README file for Informix Database Driver for Perl DBI Version 2015.1101 (2015-11-01)

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

    Be aware that URLs and mailing list addresses can change after a
    product is released but before the next version of the product is made
    available to the public.

    The primary URL for information about Perl, DBI and DBD::Informix is

                       http://dbi.perl.org/

    The primary email address for direct assistance with DBD::Informix is
    dbd.informix@gmail.com, but don't use it until you've read the notes
    below.

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PREREQUISITES

    You need the following five items to build Informix Database Driver for Perl DBI:

    1.  Perl 5.008001 or later.
    2.  DBI 1.607 or later.
    3.  A C compiler that accepts function prototypes (such as GCC).
    4.  Informix ESQL/C 5.20 or later, or Client SDK 3.00 or later.
    5.  A 'stores' database to which you can connect without specifying
        username or password and in which you can create tables.  Ideally,
        the connection should not use shared memory (neither olipcshm nor
        onipcshm), and you should have DBA privileges in the database.

    The basic build steps are:

        perl Makefile.PL
        make
        make test
        make install

    If you are not sure about any of these items or if one of the build
    steps above fails when you run it, you need to read the information
    below.  Read the BUILD AND TEST ENVIRONMENT section when you set your
    environment variables.  If you run into problems during the build or
    test phases, read the section IF YOU HAVE PROBLEMS BUILDING
    DBD::INFORMIX.  Also check the Announce file to see whether there is
    any extra information in there.

    When you have DBD::Informix working *and* installed, use the ItWorks
    Perl script (previously a shell script) to report your successful
    installation.  Be sure to review the output (especially the email
    address it deduces), and send it in an email with the subject
    "DBD::Informix - It Works" to dbd.informix@gmail.com.

TECHNICAL SUPPORT

    For information on Informix Technical Support, please run:

        perldoc DBD::Informix::TechSupport

    If you have not installed DBD::Informix, inspect the file
    DBD/Informix/TechSupport.pm in the source directory.

MAILING LIST SUPPORT FOR DBI AND DBD::INFORMIX

    The mailing list for Perl DBI and DBD::Informix is dbi-users@perl.org.
    For information on how to subscribe to (and unsubscribe from) the
    dbi-users mailing list, send a message to dbi-users-help@perl.org.  You
    could also consider using the news groups comp.lang.perl.modules (for
    Perl and DBI) and comp.databases.informix (for DBD::Informix).

    Before sending anything to any of these, you need a very good excuse
    for not reporting the complete environment via the BugReport script.
    About 95% of problems can be diagnosed by the information this script
    provides - do not assume that you are part of the stray 5%.  The script
    protects the passwords set for testing DBD::Informix.

        perl -Ilib BugReport

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PERL

    If you do not have Perl Version 5.008001 or later installed, you must
    build, test, and install it before you do anything else.  You should
    really use Perl 5.022000 or later.  If at all
    possible, use the C compiler to create shared libraries even if the
    Perl configuration script suggests that you use the 'ld' program
    directly.  People who do not use the C compiler to create the shared
    libraries have often had many problems, and those who use it have
    generally had very few.  Note, there are some platforms, including
    AIX, where you cannot use the C compiler to create shared libraries,
    but that doesn't automatically stop the build from working.
    However, in our experience, you are more likely to run into problems
    on such platforms than on platforms where you can use the C compiler
    to build the shared libraries.  Note that DBD::Informix will witter
    if you do not use the C compiler to link shared libraries.

    Note also that to install DBD::Informix, you must be able to put files
    under the Perl lib directory.  For alternative options, see the
    Notes/nonroot.install file.

    If you are working on NT, you should use the Perl binaries available
    from ActiveState at http://www.activestate.com.  This site also
    provides pre-compiled versions of many Perl modules, including DBI (but
    not DBD::Informix at 2015-08-25).

DBI

    If you do not have DBI version 1.607 or later installed, you should
    build, test, and install it.  Some older versions of DBD::Informix
    allowed you to use older versions of DBI than the version it was
    developed with, but the current versions of DBD::Informix do not.

    Note that "perl -MCPAN -e 'install Bundle::DBI'" gets the latest
    version of DBI and any pre-requisite modules.

C COMPILER

    To build DBD::Informix, the C compiler must accept function prototypes.
    This is not a problem on any computer to which Informix is currently
    ported (though the HP-UX bundled compiler does not accept prototypes at
    all, and the ANSI compiler does not accept them unless told to do so).
    If you have problems, get the GNU C Compiler, Version 5.1.0 or later.
    It is available from http://gcc.gnu.org/ and many mirror sites around
    the world.  You must use the same compiler to build Perl, DBI, and
    DBD::Informix.  The Notes/hpux file contains information about how to
    compile the GNU C Compiler on HP-UX.

ESQL/C OR CLIENT SDK

    You must have a version of IBM Informix Client SDK installed on the
    computer where you wish to compile DBD::Informix.  IBM Informix Connect
    is not sufficient for compiling DBD::Informix.  The Notes/FAQ file
    contains more information about what you need.  ESQL/C Versions 5.00
    and up will probably be OK.  If you do not have ESQL/C, DBD::Informix
    will not work.  You can download IBM Informix Client SDK for free from
    the Informix evaluation web site:

         http://www.ibm.com/software/data/informix/downloads.html

    If you have IBM Informix ODBC drivers available to you, you can
    consider using DBD::ODBC instead.  If you are on Linux, you should
    investigate the software available from the following IBM Informix web
    sites:

                http://www.ibm.com/software/data/informix
           http://www.ibm.com/software/data/developer/informix

    You must also be able to compile, link, and run ESQL/C programs with
    your setup.  Makefile.PL will test that you can do this, but you can
    save time if you ensure this beforehand.  If you cannot compile, link
    and run free-standing ESQL/C programs, you certainly cannot link
    DBD::Informix into Perl.  For help with environment variable settings,
    consult the information below and also the Notes/environment.variables
    file.  (If you are not yet familiar with how to set environment
    variables, be sure to get and read a UNIX primer such as "Learning the
    Unix System, 4th Edition" from O'Reilly, http://www.oreilly.com/, and
    be prepared for a major learning exercise).

    DBD::Informix, Version 1.00 and later, provides limited support for
    user-defined data types (UDTs), treating them as CHAR(255).  To handle
    BLOB and CLOB values, use LOTOFILE() when you fetch the data and
    FILETOBLOB() or FILETOCLOB() when you insert data - see t/t91udts.t for
    examples.  To handle nonblob UDTs that exceed 255 characters in length,
    use server-side cast to lvarchar, as in

        select mycol::lvarchar from mytab;

    Note that the tests that create tables with BLOB or CLOB columns will
    place them in the smart blob space designated by DBD_INFORMIX_SBSPACE,
    and will use the default value 'sbspace' if you do not specify an
    alternative.  If you do not have any smart blob spaces, the tests will
    fail unless you set DBD_INFORMIX_NO_SBSPACE.

    Most versions of ESQL/C that support shared libraries have shared
    linking as the default, which is correct.  Other versions reportedly
    have static linking as the default, which is a nuisance.  The
    Makefile.PL will add the '-shared' flag to the ESQL/C command line to
    try to force shared libraries for ESQL/C Versions 7.20 and up.  If this
    does not work for you or if you are building a static Perl, you will
    need to set the environment variable DBD_INFORMIX_ESQLC_LINKAGE either
    to nothing if your version of ESQL/C does not support the '-shared'
    option or to '-static' to force static linkage.  You could also use
    this environment variable to bootstrap any special ESQL/C compiler
    options into the build process (such as '-thread' if you experiment
    with threaded Perl and threaded ESQL/C); you are advised to set
    '-static' or '-shared' as well.

STORES DATABASE

    Unless you have a 'stores' database that you can connect to without
    specifying a username or password (and in which you can create tables),
    you will need to set various environment variables to tell the build
    and test code for DBD::Informix which database to use for testing and
    exactly how to connect to it.  For more details on the environment
    variables that you can set, see the BUILD AND TEST ENVIRONMENT section.

    You *must* have a fully working Informix environment before you try to
    build and test DBD::Informix.  This means you must have access to at
    least one database.  Ideally, you should have at least RESOURCE level
    privileges (or DBA privileges) on that database; if you don't and
    cannot obtain privileges on a database (perhaps by creating one), then
    set DBD_INFORMIX_NO_RESOURCE=yes in your environment.  Ideally, you
    should be able to create databases too; if you cannot do so, then set
    DBD_INFORMIX_NO_DBCREATE=yes in your environment.  If you do not
    understand what this means, refer to the "Informix Guide to SQL:
    Syntax" manual and read the discussion of the GRANT statement.  You can
    obtain a PDF version of any Informix manual from:

          http://www.ibm.com/software/data/informix/pubs/library

    If you do not have RESOURCE (preferably DBA) privileges on a database,
    consider creating a database called 'stores' for testing.  If you do
    not have DBA privileges, the test t/t55mdata.t may fail but, unless you
    have other problems, you can disregard this failure.

    Note that the tests for DBD::Informix create and drop their own tables.
    Most of the tests use temporary tables.  It does not matter whether the
    test database has database logging, though a logged database allows
    more features to be tested than an unlogged database.  You can use a
    brand new, empty database for testing.  When DBD::Informix creates any
    database object, the name begins with "dbd_ix_".  After running the
    test t/t99clean.t, nothing should remain from the testing.  If you find
    any leftovers, report them to the maintenance team.  DBD::Informix has
    one test that creates a database and then drops it.

SHARED MEMORY CONNECTIONS

    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).  As of version 0.95, the esqltest program will
    report that both connections use shared memory and will allow you to
    proceed after writing a message.  The actual test scripts attempt to
    detect that the two connections both use shared memory connections and
    skip the tests.  However, if you run into problems with shared memory
    connections (for example, error -27000 from the esqltest program),
    read Notes/olipcshm.  If your databases are not on the computer where
    you build DBD::Informix, be sure that you have the necessary privileges
    the necessary privileges to connect to the machine where the databases
    are.  This may be as simple as setting DBD_INFORMIX_USERNAME and
    DBD_INFORMIX_PASSWORD (see BUILD AND TEST ENVIRONMENT) or might require
    you to get your system administrators to set up a login account for you
    on the computer.

BUILD AND TEST ENVIRONMENT

    Be sure to set $INFORMIXDIR even if the software is installed in
    /usr/informix and to have $INFORMIXDIR/bin 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 the directories $INFORMIXDIR/lib and
    $INFORMIXDIR/lib/esql.  With Version 0.95 and above, the absolute
    pathnames of the Informix shared libraries will be built into your
    DBD::Informix library by default, which means that you do not need to
    worry about LD_LIBRARY_PATH, LD_RUN_PATH, SHLIB_PATH, or LIBPATH at
    runtime.  The downside of using absolute pathnames is that if you move
    your Informix software, you also need to rebuild and reinstall
    DBD::Informix.

    If rebuilding DBD::Informix is unacceptable, you need to set the
    environment variable DBD_INFORMIX_RELOCATABLE_INFORMIXDIR to a value
    such as "yes".  The library will be built using relative names to
    identify the Informix shared libraries.  You will be warned that this
    is happening.  Both at test time and at run time, you need to ensure
    that the Informix shared libraries will be found when you run Perl with
    DBD::Informix.  On SVR4 and Linux computers, this means adding these
    directories to LD_LIBRARY_PATH; on HP-UX, the variable is SHLIB_PATH;
    other systems may have other variable names.  Note that web servers, in
    particular, do not propagate most environment variables unless you tell
    them to do so (use SetEnv or PassEnv in Apache).  You need to set
    INFORMIXSERVER correctly unless you are using version 5.x ESQL/C.  You
    may need to set other Informix environment variables too.  Consult the
    Informix documentation and the Notes/environment.variables file.

    The documentation available from 'perldoc DBD::Informix::TestHarness'
    tells you how to set the DBD_INFORMIX_DATABASE, DBD_INFORMIX_USERNAME,
    and DBD_INFORMIX_PASSWORD environment variables for your system.  The
    parallel environment variables with suffix 2 (DBD_INFORMIX_DATABASE2,
    DBD_INFORMIX_USERNAME2, DBD_INFORMIX_PASSWORD2) specify the second test
    database completely independently of the first.  If the defaults are
    OK, you do not have to set any of these six environment variables.  The
    default database is 'stores'; no username and password are supplied if
    none is specified.  If you set the username, you must also set the
    password to have any effect.  Although the testing does as little
    damage as possible, it is not a good idea to use the production
    database for this.  The stores database is a good bet.  Note that these
    variables have significance only when you run the DBD::Informix tests.
    These variables are not used by DBD::Informix itself, only by the code
    in DBD::Informix::TestHarness.  Ideally, you should set the variables
    before you start the build and you should not change them until after
    you complete the testing.  If you do change them, you should check that
    the esqltest program run by 'perl Makefile.PL' still gives your new
    environment a clean bill of health.

    One step in the setup process tests that you have permissions on the
    databases that will be used by the testing.  The step compiles and runs
    a relatively simple ESQL/C program that opens a few databases, creates
    and drops some tables, and exits.  If the test fails, you do you do not
    get a Makefile so you cannot build DBD::Informix.

    Note that if you set the DELIMIDENT environment variable, some tests
    will fail, notably t/t56tabinfo.t and t57tables.t.

    If your database is IDS 9.x or later then you need:
    - either a smart blob space called sbspace,
    - or set the environment variable DBD_INFORMIX_SBSPACE to the name of a
      smart blob space,
    - or set the environment variable DBD_INFORMIX_NO_SBSPACE to 1 to
      indicate that smart blob testing should be omitted.
    - or let the tests deduce whether the smart blob space is available.

BUILDING DBD::INFORMIX WITH BUNDLES

    If you have preconfigured the Perl CPAN module and correctly set up
    your Informix environment, you can install DBD::Informix simply
    DBD::Informix by simply typing:

        perl -MCPAN -e 'install Bundle::DBD::Informix'

    This command gets the latest version of DBI (and its prerequisite
    modules) and the latest version of DBD::Informix, and compiles, tests,
    and install them all completely automatically.  Before doing this, you
    need to be confident that things will work correctly (or that you've
    got good backups of your Perl installation).  On the other hand, it is
    an extremely convenient method of updating your Perl software.

    When you first use the CPAN module, it will ask you many questions,
    including the name of the CPAN site from which to download the
    material, but the CPAN module saves this information for the next time
    and offers you a choice of sites based on continent and

    First consider installing the latest CPAN bundle:

        perl -MCPAN -e 'install Bundle::CPAN'

BUILDING DBD::Informix

    After you install Perl, DBI, and ESQL/C, run:

        perl Makefile.PL

    The script tries to work out how to build the module.  Then run:

        make

    The make command should run without errors and ideally without warnings
    either.  If you get warnings, let us know what they are and how they
    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!  To make changes,
    always try to edit Makefile.PL, which is extensively annotated.  Also
    refer to 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, *let us know* so that we can try
    to make it automatic in a later release.

    Then run:

        make test

    Note that testing DBD::Informix does create some database objects
    (tables, views, synonyms, types, etc).  The database is called
    'dbd_ix_db', and the other object 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_'!  Starting with
    DBD::Informix Version 0.61, the cleanup script t/t99clean.t is run at
    the end of the testing.  It removes the tables, views, synonyms, etc
    and so on that DBD::Informix might have created.  Running it manually
    ("test.one.sh t/t99clean.t") also cleans up the database objects
    created by testing DBD::Informix.  The tests should be 100% clean if
    you run the cleanup script, but if you don't run that, the tests can
    leave the odd table or stored procedure (or user-defined data types and
    so on) in the database.

    Additionally, for a really thorough scrutiny of DBD::Informix, you need
    to test it with at least three different databases: one created with
    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

    Different tests will be skipped depending on the version of ESQL/C, the
    version of the database, and the logging modes of the databases you are
    connecting to.

    If you are concerned about both OnLine and SE, then the connection
    tests will use two different databases if you set the environment
    variable DBD_INFORMIX_DATABASE2 (and possibly DBD_INFORMIX_USERNAME2
    and DBD_INFORMIX_PASSWORD2).  You can also use one SE database and one
    OnLine database.  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 use the makefile of the new version to install.  It is
    important to use the correct old or new makefile because the installed
    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,
    fill your disk completely.

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

        make perl
        make test_static

    Please consult the Notes/Working.Versions file for information about
    known working versions of the software (and specific problem versions).
    If you are using a combination of versions which is different from any
    previously recorded, please send me (dbd.informix@gmail.com) the details
    for your new, successful port.

    If you run into major problems even getting the esqltest program to
    compile, you can try to compile the esqlbasic.ec program with a plain
    ESQL/C command:

        esql -o esqlbasic esqlbasic.ec

    If even this command will not compile, concentrate on fixing your ESQL/C
    ESQL/C environment before doing anything else with DBD::Informix.  If
    it compiles but does not run, then you need to ensure that you fix the
    Informix environment so that you can access databases.  Once this test
    both compiles and runs, you will probably be able to compile and test
    DBD::Informix.

    To suppress the esqltest code in Makefile.PL, you can set
    DBD_INFORMIX_NO_ESQLTEST=yes in your environment before you run 'perl
    Makefile.PL'.  If you do that, however, no problem reports will be
    accepted; the esqltest code is critical to ensuring that DBD::Informix
    has some chance of compiling successfully.

    You can see how the esqltest code is compiled if you set
    DBD_INFORMIX_DEBUG_ESQLTEST=yes in your environment before you run
    'perl Makefile.PL'.

    For more information on environment variables for both DBD:Informix and
    Informix, see the Notes/environment.variables file.

KNOWN PROBLEMS:

    * If you run into problems with spurious options being passed to the
      compiler, you can set $DBD_INFORMIX_ESQLCC_REMOVE_OPTIONS_REGEX to
      remove those options.  For example, if the -KPIC option is being
      passed to GCC, set the value of the environment variable to
      '^-KPIC$'.

    * If you run into problems with spurious options being passed to the
      linker, you can set $DBD_INFORMIX_ESQLLD_REMOVE_OPTIONS_REGEX to
      remove those options.  For example, if the -lc, -laio and -lelf
      libraries cause trouble (or are simply redundant), set the value of
      the environment variable to '^-l(c|aio|elf)$'.

    * If you run into problems with esqlcc or esqlld, set either
      DBD_INFORMIX_DEBUG_ESQLLD or DBD_INFORMIX_DEBUG_ESQLCC (or both) to a
      non-zero, non-empty value such as 'yes' and rerun the build.

IF YOU HAVE PROBLEMS BUILDING DBD::INFORMIX

    Read all this README file (there is a lot of information in here), and
    the Notes/bug.reports file, which describes what to do and where to
    send the failure report.  Please ensure that any email message has
    DBD::Informix in the subject line -- thanks!

IF YOU HAVE PROBLEMS USING DBD::INFORMIX

    If you have a problem with your own code and all the DBD::Informix
    tests succeed, in your initial message give the version information
    (see the Notes/bug.reports file), 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.  Be sure
    to use DBD::Informix in the subject line of any email -- thanks!

    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'.  If you are using
       SE, please mention that.
    2. Use temporary tables rather than permanent ones.
    3. Load just enough data to show the problem.
    4. Test every statement that uses a DBI function for success, or
       connect using a variant on:
          $dbh = DBI->connect('dbi:Informix:stores','','',{RaiseError=>1});
    5. Clearly indicate when it fails.
    6. Clearly indicate when the test succeeds.
    7. The test script should not use DBI->install_driver().

    If your test is failing with a core dump, the stack trace may be useful
    if it lists function names.  The stack trace is not useful if it does
    not list them.

    The tests which come with DBD::Informix show a variety of ways of using
    DBD::Informix.  If you need to see how something is used, consider
    looking at the test code, including DBD::Informix::TestHarness.

    The examples subdirectory contains some simple examples of DBI scripts
    for examples sub-directory.  Read the examples/README file for more
    details.

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REMEMBER IT IS SUPPOSED TO BE FUN!

Jonathan Leffler (jleffler@us.ibm.com)

@(#)$Id: README,v 2015.3 2015/08/27 02:28:24 jleffler Exp $

---------------------------------------------------------------------------

Copyright 1994    Tim Bunce <Tim.Bunce@ig.co.uk>
Copyright 1994-96 Alligator Descartes <descarte@arcana.co.uk>
Copyright 1996-98 Jonathan Leffler <johnl@informix.com>
Copyright 1998    Jonathan Leffler <j.leffler@acm.org>
Copyright 1998-99 Jonathan Leffler <jleffler@informix.com>
Copyright 2000-01 Informix Software Inc
Copyright 2002    IBM
Copyright 2003-13 Jonathan Leffler <jleffler@us.ibm.com>
Copyright 2013    Jonathan Leffler <jleffler@google.com>
Copyright 2015    Jonathan Leffler <jleffler@us.ibm.com>