README for DBD::Informix -- an Informix interface for Perl 5 using DBI.

   Portions Copyright (c) 1994,1995,1996  Alligator Descartes
   Portions Copyright (c) 1996,1997       Jonathan Leffler

   You may distribute under the terms of either the GNU General Public
   License or the Artistic License, as specified in the Perl README file.

-- The following is a standard warning for all DBI and DBD::* software --
       WARNING: THIS IS ALPHA SOFTWARE. IT IS POSSIBLY UNRELIABLE!

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PREREQUISITES

    If you do not have Perl version 5.003 or later, then build, test and
    install it before doing anything else!  And please ensure that you
    compile it with whatever options are necessary to get __STDC__ defined.

    If you do not have DBI version 0.85 or later installed, then build,
    test and install it.  Note that previous versions of DBD::Informix
    allowed you to use older versions of DBI than the version it was built
    with.  This policy changed with DBD::Informix v0.54.  In addition, the
    code in DBD::Informix v0.56 requires bug fixes present in DBI 0.85
    which were not in DBI 0.84.

    To build DBD::Informix, the C compiler must accept function prototypes.
    This is not a problem on any machine to which Informix is currently
    ported (though the HP-UX compiler does not accept prototypes unless
    told to do so).

    You must have a version of Informix-ESQL/C available to you.  You
    should read the Informix.Licence file for information about what you
    need.  At the moment, ESQL/C Versions 4.0x or 4.1x are not supported,
    nor are any earlier versions.  ESQL/C Versions 5.00 upwards should be
    OK.

    *** BEWARE ***

    DBD::Informix version 0.56 has been tested on Informix-Universal Server
    version 9.11.UC1 (on a Sparc 20 running Solaris 2.5.1).  Where the IUS
    database uses the same types as were available in earlier versions of
    Informix products, there doesn't seem to be any problem.  However, it
    is known to fail badly (usually with an assert firing and a core dump,
    but also with error -402 'Address of a host variable is NULL') if it
    encounters one of the IUS-specific data types.

    The IUS SysProcedures table in the system catalog has a ParamTypes
    column which is of the type RtnParamTypes, and therefore DBD::Informix
    will not work if you try to select all the columns from this table.
    There are probably other columns in the system catalog for which this
    is true.  And there may be other tables which won't work for the same
    reason.

    *** YOU WERE WARNED ***

    DBD::Informix has never been tested with a version 8.x (OnLine XPS)
    version of ESQL/C and database.

    *** YOU WERE WARNED ABOUT THIS TOO ***

    You need to have a fully working Informix environment before you try to
    build and test DBD::Informix.  This means you need to have access to at
    least one database where you have at least RESOURCE level privileges.
    (If you don't understand what this means, read the "Informix Guide to
    SQL: Syntax" manual, and especially the GRANT section).  If you don't
    have DBA privileges on any databases, you should consider creating the
    'stores' database using the dbaccessdemoN program (where N is a version
    number, such as 7) which comes with your server.  The multiple
    connection tests use two databases for preference (though the tests
    will use the same database twice if you do not specify two separate
    databases), and the test will fail if you use olipcshm or onipcshm
    (shared memory) connections to both databases.  If you run into
    problems with shared memory connections (for example, error -27000 from
    the esqltest program), then read README.olipcshm.  If your databases
    are not on the machine where you are building DBD::Informix, you will
    need to ensure that you have the necessary privileges to connect to the
    machine where the databases are.  This may be as simple as setting
    DBD_INFORMIX_PASSWORD (see below); it may be require you to get your
    systems administrators to set you up with a login account on the
    machine.

    Please ensure that you have $INFORMIXDIR set unless the software is
    installed in /usr/informix, and that $INFORMIXDIR/bin is on your PATH.
    The build no longer works unless these environment variables are set.
    Also, if you are using ESQL/C version 6.x or later, you may be using
    ESQL/C shared libraries which are found in $INFORMIXDIR/lib and
    $INFORMIXDIR/lib/esql.  You need to ensure that these will be found
    when you run Perl with DBD::Informix.  On SVR4 machines, this means
    adding these directories to LD_LIBRARY_PATH; on HP-UX, the variable is
    SHLIB_PATH; other systems may have other variable names.  You need to
    set INFORMIXSERVER correctly if you are using version 6.0x or later.
    You may need to set other environment variables too -- consult the
    Informix manuals for more information.

    You should take a look at the documentation in InformixTest.pm, and set
    the DBD_INFORMIX_DATABASE, DBD_INFORMIX_USERNAME, DBD_INFORMIX_PASSWORD
    and DBD_INFORMIX_SERVER environment variables as appropriate for your
    system.  Although the testing does as little damage as possible, it is
    not a good idea to use your prize database for this.  The stores
    database is a good bet (unless you are using an old version of Fourgen
    software and it is using the stores database for its data dictionary).
    Note that these variables only have significance when running the
    DBD::Informix tests.  They are not used by DBD::Informix itself, only
    by DBD::InformixTest.

    One step in the setup process tests that you have permissions on the
    databases which will be used by the testing.  It does this by compiling
    and running a relatively simple ESQL/C program which simply opens a few
    databases, creates and drops some tables, and exits.

BUILDING DBD::Informix

    When Perl, DBI and ESQL/C are all installed do:

        perl Makefile.PL

    The script will attempt to work out what it needs to build the module.
    Then do:

        make

    This should complete without errors, and ideally without warnings
    either.  If you get warnings, I'm interested to know what they are and
    how they could be fixed generically.  If it fails horribly, see below.

    Do NOT hand edit the generated Makefile unless you are completely sure
    you understand the implications (and are willing to make those changes
    manually every time the Makefile is regenerated)!  Always try to make
    changes by editing Makefile.PL, which is extensively annotated.  You
    should also read the section on ExtUtils::MakeMaker in the 2nd Edition
    of 'Programming Perl'.

    You should never need to make any changes to the generated Makefile,
    nor to Makefile.PL.  If you do *please* let me know so that I can try
    to make it automatic in a later release.

    Then run:

        make test

    Note that testing DBD::Informix does create some tables and databases.
    The database is normally called 'dbd_ix_db', and the table names start
    with 'dbd_ix_'.  Some of the tables are permanent; most are temporary.
    The tests are designed to work whether the tables and database are
    present when the tests start or not; that means they get dropped.  Do
    not run the tests if you have precious tables or databases that begin
    'dbd_ix_'!

    On the reference system (Sun Sparc 20 running Solaris 2.5.1, compiling
    with GCC 2.7.0 or SUNWspro SC4.0.1, using either Perl 5.003 or 5.004),
    all the tests pass when DBD::Informix is built with ESQL/C versions
    5.08.UD1, 6.00.UE1, 7.13.UC1 7.23.UC1 and 9.11.UC1.

    It is a good idea to run:

        make test TEST_VERBOSE=1

    You should inspect the results as not every test compares the actual
    data returned with the data that should be returned (though many of
    them do check the data which is returned).  Note that the blob tests
    pass on SE, because the test scripts detect that the engine is SE and
    do not try to test blob handling.

    Additionally, for a really thorough scrutiny of DBD::Informix, you need
    to test with at least 3 different databases: one created MODE ANSI, one
    created with a transaction log but not MODE ANSI, and one created
    without any transaction logs at all.

        DBD_INFORMIX_DATABASE=mode_ansi make test
        DBD_INFORMIX_DATABASE=logged    make test
        DBD_INFORMIX_DATABASE=unlogged  make test

    If you are concerned about both OnLine and SE, then you need these
    databases for both environments.  Also note that the multiple
    connection tests will use two different databases if you set the
    environment variable DBD_INFORMIX_DATABASE2, but the tests assume that
    you don't need to specify the user and password.  This could be fixed,
    but hasn't happened yet.  You can use one SE and one OnLine database
    for the multiple connection testing.  You can also test with different
    server versions (eg using 7.2x ESQL/C to connect to a 5.0x OnLine) if
    you have the software available.

    Once you are satisfied that DBD::Informix is working correctly, you
    should install it:

        make install

    If you ever need to remove it, possibly as a preamble to installing a
    new version, you should use the old version's makefile and run:

        make uninstall

    You can then install using the new version's makefile.  It is important
    to use the correct (old or new) makefiles because the installed files
    may be different, and if some file is made obsolete by the new version
    (is not used by the new version), its makefile will not uninstall the
    obsolete file; over time and multiple versions, this could, eventually,
    lead to 'coronary thrombosis' on your disk drive -- or disk full.

    If you run into problems which suggest that the ESQL/C you have won't
    work as dynamically loaded libraries (eg on HP-UX or SCO), then you
    should create a statically linked version of Perl with DBD::Informix
    linked to it.  Use:

        make perl
        make test_static

KNOWN PROBLEMS:

    * DBD::Informix uses SQL DESCRIPTORS which are not part of ESQL/C
      Version 4.0x or 4.1x.  It also uses string-named cursors and
      statements, which are likewise not supported in 4.0x or 4.1x (or
      earlier) versions.

    * Some problems have been encountered on HP-UX 9.x when building shared
      libraries using 5.0x and 6.0x ESQL/C.  This seems to be because the
      HP-UX compilers and loader do not accept code not compiled for shared
      libraries inside a shared library.  Help (or reassurance) is needed on
      this.

    * Some problems have been encountered on SCO which seems to be related
      to the equivalent of LD_LIBRARY_PATH on System V Release 4 machines.
      Again, help or reassurance is needed on this.

    * If you are using GCC to compile the software on Solaris, ensure that
      you also use GCC to build the shared libraries, rather than trying to
      use 'ld'.  If you use ld instead, you are likely to run into problems
      with an undefined symbol __eprintf.  If you have this problem, the
      fix is usually to reconfigure (and therefore rebuild) Perl to use GCC
      to create the shared libraries.  It is not clear why using GCC gives
      this problem.  Also, do not use the GNU assembler or loader with GCC
      on Solaris; they don't work properly with shared libraries.

IF YOU HAVE PROBLEMS BUILDING DBD::INFORMIX

Firstly, check the Frequently Asked Questions, Known Bugs and any other
pertinent documents at:

    http://www.hermetica.com/technologia/DBI

If this does *not* resolve your problem, please post the details of your
problem to dbi-users@fugue.com and CC them to me at johnl@informix.com.

There are 4 types of failures which you might encounter:
    A.  A configuration failure (perl Makefile.PL does not work)
    B.  A build failure (the Makefile was generated but there were problems
        during the build proper so that no test worked at all)
    C.  A general test failure (although the build appeared OK, every
        single test fails, or almost all of them fail).
    D.  A selective test failure (the build appeared OK and most of the
        tests pass, but a few (say 1 to 5) of them fail).
Please classify your problem and follow the relevant steps below.

Please include:

1. A log of a complete build:

    # Before doing anything, please either re-extract the source from the
    # compressed tar file you retrieved from CPAN into an empty directory
    # or make sure that the build area is really clean:
    [ -f Makefile ] && make realclean
    rm -f esql esqlvrsn.h

    # Send this output for all failure types (A, B, C, D)
    perl Makefile.PL

    # Send this output for failure types B, C, D.
    make

    # Send this output for failure types C, D
    # If the output is more than about 30 lines, then just send the first
    # 30 lines or so of the output -- anything more is unlikely to give any
    # extra information.
    make test

    # Send this output for failure types C, D
    # Then, taking the first test which fails (typically basic00.t) send
    # the output from:
    test.one t/basic00.t

    # Send this output for failure type D
    # If the failing tests are failing in distinctly different ways
    # (different error messages, or one is a core dump, or ...) then send
    # the test output for each of the different outputs, but do not send
    # more than 5 sets of test results unless requested to do so.
    test.one t/dbase.t

    If you use a Bourne or Korn Shell (or any work-alikes), you can also
    use the following command to get a lot more debug information, but
    don't send this unless asked to do so:

    PERL_DBI_DEBUG=2 test.one t/basic00.t

    Use this to verify that the problems you are reporting as different for
    failure type D really are different, but still don't send the output
    unless asked to do so.

2. A complete, sorted dump of your environment:

    env | sort

3. Full details of which version of Informix-ESQL/C and Perl you're using.
   The output of "perl -V" gives the Perl information; running "esql -V"
   gives the Informix-ESQL/C information.

5. If you get a core dump, try to include a stack trace from it.  If the
   stack trace mentions XS_DynaLoader_dl_load_file then rerun make test
   after setting the environment variable PERL_DL_DEBUG to 2.  Similarly,
   get the Devel::CoreStack module and use it.  Do not send a stack trace
   if it does not contain function names.

6. Please don't post problems to comp.lang.perl.misc or perl5-porters.

7. If you are not currently subscribed to the mailing list please subscribe
   via http://www.fugue.com/dbi.  If you do not have WWW access, then send
   email to dbi-request@fugue.com.  There are 3 mailing lists:
   dbi-announce@fugue.com, dbi-users@fugue.com and dbi-dev@fugue.com.

IF YOU HAVE PROBLEMS USING DBD::INFORMIX

If your problem is with your own code and the DBD::Informix tests all pass,
then the initial message should give the version information (see point 3
above, plus the version of the Informix database engine you are using), a
description of the problem, a minimal test script, and the results of
running the test script on your machine (along with an explanation of why
the result is wrong -- it may not be obvious to me -- and what the correct
result should be).

The minimal test script should preferably:

(1) Use the stores database, with empty username and password fields.  If
    the test needs a particular type of database (eg with transactions) to
    demonstrate the problem, alternative convenient names are 'logged',
    'unlogged' and 'mode_ansi'.
(2) Use temporary tables rather than permanent ones.
(3) Load just enough data to show the problem.
(4) Test every statement using DBI functions for success.
(5) Clearly indicate when it fails.
(6) Clearly indicate when it passes.
(7) It had better not use DBI->install_driver() without an extremely good
    reason, and I can't immediately think of a reason which would be good
    enough.

If your test is failing with a core dump, the stack trace for it is useful
if it lists function names -- it is not useful if it does not.

Regards,
Jonathan Leffler (johnl@informix.com)

@(#)$Id: README,v 56.6 1997/07/13 01:18:24 johnl Exp $

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NOTE: This document is derived from the DBD::Oracle README.  Many of the
points made in that will apply to DBD::Informix too.

Original document: (c) Tim Bunce <Tim.Bunce@ig.co.uk>
Amendments 1:      (c) Alligator Descartes <descarte@hermetica.com>
Amendments 2:      (c) Jonathan Leffler <johnl@informix.com>
