[Python-sybase-misc] Weird ct_results at the end of fetchone()

[Bock, O. B. S. <Oli...@ba...>]

I am connecting to Sybase IQ/12.6.0 using python-sybase and Adaptive
Server IQ Network Client 12.6 on Windows XP.  Everything works fine for
small queries, but a very large query (73000 rows returned) fails like
this:

Traceback (most recent call last):
  File "C:\workspace\AlphaExplorer\sql.py", line 19, in ?
    row =3D curs.fetchone()
  File "C:\Python24\Lib\site-packages\Sybase.py", line 817, in fetchone
    return self._fetcher.fetchone()
  File "C:\Python24\Lib\site-packages\Sybase.py", line 555, in fetchone
    self._fetch_rowcount()
  File "C:\Python24\Lib\site-packages\Sybase.py", line 682, in
_fetch_rowcount
    self._raise_error(Error, 'ct_results returned result %s' %
str(result))
  File "C:\Python24\Lib\site-packages\Sybase.py", line 519, in
_raise_error
    raise exc(text)
Sybase.Error: ct_results returned result 4040

This error occurs after I have fetched the last row.  (That is, I expect
it to return None, indicating that there is nothing left.)

Note that I have modified _fetch_rowcount to give information on the
result code returned, and it is 4040, which may correspond to
CS_ROW_RESULT, although I cannot work out why this should be returned at
this time.

I can work around the problem by catching the "ct_results" exception and
ignoring it, but obviously I would prefer to get to the root cause of
the problem.


  Oliver


P.S. python-sybase is MUCH faster than ODBC for this large query: ODBC
takes 25 minutes and python-sybase takes 18 seconds!  (The server is in
another country so I guess there is a very high network latency.)=20
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