Identifier problem in IBM System i

[boskowski]

An IBM System i is connected to PostgreSQL 9.6 on Ubuntu 16.04 via IBM ODBC Driver and (patched) odbc_fdw. After successfully importing the table definition with IMPORT FOREIGN SCHEMA, I'm unable to query the table, e.g.:

# select * from notes;
ERROR:  Executing ODBC query

Independently of the query issued, the wrapper executes a count on the table. The ODBC trace file shows the following:

[ODBC][9958][1479471907.875547][SQLExecDirect.c][240]
  Entry:
    Statement = 0x558aa88944b0
    SQL = [SELECT COUNT(*) FROM (SELECT * FROM NOTES) AS _odbc_fwd_count_wrapped][length = 69 (SQL_NTS)]
[ODBC][9958][1479471907.882163][SQLExecDirect.c][503]
    Exit:[SQL_ERROR]
    DIAG [42000] [IBM][System i Access ODBC Driver][DB2 for i5/OS]SQL0104 - Token _ was not valid. Valid tokens: CL ID IN ASC LOG OUT DATA UNIT COLLECT <IDENTIFIER>.

DB2/i5 identifiers cannot start with an underscore.

Ideas for a workaround? Thank you!

[g-r-u]

Go to line 849 in odbc_fdw.c and remove the underscore from the column alias. You'll probably have to rebuild and compile. Does anyone know of a good reason not to remove the underscore for good?

[vazeswapnil]

Hello,

I am trying to access DB2 table from postgresql 9.5 using odbc_fdw. I was receiving same error, so I modified underscore as suggested and rebuild it. Now whenever I select data from foreign table it crashes with below error.
postgres=# select * from odbc_table;
server closed the connection unexpectedly
This probably means the server terminated abnormally
before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.
!> \q

I ran the trace command on odbc and attached is output.
trace.docx

[rafatower]

Please share the traces in plain text if you don't mind

[vazeswapnil]

Hello,
I have copied output to text file.
trace.txt

[vazeswapnil]

Hello,

Just wanted to check if we had any solution or alternative for this.