions on cube level instead of building them in Tableau:

• ISO- date parts support: ISOYEAR, ISOQUARTER, ISOWEEK, ISODOW
• Date functions: DATEDIFF, DATEADD, DATENAME
• Statistic functions: CORR, COVAR, STD
• Strings comparison functions: >, >=, <, <=