jdbc schema with postgres system catalogs

[Egor Ryashin]

Hi all,

i’m trying to validate a sql query against a Postgres database, probably I 
understand something incorrectly but I cannot find a good description how to 
reference Postgres system catalogs, I try different variations of this code but 
it fails:

Connection connection = DriverManager.getConnection("jdbc:calcite:");
CalciteConnection calciteConnection = 
connection.unwrap(CalciteConnection.class);
SchemaPlus rootSchema = calciteConnection.getRootSchema();
final DataSource ds = JdbcSchema.dataSource(
    "jdbc:postgresql://localhost:5432/postgres",
    "org.postgresql.Driver",
    "postgres",
    "postgres");
rootSchema.add("pg_catalog", JdbcSchema.create(rootSchema, "pg_catalog", ds, 
null, null));
FrameworkConfig config = Frameworks.newConfigBuilder()
                                   .defaultSchema(rootSchema)
                                   .build();

Planner planner = Frameworks.getPlanner(config);

SqlNode sqlNode = planner.parse("select * from pg_catalog.\"pg_tables\"");
System.out.println(sqlNode.toString());

sqlNode = planner.validate(sqlNode);
The exception is mostly this (I tried uppercase, lowercase and double quotes):

Caused by: org.apache.calcite.sql.validate.SqlValidatorException: Object 
‘pg_catalog' not found; did you mean ‘PG_CATALOG'?
        at 
java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native
 Method)
        at 
java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:77)
        at 
java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)

Thanks