                                   BerkeleyDB

                                  Version 0.20

                                  2nd Sept 2002

	Copyright (c) 1997-2002 Paul Marquess. All rights reserved. This
	program is free software; you can redistribute it and/or modify
	it under the same terms as Perl itself.


DESCRIPTION
-----------

BerkeleyDB is a module which allows Perl programs to make use of the
facilities provided by Berkeley DB version 2 or greater. (Note: if
you want to use version 1 of Berkeley DB with Perl you need the DB_File
module).

Berkeley DB is a C library which provides a consistent interface to a
number of database formats. BerkeleyDB provides an interface to all
four of the database types (hash, btree, queue and recno) currently
supported by Berkeley DB.

For further details see the documentation in the file BerkeleyDB.pod.

PREREQUISITES
-------------

Before you can build BerkeleyDB you need to have the following
installed on your system:

    * Perl 5.004_04 or greater.

    * Berkeley DB Version 2.6.4 or greater

      The official web site for Berkeley DB is http://www.sleepycat.com

      The latest version of Berkeley DB is always available there. It
      is recommended that you use the most recent version available at
      the Sleepycat site.

      The one exception to this advice is where you want to use BerkeleyDB
      to access database files created by a third-party application,
      like Sendmail. In these cases you must build BerkeleyDB with a
      compatible version of Berkeley DB.


BUILDING THE MODULE
-------------------

Assuming you have met all the prerequisites, building the module should
be relatively straightforward.

Step 1 : If you are running Solaris 2.5, 2.7 or HP-UX 10 read either
         the Solaris Notes or HP-UX Notes sections below.
	 If you are running Linux please read the Linux Notes section
         before proceeding.


Step 2 : Edit the file config.in to suit you local installation.
         Instructions are given in the file.

Step 3 : Build and test the module using this sequence of commands:

             perl Makefile.PL
             make
             make test

INSTALLATION
------------

    make install

TROUBLESHOOTING
===============

Here are some of the problems that people encounter when building BerkeleyDB.

Missing db.h or libdb.a
-----------------------

If you get an error like this:

  cc -c -I./libraries/ -Dbool=char -DHAS_BOOL -I/usr/local/include -O2
  -DVERSION=\"0.07\" -DXS_VERSION=\"0.07\" -fpic
  -I/usr/local/lib/perl5/5.00503/i586-linux/CORE  BerkeleyDB.c
  BerkeleyDB.xs:52: db.h: No such file or directory

or this:

  cc -c -I./libraries/2.7.5 -Dbool=char -DHAS_BOOL -I/usr/local/include -O2
  -DVERSION=\"0.07\" -DXS_VERSION=\"0.07\" -fpic
  -I/usr/local/lib/perl5/5.00503/i586-linux/CORE  BerkeleyDB.c
  LD_RUN_PATH="/lib" cc -o blib/arch/auto/BerkeleyDB/BerkeleyDB.so  -shared
  -L/usr/local/lib BerkeleyDB.o
  -L/home/paul/perl/ext/BerkDB/BerkeleyDB/libraries -ldb
  ld: cannot open -ldb: No such file or directory

This symptom can imply:

 1. You don't have Berkeley DB installed on your system at all.
    Solution: get & install Berkeley DB.

 2. You do have Berkeley DB installed, but it isn't in a standard place.
    Solution: Edit config.in and set the LIB and INCLUDE variables to point
              to the directories where libdb.a and db.h are installed.

#error db.h is not for Berkeley DB at all.
------------------------------------------

If you get the error above when building this module it means that there
is a file called "db.h" on your system that isn't the one that comes
with Berkeley DB.

Options:

 1. You don't have Berkeley DB installed on your system at all.
    Solution: get & install Berkeley DB.

 2. Edit config.in and make sure the INCLUDE variable points to the
    directory where the Berkeley DB file db.h is installed.

 3. If option 2 doesn't work, try tempoarily renaming the db.h file
    that is causing the error.

#error db.h is for Berkeley DB 1.x - need at least Berkeley DB 2.6.4
--------------------------------------------------------------------

The error above will occur if there is a copy of the Berkeley DB 1.x
file db.h on your system.

This error will happen when 

  1. you only have Berkeley DB version 1 on your system.
     Solution: get & install a newer version of Berkeley DB.

  2. you have both version 1 and a later version of Berkeley DB
     installed on your system. When building BerkeleyDB it attempts to
     use the db.h for Berkeley DB version 1.
     Solution: Edit config.in and set the LIB and INCLUDE variables
               to point to the directories where libdb.a and db.h are
               installed.


#error db.h is for Berkeley DB 2.0-2.5 - need at least Berkeley DB 2.6.4
------------------------------------------------------------------------

The error above will occur if there is a copy of the the file db.h for
Berkeley DB 2.0 to 2.5 on your system.

This symptom can imply:

 1. You don't have a new enough version of Berkeley DB.
    Solution: get & install a newer version of Berkeley DB.

 2. You have the correct version of Berkeley DB installed, but it isn't
    in a standard place.
    Solution: Edit config.in and set the LIB and INCLUDE variables
              to point to the directories where libdb.a and db.h are
              installed.

Undefined Symbol: txn_stat 
--------------------------

BerkeleyDB seems to have built correctly, but you get an error like this
when you run the test harness:

  $ make test
  PERL_DL_NONLAZY=1 /home/paul/perl/install/bin/perl5.00503
  -Iblib/arch -Iblib/lib -I/usr/local/lib/perl5/5.00503/i586-linux
  -I/usr/local/lib/perl5/5.00503 -e 'use Test::Harness qw(&runtests $verbose);
  $verbose=0; runtests @ARGV;' t/*.t
  t/btree.............Can't load 'blib/arch/auto/BerkeleyDB/BerkeleyDB.so' for
  module BerkeleyDB: blib/arch/auto/BerkeleyDB/BerkeleyDB.so:
  undefined symbol: txn_stat
  at /usr/local/lib/perl5/5.00503/i586-linux/DynaLoader.pm line 169.
  ...

This error usually happens when you have both version 1 and a newer version
of Berkeley DB installed on your system. BerkeleyDB attempts
to build using the db.h for Berkeley DB version 2/3/4 and the version 1
library. Unfortunately the two versions aren't compatible with each
other. BerkeleyDB can only be built with Berkeley DB version 2, 3 or 4.

Solution: Setting the LIB & INCLUDE variables in config.in to point to the
          correct directories can sometimes be enough to fix this
          problem. If that doesn't work the easiest way to fix the
          problem is to either delete or temporarily rename the copies
          of db.h and libdb.a that you don't want BerkeleyDB to use.

Undefined Symbol: db_appinit 
----------------------------

BerkeleyDB seems to have built correctly, but you get an error like this
when you run the test harness:

  $ make test
  PERL_DL_NONLAZY=1 /home/paul/perl/install/bin/perl5.00561 -Iblib/arch 
  -Iblib/lib -I/home/paul/perl/install/5.005_61/lib/5.00561/i586-linux 
  -I/home/paul/perl/install/5.005_61/lib/5.00561 -e 'use Test::Harness 
  qw(&runtests $verbose); $verbose=0; runtests @ARGV;' t/*.t
  t/btree.............Can't load 'blib/arch/auto/BerkeleyDB/BerkeleyDB.so' for 
  module BerkeleyDB: blib/arch/auto/BerkeleyDB/BerkeleyDB.so: 
  undefined symbol: db_appinit 
  at /home/paul/perl/install/5.005_61/lib/5.00561/i586-linux/DynaLoader.pm 
  ...


This error usually happens when you have both version 2 and version
3 of Berkeley DB installed on your system and BerkeleyDB attempts
to build using the db.h for Berkeley DB version 2 and the version 3
library. Unfortunately the two versions aren't compatible with each
other. 

Solution: Setting the LIB & INCLUDE variables in config.in to point to the
          correct directories can sometimes be enough to fix this
          problem. If that doesn't work the easiest way to fix the
          problem is to either delete or temporarily rename the copies
          of db.h and libdb.a that you don't want BerkeleyDB to use.

Undefined Symbol: db_create
---------------------------

BerkeleyDB seems to have built correctly, but you get an error like this
when you run the test harness:

  $ make test   
  PERL_DL_NONLAZY=1 /home/paul/perl/install/bin/perl5.00561 -Iblib/arch 
  -Iblib/lib -I/home/paul/perl/install/5.005_61/lib/5.00561/i586-linux 
  -I/home/paul/perl/install/5.005_61/lib/5.00561 -e 'use Test::Harness 
  qw(&runtests $verbose); $verbose=0; runtests @ARGV;' t/*.t
  t/btree.............Can't load 'blib/arch/auto/BerkeleyDB/BerkeleyDB.so' for 
  module BerkeleyDB: blib/arch/auto/BerkeleyDB/BerkeleyDB.so: 
  undefined symbol: db_create 
  at /home/paul/perl/install/5.005_61/lib/5.00561/i586-linux/DynaLoader.pm 
  ...

This error usually happens when you have both version 2 and version
3 of Berkeley DB installed on your system and BerkeleyDB attempts
to build using the db.h for Berkeley DB version 3 and the version 2
library. Unfortunately the two versions aren't compatible with each
other. 

Solution: Setting the LIB & INCLUDE variables in config.in to point to the
          correct directories can sometimes be enough to fix this
          problem. If that doesn't work the easiest way to fix the
          problem is to either delete or temporarily rename the copies
          of db.h and libdb.a that you don't want BerkeleyDB to use.


Incompatible versions of db.h and libdb
---------------------------------------

BerkeleyDB seems to have built correctly, but you get an error like this
when you run the test harness:

  $ make test
  PERL_DL_NONLAZY=1 /home/paul/perl/install/bin/perl5.00503
  -Iblib/arch -Iblib/lib -I/usr/local/lib/perl5/5.00503/i586-linux
  -I/usr/local/lib/perl5/5.00503 -e 'use Test::Harness qw(&runtests $verbose);
  $verbose=0; runtests @ARGV;' t/*.t
  t/btree.............
  BerkeleyDB needs compatible versions of libdb & db.h
          you have db.h version 2.6.4 and libdb version 2.7.5
  BEGIN failed--compilation aborted at t/btree.t line 25.
  dubious
        Test returned status 255 (wstat 65280, 0xff00)
  ...	

Another variation on the theme of having two versions of Berkeley DB on
your system. 

Solution: Setting the LIB & INCLUDE variables in config.in to point to the
          correct directories can sometimes be enough to fix this
          problem. If that doesn't work the easiest way to fix the
          problem is to either delete or temporarily rename the copies
          of db.h and libdb.a that you don't want BerkeleyDB to use.
	  If you are running Linux, please read the Linux Notes section below.


Linux Notes
-----------

Newer versions of Linux (e.g. RedHat 6, SuSe 6) ship with a C library
that has version 2.x of Berkeley DB linked into it. This makes it
difficult to build this module with anything other than the version of
Berkeley DB that shipped with your Linux release. If you do try to use
a different version of Berkeley DB you will most likely get the error
described in the "Incompatible versions of db.h and libdb" section of
this file.

To make matters worse, prior to Perl 5.6.1, the perl binary itself
*always* included the Berkeley DB library.

If you want to use a newer version of Berkeley DB with this module, the
easiest solution is to use Perl 5.6.1 (or better) and Berkeley DB 3.x
(or better).

There are two approaches you can use to get older versions of Perl to
work with specific versions of Berkeley DB. Both have their advantages
and disadvantages.

The first approach will only work when you want to build a version of
Perl older than 5.6.1 along with Berkeley DB 3.x. If you want to use
Berkeley DB 2.x, you must use the next approach. This approach involves
rebuilding your existing version of Perl after applying an unofficial
patch. The "patches" directory in the this module's source distribution
contains a number of patch files. There is one patch file for every
stable version of Perl since 5.004. Apply the appropriate patch to your
Perl source tree before re-building and installing Perl from scratch.
For example, assuming you are in the top-level source directory for
Perl 5.6.0, the command below will apply the necessary patch. Remember
to replace the path shown below with one that points to this module's
patches directory.

    patch -p1 -N </path/to/BerkeleyDB/patches/5.6.0

Now rebuild & install perl. You should now have a perl binary that can
be used to build this module. Follow the instructions in "BUILDING THE
MODULE", remembering to set the INCLUDE and LIB variables in config.in.


The second approach will work with Berkeley DB 2.x or better.
Start by building Berkeley DB as a shared library. This is from
the Berkeley DB build instructions:

    Building Shared Libraries for the GNU GCC compiler

    If you're using gcc and there's no better shared library example for
    your architecture, the following shared library build procedure will
    probably work.

    Add the -fpic option to the CFLAGS value in the Makefile.

    Rebuild all of your .o files. This will create a Berkeley DB library
    that contains .o files with PIC code. To build the shared library,
    then take the following steps in the library build directory:

    % mkdir tmp
    % cd tmp
    % ar xv ../libdb.a
    % gcc -shared -o libdb.so *.o
    % mv libdb.so ..
    % cd ..
    % rm -rf tmp

    Note, you may have to change the gcc line depending on the
    requirements of your system.

    The file libdb.so is your shared library

Once you have built libdb.so, you will need to store it somewhere safe.

    cp libdb.so /usr/local/BerkeleyDB/lib

If you now set the LD_PRELOAD environment variable to point to this
shared library, Perl will use it instead of the version of Berkeley DB
that shipped with your Linux distribution.

    export LD_PRELOAD=/usr/local/BerkeleyDB/lib/libdb.so

Finally follow the instructions in "BUILDING THE MODULE" to build,
test and install this module. Don't forget to set the INCLUDE and LIB
variables in config.in.

Remember, you will need to have the LD_PRELOAD variable set anytime you
want to use Perl with Berkeley DB. Also note that if you have LD_PRELOAD
permanently set it will affect ALL commands you execute. This may be a
problem if you run any commands that access a database created by the
version of Berkeley DB that shipped with your Linux distribution.



Solaris 2.5 Notes
-----------------

If you are running Solaris 2.5, and you get this error when you run the
BerkeleyDB test harness:

    libc internal error: _rmutex_unlock: rmutex not held.

you probably need to install a Sun patch. It has been reported that
Sun patch 103187-25 (or later revisions) fixes this problem.

To find out if you have the patch installed, the command "showrev -p"
will display the patches that are currently installed on your system.

Solaris 2.7 Notes
-----------------

If you are running Solaris 2.7 and all the tests in the test harness
generate a core dump, try applying Sun patch 106980-09 (or better).

To find out if you have the patch installed, the command "showrev -p"
will display the patches that are currently installed on your system.


HP-UX Notes
-----------

Some people running HP-UX 10 have reported getting an error like this
when building this module with the native HP-UX compiler.

    ld: (Warning) At least one PA 2.0 object file (BerkeleyDB.o) was detected.
    The linked output may not run on a PA 1.x system.
    ld: Invalid loader fixup for symbol "$000000A5".

If this is the case for you, Berkeley DB needs to be recompiled with
the +z or +Z option and the resulting library placed in a .sl file. The
following steps should do the trick:

  1: Configure the Berkeley DB distribution with the +z or +Z C compiler
     flag:

        env "CFLAGS=+z" ../dist/configure ...

  2: Edit the Berkeley DB Makefile and change:

        "libdb= libdb.a" to "libdb= libdb.sl".

  3: Build and install the Berkeley DB distribution as usual.



FEEDBACK
--------

How to report a problem with BerkeleyDB.

To help me help you, I need of the following information:

 1. The version of Perl and the operating system name and version you
    are running. The complete output from running "perl -V" will tell
    me all I need to know.  
    If your perl does not understand the "-V" option is too old.
    BerkeleyDB needs Perl version 5.004_04 or better.

 2. The version of BerkeleyDB you have. If you have successfully
    installed BerkeleyDB, this one-liner will tell you:

       perl -MBerkeleyDB -e 'print qq{BerkeleyDB ver $BerkeleyDB::VERSION\n}'

    If you haven't installed BerkeleyDB then search BerkeleyDB.pm for a
    line like this:

      $VERSION = "1.20" ;

 3. The version of Berkeley DB you have installed. If you have
    successfully installed BerkeleyDB, this one-liner will tell you:

        perl -MBerkeleyDB -e 'print BerkeleyDB::DB_VERSION_STRING.qq{\n}'

    If you haven't installed BerkeleyDB then search db.h for a line
    like this:

      #define DB_VERSION_STRING

 4. If you are having problems building BerkeleyDB, send me a complete
    log of what happened.

 5. Now the difficult one. If you think you have found a bug in
    BerkeleyDB and you want me to fix it, you will *greatly* enhance
    the chances of me being able to track it down by sending me a small
    self-contained Perl script that illustrates the problem you are
    encountering. Include a summary of what you think the problem is
    and a log of what happens when you run the script, in case I can't
    reproduce your problem on my system. If possible, don't have the
    script dependent on an existing 20Meg database. If the script you
    send me can create the database itself then that is preferred.

    I realise that in some cases this is easier said than done, so if
    you can only reproduce the problem in your existing script, then
    you can post me that if you want. Just don't expect me to find your
    problem in a hurry, or at all. :-)


CHANGES
-------

See the Changes file.

Paul Marquess <Paul.Marquess@btinternet.com>

