EXEC master.dbo.sp_addlinkedserver @server = N'MyLinkedServer', @srvproduct=N'MyLinkedServer', @provider=N'PGNP', @datasrc=N'N'MyLinkedServer', @provstr=N'PORT=5432;CNV_SPECIAL_FLTVAL=ON;', @catalog=N'MyDB'
...

Msg 7399, Level 16, State 1, Line 1
The OLE DB provider "PGNP" for linked server "MyLinkedServer" reported an error. Provider caused a server fault in an external process.
Msg 7350, Level 16, State 2, Line 1
Cannot get the column information from OLE DB provider "PGNP" for linked server "MyLinkedServer".

Microsoft SQL Server 2008 (SP4-GDR) (KB4057114) - 10.0.6556.0 (X64)   Dec 28 2017 15:21:01   Copyright (c) 1988-2008 Microsoft Corporation  Standard Edition (64-bit) on Windows NT 6.3 <X64> (Build 14393: ) 

Microsoft SQL Server 2019 (RTM-GDR) (KB4517790) - 15.0.2070.41 (X64)   Oct 28 2019 19:56:59   Copyright (C) 2019 Microsoft Corporation  Developer Edition (64-bit) on Windows Server 2019 Datacenter 10.0 <X64> (Build 17763: ) (Hypervisor) 

DECLARE @sql varchar(MAX) = 'SELECT * FROM
    OPENQUERY('+@serverName+', ''SELECT u.column1 as column1, u.column2 || '''' '''' || u.column3 as name,
        case
            when ...
            when ...
            ...
            else r.column end as type
    FROM '+@dbName+'.[schemaname].table1 c
    INNER JOIN '+@dbName+'.[schemaname].table2 ra ON ra.id=c.id
    INNER JOIN '+@dbName+'.[schemaname].table3 r ON r.id=ra.id
    INNER JOIN '+@dbName+'.[schemaname].table4 u ON u.id=ra.id
    INNER JOIN '+@dbName+'.[schemaname].table5 u2 ON u2.id=c.id
    WHERE ...)';
    EXEC (@sql);

DECLARE @sql varchar(MAX) = 'SELECT u.column1 as column1, u.column2 + '' '' + u.column3 as name,
        case
            when ...
            when ...
            ...
            else r.column end as type
    FROM '+@serverName+'.'+@dbName+'.[schemaname].table1 c
    INNER JOIN '+@serverName+'.'+@dbName+'.[schemaname].table2 ra ON ra.id=c.id
    INNER JOIN '+@serverName+'.'+@dbName+'.[schemaname].table3 r ON r.id=ra.id
    INNER JOIN '+@serverName+'.'+@dbName+'.[schemaname].table4 u ON u.id=ra.id
    INNER JOIN '+@serverName+'.'+@dbName+'.[schemaname].table5 u2 ON u2.id=c.id
    WHERE ...';
    EXEC (@sql);