changes.pm

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=head1 NAME

DBI::Changes - List of significant changes to the DBI

(As of $Date: 2007-10-21 23:05:38 +0100 (Sun, 21 Oct 2007) $ $Revision: 10103 $)

=cut

Assorted TODO notes:

Protect trace_msg from SIGPIPE?
prepare(...,{ Err=>\my $isolated_err, ...})
Move _new_sth to DBI::db::_new_sth (leave alias) and implement in C
Implement FETCH_many() in C
Or call _new_child and move to DBI::common?
Add trace modules that just records the last N trace messages into an array
and prepends them to any error message.
Document DBI_PROFILE_FLOCK and LockFile attrib in DBI::ProfileData and DBI::ProfileDumper

Gofo TODOs:

Add count of identical frozen_request (plus sum(results size)) to Gofer status
    Highlight those seen before.
Move post-request cleanup into separate method and enable hooks so
    it can be done after the response has been sent
Gofer - allow dbh attrib changes after connect?
    note them and pass in request as STORE method calls
    but then gofer server need to reset them to restore dbh to original state
    Or, change the attr in the connect() call, but that risks
    bloating the number of cache dbh in the server.
Gofer request flags for:
    - return current executor stats as an attribute - handy for tests
    - will accept streamed resultsets
Add attr-passthru to prepare()? ie for gofer cache control & ReadOnly
Terminology for client and server ends
Document user/passwd issues at the various levels of the gofer stack
Policy's from pod
Policy for dbh attr FETCH (ie example_driver_path)
    or piggyback on skip_connect_check
    could also remember which attr have been returned to us
    so not bother FETCHing them (unless pedantic)
Call method on transport failure so transport can cleanup/reset if it wants
Gofer: gearman - need to disable coallesing for non-idempotent requests

=head2 Changes in DBI 1.601 (svn rev 10103),  21st October 2007

  Fixed t/05thrclone.t to work with Test::More >= 0.71
    thanks to Jerry D. Hedden and Michael G Schwern.
  Fixed DBI for VMS thanks to Peter (Stig) Edwards.

  Added client-side caching to DBD::Gofer. Can use any cache with
    get($k)/set($k,$v) methods, including all the Cache and Cache::Cache
    distribution modules plus Cache::Memcached, Cache::FastMmap etc.
    Works for all transports. Overridable per handle.

  Added DBI::Util::CacheMemory for use with DBD::Gofer caching.
    It's a very fast and small strict subset of Cache::Memory.

=head2 Changes in DBI 1.59 (svn rev 9874),  23rd August 2007

  Fixed DBI::ProfileData to unescape headers lines read from data file.
  Fixed DBI::ProfileData to not clobber $_, thanks to Alexey Tourbin.
  Fixed DBI::SQL::Nano to not clobber $_, thanks to Alexey Tourbin.
  Fixed DBI::PurePerl to return undef for ChildHandles if weaken not available.
  Fixed DBD::Proxy disconnect error thanks to Philip Dye.
  Fixed DBD::Gofer::Transport::Base bug (typo) in timeout code.
  Fixed DBD::Proxy rows method thanks to Philip Dye.
  Fixed dbiprof compile errors, thanks to Alexey Tourbin.
  Fixed t/03handle.t to skip some tests if ChildHandles not available.

  Added check_response_sub to DBI::Gofer::Execute

=head2 Changes in DBI 1.58 (svn rev 9678),  25th June 2007

  Fixed code triggering fatal error in bleadperl, thanks to Steve Hay.
  Fixed compiler warning thanks to Jerry D. Hedden.
  Fixed t/40profile.t to use int(dbi_time()) for systems like Cygwin where
    time() seems to be rounded not truncated from the high resolution time.
  Removed dump_results() test from t/80proxy.t.

=head2 Changes in DBI 1.57 (svn rev 9639),  13th June 2007

  Note: this release includes a change to the DBI::hash() function which will
  now produce different values than before *if* your perl was built with 64-bit
  'int' type (i.e. "perl -V:intsize" says intsize='8').  It's relatively rare
  for perl to be configured that way, even on 64-bit systems.

  Fixed XS versions of select*_*() methods to call execute()
    fetch() etc., with inner handle instead of outer.
  Fixed execute_for_fetch() to not cache errstr values
    thanks to Bart Degryse.
  Fixed unused var compiler warning thanks to JDHEDDEN.
  Fixed t/86gofer_fail tests to be less likely to fail falsely.

  Changed DBI::hash to return 'I32' type instead of 'int' so results are
    portable/consistent regardless of size of the int type.
  Corrected timeout example in docs thanks to Egmont Koblinger.
  Changed t/01basic.t to warn instead of failing when it detects
    a problem with Math::BigInt (some recent versions had problems).

  Added support for !Time and !Time~N to DBI::Profile Path. See docs.
  Added extra trace info to connect_cached thanks to Walery Studennikov.
  Added non-random (deterministic) mode to DBI_GOFER_RANDOM mechanism.
  Added DBIXS_REVISION macro that drivers can use.
  Added more docs for private_attribute_info() method.

  DBI::Profile changes:
    dbi_profile() now returns ref to relevant leaf node.
    Don't profile DESTROY during global destruction.
    Added as_node_path_list() and as_text() methods.
  DBI::ProfileDumper changes:
    Don't write file if there's no profile data.
    Uses full natural precision when saving data (was using %.6f)
    Optimized flush_to_disk().
    Locks the data file while writing.
    Enabled filename to be a code ref for dynamic names.
  DBI::ProfileDumper::Apache changes:
    Added Quiet=>1 to avoid write to STDERR in flush_to_disk().
    Added Dir=>... to specify a writable destination directory.
    Enabled DBI_PROFILE_APACHE_LOG_DIR for mod_perl 1 as well as 2.
    Added parent pid to default data file name.
  DBI::ProfileData changes:
    Added DeleteFiles option to rename & delete files once read.
    Locks the data files while reading.
    Added ability to sort by Path elements.
  dbiprof changes:
    Added --dumpnodes and --delete options.
  Added/updated docs for both DBI::ProfileDumper && ::Apache.

=head2 Changes in DBI 1.56 (svn rev 9660),  18th June 2007

  Fixed printf arg warnings thanks to JDHEDDEN.
  Fixed returning driver-private sth attributes via gofer.   

  Changed pod docs docs to use =head3 instead of =item
    so now in html you get links to individual methods etc.
  Changed default gofer retry_limit from 2 to 0.
  Changed tests to workaround Math::BigInt broken versions.
  Changed dbi_profile_merge() to dbi_profile_merge_nodes()
    old name still works as an alias for the new one.
  Removed old DBI internal sanity check that's no longer valid
    causing "panic: DESTROY (dbih_clearcom)" when tracing enabled

  Added DBI_GOFER_RANDOM env var that can be use to trigger random
    failures and delays when executing gofer requests. Designed to help
    test automatic retry on failures and timeout handling.
  Added lots more docs to all the DBD::Gofer and DBI::Gofer classes.

=head2 Changes in DBI 1.55 (svn rev 9504),  4th May 2007

  Fixed set_err() so HandleSetErr hook is executed reliably, if set.
  Fixed accuracy of profiling when perl configured to use long doubles.
  Fixed 42prof_data.t on fast systems with poor timers thanks to Malcolm Nooning.
  Fixed potential corruption in selectall_arrayref and selectrow_arrayref
    for compiled drivers, thanks to Rob Davies.
    Rebuild your compiled drivers after installing DBI.

  Changed some handle creation code from perl to C code,
    to reduce handle creation cost by ~20%.
  Changed internal implementation of the CachedKids attribute
    so it's a normal handle attribute (and initially undef).
  Changed connect_cached and prepare_cached to avoid a FETCH method call,
    and thereby reduced cost by ~5% and ~30% respectively.
  Changed _set_fbav to not croak when given a wrongly sized array,
    it now warns and adjusts the row buffer to match.
  Changed some internals to improve performance with threaded perls.
  Changed DBD::NullP to be slightly more useful for testing.
  Changed File::Spec prerequisite to not require a minimum version.
  Changed tests to work with other DBMs thanks to ZMAN.
  Changed ex/perl_dbi_nulls_test.pl to be more descriptive.

  Added more functionality to the (undocumented) Callback mechanism.
    Callbacks can now elect to provide a value to be returned, in which case
    the method won't be called. A callback for "*" is applied to all methods
    that don't have their own callback.
  Added $h->{ReadOnly} attribute.
  Added support for DBI Profile Path to contain refs to scalars
    which will be de-ref'd for each profile sample.
  Added dbilogstrip utility to edit DBI logs for diff'ing (gets installed)
  Added details for SQLite 3.3 to NULL handling docs thanks to Alex Teslik.
  Added take_imp_data() to DBI::PurePerl.

  Gofer related changes:
    Fixed gofer pipeone & stream transports to avoid risk of hanging.
    Improved error handling and tracing significantly.
    Added way to generate random 1-in-N failures for methods.
    Added automatic retry-on-error mechanism to gofer transport base class.
    Added tests to show automatic retry mechanism works a treat!
    Added go_retry_hook callback hook so apps can fine-tune retry behaviour.
    Added header to request and response packets for sanity checking
      and to enable version skew between client and server.
    Added forced_single_resultset, max_cached_sth_per_dbh and max_cached_dbh_per_drh
      to gofer executor config.
    Driver-private methods installed with install_method are now proxied.
    No longer does a round-trip to the server for methods it knows
      have not been overridden by the remote driver.
    Most significant aspects of gofer behaviour are controlled by policy mechanism.
    Added policy-controlled caching of results for some methods, such as schema metadata.
    The connect_cached and prepare_cached methods cache on client and server.
    The bind_param_array and execute_array methods are now supported.
    Worked around a DBD::Sybase bind_param bug (which is fixed in DBD::Sybase 1.07)
    Added goferperf.pl utility (doesn't get installed).
    Many other assorted Gofer related bug fixes, enhancements and docs.
    The http and mod_perl transports have been remove to their own distribution.
    Client and server will need upgrading together for this release.

=head2 Changes in DBI 1.54 (svn rev 9157),  23rd February 2007

  NOTE: This release includes the 'next big thing': DBD::Gofer.
  Take a look!

  WARNING: This version has some subtle changes in DBI internals.
  It's possible, though doubtful, that some may affect your code.
  I recommend some extra testing before using this release.
  Or perhaps I'm just being over cautious...

  Fixed type_info when called for multiple dbh thanks to Cosimo Streppone.
  Fixed compile warnings in bleadperl on freebsd-6.1-release
    and solaris 10g thanks to Philip M. Gollucci.
  Fixed to compile for perl built with -DNO_MATHOMS thanks to Jerry D. Hedden.
  Fixed to work for bleadperl (r29544) thanks to Nicholas Clark.
    Users of Perl >= 5.9.5 will require DBI >= 1.54.
  Fixed rare error when profiling access to $DBI::err etc tied variables.
  Fixed DBI::ProfileDumper to not be affected by changes to $/ and $,
    thanks to Michael Schwern.

  Changed t/40profile.t to skip tests for perl < 5.8.0.
  Changed setting trace file to no longer write "Trace file set" to new file.
  Changed 'handle cleared whilst still active' warning for dbh
    to only be given for dbh that have active sth or are not AutoCommit.
  Changed take_imp_data to call finish on all Active child sth.
  Changed DBI::PurePerl trace() method to be more consistent.
  Changed set_err method to effectively not append to errstr if the new errstr
    is the same as the current one.
  Changed handle factory methods, like connect, prepare, and table_info,
    to copy any error/warn/info state of the handle being returned
    up into the handle the method was called on.
  Changed row buffer handling to not alter NUM_OF_FIELDS if it's
    inconsistent with number of elements in row buffer array.
  Updated DBI::DBD docs re handling multiple result sets.
  Updated DBI::DBD docs for driver authors thanks to Ammon Riley
    and Dean Arnold.
  Updated column_info docs to note that if a table doesn't exist
    you get an sth for an empty result set and not an error.

  Added new DBD::Gofer 'stateless proxy' driver and framework,
    and the DBI test suite is now also executed via DBD::Gofer,
    and DBD::Gofer+DBI::PurePerl, in addition to DBI::PurePerl.
  Added ability for trace() to support filehandle argument,