FreeTDS restrictions on query size?

Hi all,

I'm having an issue with a couple separate queries, and I'm wondering if there's a some sort of restriction on the size of the query. When I break down the queries into their logical parts (as much as I can), they run with no problems.

I've posted one of the queries at the bottom of this message (note that the query I've posted here is just for illustrative purposes--I've sloppily changed all the variable names). I can say this about both queries:


-          They are long: both over 2000 characters

-          They both work when run through FlySpeed query tool in windows

-          They both work when using CentOS 5's stock php-mssql package using "SELECT * FROM OPENQUERY(<link_name>, <my_query>)" --> this connects to a MSSQL 2008 install without encryption.  I'm pretty sure freeTDS isn't being used here, as the server is not in freetds.conf.

I compiled "freetds-0.83.dev.20100706" from source with the following ./configure command:

./configure --prefix=/usr/local/freetds --with-tdsver=8.0 --enable-msdblib --enable-dbmfix --with-gnu-ld --with-gnutls --libdir=/usr/local/freetds/lib

Most queries run successfully, but at least 2 don't. Here are the errors I get when running them with tsql:

Msg 20004, Level 9, State -1, Server OpenClient, Line -1
Read from the server failed

and

Msg 20006, Level 9, State -1, Server OpenClient, Line -1
Write to the server failed
tds_submit_query() failed

I tried the queries on 2 machines: an up-to-date arch install and CentOS 5 -- both with freetds compiled from source as mentioned above.

Finally, the question is, am I missing something? Any reason why this would be happening? What do those error messages mean?

Thanks in advance!

-Jason

Here's one of the queries that doesn't work. It gives the "Msg 20006" / "Write to server failed" error when run through tsql:

Select * From
        (
        Select
            e.Number As studlong,
            e.Number7 As studentno,
            e.fname,
            e.lname,
            p.num AS prognumber,
            es.sessioncode AS session2,
            c.num As courseeno,
            g.num As groupno,
            c.longtitle
        From
            registrations.reg_temp it,
            students.student e,
            students.studentsession es,
            programs.program p,
            courses.course c,
            section.section g
        Where
            it.IDstudentsession = es.IDstudentsession And
            es.IDstudent = e.IDstudent And
            es.IDprogram = p.IDprogram And
            it.IDcourse = g.IDcourse And
            it.IDsection = g.IDsection And
            g.IDcourse = c.IDcourse And
            (e.Number7 = '0000001' And es.sessioncode = '99999')
        ) prereg Left Join
        (
        Select
            Day1.Session,
            Day1.coursee,
            Day1.Section,
            Day1.Day,
            Case
                When
                    Day2.cnt > 1 Then '*'
                    Else ''
            End MoreDays,
            Right('0000' + Convert(VarChar(4),Day1.StartTime), 4) StartTime,
            Right('0000' + Convert(VarChar(4),Day1.EndTime), 4) EndTime,
            Day1.Room
        From
            (
            Select
                q.*
            From
                (
                Select
                    Row_Number()
                    Over
                        (
                        Partition By g.session,
                        c.num,
                        g.num Order By g.session,
                        c.num,
                        g.num,
                        hrt.nday,
                        hrt.starttime,
                        hrt.endtime
                        ) As rowno,
                    g.session Session,
                    c.num coursee,
                    g.num Section,
                    Case hrt.nday
                        When '1' Then 'M'
                        When '2' Then 'T'
                        When '3' Then 'W'
                        When '4' Then 'H'
                        When '5' Then 'F'
                        When '6' Then 'S'
                        When '7' Then 'Su'
                        Else Null End 'Day',
                    hrt.starttime,
                    hrt.endtime,
                    hrl.roomno
                From
                    section.section g,
                    coursees.course c,
                    schedules.section hrg
                Left Outer Join schedules.classtime hrt On hrg.IDclass = hrt.IDclass
                Left Outer Join
                    (
                    Select
                        l.IDclass,
                        el.number
                    From
                        schedules.localclass l,
                        physicalspace.local el
                    Where
                        l.IDlocal = el.IDlocal
                    ) hrl On hrg.IDclass = hrl.IDclass
                Where
                    g.IDsection = hrg.IDsection And
                    g.IDcourse = c.IDcourse
                ) q
            Where q.RowNo = 1
        ) Day1
        Left Join
            (
            Select
                g.session Session,
                c.num coursee,
                g.num Section,
                Count(*) cnt
            From
                section.Groupe g,
                coursees.course c,
                schedules.classsection hrg,
                schedules.classtime hrt
            Where
                g.IDsection = hrg.IDsection And
                g.IDcourse = c.IDcourse And
                hrg.IDRencontre = hrt.IDRencontre
            Group By
                g.session,
                c.num,
                g.num
            ) Day2 On
                Day1.Session = Day2.Session And
                Day1.coursee = Day2.coursee And
                Day1.Section = Day2.Section
        ) sch On
            prereg.session2 = sch.Session And
            prereg.courseeno = sch.coursee And
            prereg.groupno = sch.Section