Document that Greenplum can be used via PostgreSQL VS

[redcatbear]

Situation

John reported that he was able to connect to Greenplum via PostgreSQL VS.

Acceptance Criteria

1. VS documentation states that the PostgreSQL VS can be used to connect to green plum too.

[redcatbear]

John's test case:

CREATE OR REPLACE JAVA ADAPTER SCRIPT GREENPLUM.JDBC_ADAPTER AS
  %scriptclass com.exasol.adapter.RequestDispatcher;
  %jar /buckets/bucketfs1/test_joth/virtual-schema-dist-5.0.4-bundle-4.0.3.jar;
  %jar /buckets/bucketfs1/test_joth/postgresql-42.2.18.jar;
/

CREATE OR REPLACE CONNECTION GREENPLUM_CONNECTION
TO 'jdbc:pivotal:greenplum://18.184.33.126:5432;DatabaseName=dev&prepareThreshold=0'
USER 'exasol_admin'
IDENTIFIED BY 'Exasol';

CREATE OR REPLACE CONNECTION GREENPLUM_CONNECTION
TO 'jdbc:postgresql://18.184.33.126:5432/dev?prepareThreshold=0'
USER 'exasol_admin'
IDENTIFIED BY 'Exasol';

select * from (import from jdbc at GREENPLUM_CONNECTION statement 'select * from trading.trades limit 100');

CREATE VIRTUAL SCHEMA GREENPLUM2
 USING GREENPLUM.JDBC_ADAPTER
 WITH
 SQL_DIALECT = 'POSTGRESQL' 
 SCHEMA_NAME = 'trading'
 CONNECTION_NAME = 'GREENPLUM_CONNECTION'
 IGNORE_ERRORS = 'POSTGRESQL_UPPERCASE_TABLES';

[chiaradiamarcelo]

Closing and moved to https://github.com/exasol/postgresql-virtual-schema/issues/10