X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FStorage%2FDBI%2FSybase.pm;h=27d9f372ec2d4e42094e50c67ce8677187f7720c;hb=f49102d2abafb07215f9760bcfdf02b3502bc632;hp=c20a075fff55df7d8dbd0495eb5e947e372ebe77;hpb=310a0a0a7ccff74b1668a5009edd1f60a972f262;p=dbsrgits%2FDBIx-Class.git diff --git a/lib/DBIx/Class/Storage/DBI/Sybase.pm b/lib/DBIx/Class/Storage/DBI/Sybase.pm index c20a075..27d9f37 100644 --- a/lib/DBIx/Class/Storage/DBI/Sybase.pm +++ b/lib/DBIx/Class/Storage/DBI/Sybase.pm @@ -5,15 +5,28 @@ use warnings; use base qw/ DBIx::Class::Storage::DBI::Sybase::Common + DBIx::Class::Storage::DBI::AutoCast /; use mro 'c3'; use Carp::Clan qw/^DBIx::Class/; use List::Util (); +use Sub::Name (); __PACKAGE__->mk_group_accessors('simple' => - qw/_identity _blob_log_on_update auto_cast insert_txn/ + qw/_identity _blob_log_on_update _writer_storage _is_extra_storage + _bulk_storage _is_bulk_storage _began_bulk_work + _bulk_disabled_due_to_coderef_connect_info_warned + _identity_method/ ); +my @also_proxy_to_extra_storages = qw/ + connect_call_set_auto_cast auto_cast connect_call_blob_setup + connect_call_datetime_setup + + disconnect _connect_info _sql_maker _sql_maker_opts disable_sth_caching + auto_savepoint unsafe cursor_class debug debugobj schema +/; + =head1 NAME DBIx::Class::Storage::DBI::Sybase - Sybase support for DBIx::Class @@ -32,10 +45,7 @@ also enable that driver explicitly, see the documentation for more details. With this driver there is unfortunately no way to get the C without doing a C when placeholders are enabled. - -When using C transactions are -disabled. - -To turn off transactions for inserts (for an application that doesn't need -concurrency, or a loader, for example) use this setting in -L, - - on_connect_call => ['unsafe_insert'] - -To manipulate this setting at runtime, use: - - $schema->storage->insert_txn(0); # 1 to re-enable - -=cut - -sub connect_call_unsafe_insert { - my $self = shift; - $self->insert_txn(0); -} - sub _is_lob_type { my $self = shift; my $type = shift; $type && $type =~ /(?:text|image|lob|bytea|binary|memo)/i; } -# The select-piggybacking-on-insert trick stolen from odbc/mssql +sub _is_lob_column { + my ($self, $source, $column) = @_; + + return $self->_is_lob_type($source->column_info($column)->{data_type}); +} + sub _prep_for_execute { my $self = shift; my ($op, $extra_bind, $ident, $args) = @_; my ($sql, $bind) = $self->next::method (@_); -# Some combinations of FreeTDS and Sybase throw implicit conversion errors for -# all placeeholders, so we convert them into CASTs here. -# Based on code in ::DBI::NoBindVars . -# -# If we're using ::NoBindVars, there are no binds by this point so this code -# gets skippeed. - if ($self->auto_cast && @$bind) { - my $new_sql; - my @sql_part = split /\?/, $sql; - my $col_info = $self->_resolve_column_info($ident,[ map $_->[0], @$bind ]); - - foreach my $bound (@$bind) { - my $col = $bound->[0]; - my $syb_type = $self->_syb_base_type($col_info->{$col}{data_type}); - - foreach my $data (@{$bound}[1..$#$bound]) { - $new_sql .= shift(@sql_part) . - ($syb_type ? "CAST(? AS $syb_type)" : '?'); - } - } - $new_sql .= join '', @sql_part; - $sql = $new_sql; - } - if ($op eq 'insert') { my $table = $ident->from; my $bind_info = $self->_resolve_column_info( $ident, [map $_->[0], @{$bind}] ); - my $identity_col = -List::Util::first { $bind_info->{$_}{is_auto_increment} } (keys %$bind_info); + my $identity_col = List::Util::first + { $bind_info->{$_}{is_auto_increment} } + (keys %$bind_info) + ; if ($identity_col) { - $sql = -"SET IDENTITY_INSERT $table ON\n" . -"$sql\n" . -"SET IDENTITY_INSERT $table OFF" - } else { - $identity_col = List::Util::first { - $ident->column_info($_)->{is_auto_increment} - } $ident->columns; + $sql = join ("\n", + "SET IDENTITY_INSERT $table ON", + $sql, + "SET IDENTITY_INSERT $table OFF", + ); + } + else { + $identity_col = List::Util::first + { $ident->column_info($_)->{is_auto_increment} } + $ident->columns + ; } if ($identity_col) { @@ -281,9 +288,10 @@ List::Util::first { $bind_info->{$_}{is_auto_increment} } (keys %$bind_info); return ($sql, $bind); } -# Stolen from SQLT, with some modifications. This will likely change when the -# SQLT Sybase stuff is redone/fixed-up. -my %TYPE_MAPPING = ( +# Stolen from SQLT, with some modifications. This is a makeshift +# solution before a sane type-mapping library is available, thus +# the 'our' for easy overrides. +our %TYPE_MAPPING = ( number => 'numeric', money => 'money', varchar => 'varchar', @@ -301,11 +309,11 @@ my %TYPE_MAPPING = ( long => 'varchar', ); -sub _syb_base_type { +sub _native_data_type { my ($self, $type) = @_; $type = lc $type; - $type =~ s/ identity//; + $type =~ s/\s* identity//x; return uc($TYPE_MAPPING{$type} || $type); } @@ -313,7 +321,9 @@ sub _syb_base_type { sub _fetch_identity_sql { my ($self, $source, $col) = @_; - return "SELECT MAX($col) FROM ".$source->from; + return sprintf ("SELECT MAX(%s) FROM %s", + map { $self->sql_maker->_quote ($_) } ($col, $source->from) + ); } sub _execute { @@ -332,63 +342,370 @@ sub _execute { sub last_insert_id { shift->_identity } -# override to handle TEXT/IMAGE and to do a transaction if necessary +# handles TEXT/IMAGE and transaction for last_insert_id sub insert { - my ($self, $source, $to_insert) = splice @_, 0, 3; - my $dbh = $self->_dbh; + my $self = shift; + my ($source, $to_insert) = @_; my $blob_cols = $self->_remove_blob_cols($source, $to_insert); - my $need_last_insert_id = 0; - - my ($identity_col) = - map $_->[0], - grep $_->[1]{is_auto_increment}, - map [ $_, $source->column_info($_) ], + my $identity_col = List::Util::first + { $source->column_info($_)->{is_auto_increment} } $source->columns; - $need_last_insert_id = 1 - if $identity_col && (not exists $to_insert->{$identity_col}); - -# We have to do the insert in a transaction to avoid race conditions with the -# SELECT MAX(COL) identity method used when placeholders are enabled. - my $updated_cols = do { - if ($need_last_insert_id && $self->insert_txn && - (not $self->{transaction_depth})) { - my $args = \@_; - my $method = $self->next::can; - $self->txn_do( - sub { $self->$method($source, $to_insert, @$args) } - ); - } else { - $self->next::method($source, $to_insert, @_); - } + # do we need the horrific SELECT MAX(COL) hack? + my $dumb_last_insert_id = + $identity_col + && (not exists $to_insert->{$identity_col}) + && ($self->_identity_method||'') ne '@@IDENTITY'; + + my $next = $self->next::can; + + # we are already in a transaction, or there are no blobs + # and we don't need the PK - just (try to) do it + if ($self->{transaction_depth} + || (!$blob_cols && !$dumb_last_insert_id) + ) { + return $self->_insert ( + $next, $source, $to_insert, $blob_cols, $identity_col + ); + } + + # otherwise use the _writer_storage to do the insert+transaction on another + # connection + my $guard = $self->_writer_storage->txn_scope_guard; + + my $updated_cols = $self->_writer_storage->_insert ( + $next, $source, $to_insert, $blob_cols, $identity_col + ); + + $self->_identity($self->_writer_storage->_identity); + + $guard->commit; + + return $updated_cols; +} + +sub _insert { + my ($self, $next, $source, $to_insert, $blob_cols, $identity_col) = @_; + + my $updated_cols = $self->$next ($source, $to_insert); + + my $final_row = { + $identity_col => $self->last_insert_id($source, $identity_col), + %$to_insert, + %$updated_cols, }; - $self->_insert_blobs($source, $blob_cols, $to_insert) if %$blob_cols; + $self->_insert_blobs ($source, $blob_cols, $final_row) if $blob_cols; return $updated_cols; } sub update { - my ($self, $source) = splice @_, 0, 2; - my ($fields, $where) = @_; - my $wantarray = wantarray; + my $self = shift; + my ($source, $fields, $where, @rest) = @_; + + my $wantarray = wantarray; my $blob_cols = $self->_remove_blob_cols($source, $fields); + my $table = $source->name; + + my $identity_col = List::Util::first + { $source->column_info($_)->{is_auto_increment} } + $source->columns; + + my $is_identity_update = $identity_col && defined $fields->{$identity_col}; + + if (not $blob_cols) { + $self->_set_identity_insert($table, 'update') if $is_identity_update; + return $self->next::method(@_); + $self->_unset_identity_insert($table, 'update') if $is_identity_update; + } + +# check that we're not updating a blob column that's also in $where + for my $blob (grep $self->_is_lob_column($source, $_), $source->columns) { + if (exists $where->{$blob} && exists $fields->{$blob}) { + croak +'Update of TEXT/IMAGE column that is also in search condition impossible'; + } + } + +# update+blob update(s) done atomically on separate connection + $self = $self->_writer_storage; + + my $guard = $self->txn_scope_guard; + +# First update the blob columns to be updated to '' (taken from $fields, where +# it is originally put by _remove_blob_cols .) + my %blobs_to_empty = map { ($_ => delete $fields->{$_}) } keys %$blob_cols; + + $self->next::method($source, \%blobs_to_empty, $where, @rest); + +# Now update the blobs before the other columns in case the update of other +# columns makes the search condition invalid. + $self->_update_blobs($source, $blob_cols, $where); + my @res; - if ($wantarray) { - @res = $self->next::method($source, @_); - } else { - $res[0] = $self->next::method($source, @_); + if (%$fields) { + $self->_set_identity_insert($table, 'update') if $is_identity_update; + + if ($wantarray) { + @res = $self->next::method(@_); + } + elsif (defined $wantarray) { + $res[0] = $self->next::method(@_); + } + else { + $self->next::method(@_); + } + + $self->_unset_identity_insert($table, 'update') if $is_identity_update; } - $self->_update_blobs($source, $blob_cols, $where) if %$blob_cols; + $guard->commit; return $wantarray ? @res : $res[0]; } +### the insert_bulk partially stolen from DBI/MSSQL.pm + +sub _set_identity_insert { + my ($self, $table, $op) = @_; + + my $sql = sprintf ( + 'SET IDENTITY_%s %s ON', + (uc($op) || 'INSERT'), + $self->sql_maker->_quote ($table), + ); + + $self->_query_start($sql); + + my $dbh = $self->_get_dbh; + eval { $dbh->do ($sql) }; + my $exception = $@; + + $self->_query_end($sql); + + if ($exception) { + $self->throw_exception (sprintf "Error executing '%s': %s", + $sql, + $dbh->errstr, + ); + } +} + +sub _unset_identity_insert { + my ($self, $table, $op) = @_; + + my $sql = sprintf ( + 'SET IDENTITY_%s %s OFF', + (uc($op) || 'INSERT'), + $self->sql_maker->_quote ($table), + ); + + $self->_query_start($sql); + + my $dbh = $self->_get_dbh; + $dbh->do ($sql); + + $self->_query_end($sql); +} + +# for tests +sub _can_insert_bulk { 1 } + +sub insert_bulk { + my $self = shift; + my ($source, $cols, $data) = @_; + + my $is_identity_insert = (List::Util::first + { $source->column_info ($_)->{is_auto_increment} } @{$cols} + ) ? 1 : 0; + + my @source_columns = $source->columns; + + my $use_bulk_api = + $self->_bulk_storage && + $self->_get_dbh->{syb_has_blk}; + + if ((not $use_bulk_api) && + (Scalar::Util::reftype($self->_dbi_connect_info->[0])||'') eq 'CODE' && + (not $self->_bulk_disabled_due_to_coderef_connect_info_warned)) { + carp <<'EOF'; +Bulk API support disabled due to use of a CODEREF connect_info. Reverting to +array inserts. +EOF + $self->_bulk_disabled_due_to_coderef_connect_info_warned(1); + } + + if (not $use_bulk_api) { + if ($is_identity_insert) { + $self->_set_identity_insert ($source->name); + } + + $self->next::method(@_); + + if ($is_identity_insert) { + $self->_unset_identity_insert ($source->name); + } + + return; + } + +# otherwise, use the bulk API + +# rearrange @$data so that columns are in database order + my %orig_idx; + @orig_idx{@$cols} = 0..$#$cols; + + my %new_idx; + @new_idx{@source_columns} = 0..$#source_columns; + + my @new_data; + for my $datum (@$data) { + my $new_datum = []; + for my $col (@source_columns) { +# identity data will be 'undef' if not $is_identity_insert +# columns with defaults will also be 'undef' + $new_datum->[ $new_idx{$col} ] = + exists $orig_idx{$col} ? $datum->[ $orig_idx{$col} ] : undef; + } + push @new_data, $new_datum; + } + + my $identity_col = List::Util::first + { $source->column_info($_)->{is_auto_increment} } @source_columns; + +# bcp identity index is 1-based + my $identity_idx = exists $new_idx{$identity_col} ? + $new_idx{$identity_col} + 1 : 0; + +## Set a client-side conversion error handler, straight from DBD::Sybase docs. +# This ignores any data conversion errors detected by the client side libs, as +# they are usually harmless. + my $orig_cslib_cb = DBD::Sybase::set_cslib_cb( + Sub::Name::subname insert_bulk => sub { + my ($layer, $origin, $severity, $errno, $errmsg, $osmsg, $blkmsg) = @_; + + return 1 if $errno == 36; + + carp + "Layer: $layer, Origin: $origin, Severity: $severity, Error: $errno" . + ($errmsg ? "\n$errmsg" : '') . + ($osmsg ? "\n$osmsg" : '') . + ($blkmsg ? "\n$blkmsg" : ''); + + return 0; + }); + + eval { + my $bulk = $self->_bulk_storage; + + my $guard = $bulk->txn_scope_guard; + +## XXX get this to work instead of our own $sth +## will require SQLA or *Hacks changes for ordered columns +# $bulk->next::method($source, \@source_columns, \@new_data, { +# syb_bcp_attribs => { +# identity_flag => $is_identity_insert, +# identity_column => $identity_idx, +# } +# }); + my $sql = 'INSERT INTO ' . + $bulk->sql_maker->_quote($source->name) . ' (' . +# colname list is ignored for BCP, but does no harm + (join ', ', map $bulk->sql_maker->_quote($_), @source_columns) . ') '. + ' VALUES ('. (join ', ', ('?') x @source_columns) . ')'; + +## XXX there's a bug in the DBD::Sybase bulk support that makes $sth->finish for +## a prepare_cached statement ineffective. Replace with ->sth when fixed, or +## better yet the version above. Should be fixed in DBD::Sybase . + my $sth = $bulk->_get_dbh->prepare($sql, +# 'insert', # op + { + syb_bcp_attribs => { + identity_flag => $is_identity_insert, + identity_column => $identity_idx, + } + } + ); + + my $bind_attributes = $self->source_bind_attributes($source); + + foreach my $slice_idx (0..$#source_columns) { + my $col = $source_columns[$slice_idx]; + + my $attributes = $bind_attributes->{$col} + if $bind_attributes && defined $bind_attributes->{$col}; + + my @slice = map $_->[$slice_idx], @new_data; + + $sth->bind_param_array(($slice_idx + 1), \@slice, $attributes); + } + + $bulk->_query_start($sql); + +# this is stolen from DBI::insert_bulk + my $tuple_status = []; + my $rv = eval { $sth->execute_array({ArrayTupleStatus => $tuple_status}) }; + + if (my $err = $@ || $sth->errstr) { + my $i = 0; + ++$i while $i <= $#$tuple_status && !ref $tuple_status->[$i]; + + $self->throw_exception("Unexpected populate error: $err") + if ($i > $#$tuple_status); + + require Data::Dumper; + local $Data::Dumper::Terse = 1; + local $Data::Dumper::Indent = 1; + local $Data::Dumper::Useqq = 1; + local $Data::Dumper::Quotekeys = 0; + local $Data::Dumper::Sortkeys = 1; + + $self->throw_exception(sprintf "%s for populate slice:\n%s", + ($tuple_status->[$i][1] || $err), + Data::Dumper::Dumper( + { map { $source_columns[$_] => $new_data[$i][$_] } (0 .. $#$cols) } + ), + ); + } + + $guard->commit; + $sth->finish; + + $bulk->_query_end($sql); + }; + my $exception = $@; + if ($exception =~ /-Y option/) { + carp <<"EOF"; + +Sybase bulk API operation failed due to character set incompatibility, reverting +to regular array inserts: + +*** Try unsetting the LANG environment variable. + +$@ +EOF + $self->_bulk_storage(undef); + DBD::Sybase::set_cslib_cb($orig_cslib_cb); + unshift @_, $self; + goto \&insert_bulk; + } + elsif ($exception) { + DBD::Sybase::set_cslib_cb($orig_cslib_cb); +# rollback makes the bulkLogin connection unusable + $self->_bulk_storage->disconnect; + $self->throw_exception($exception); + } + + DBD::Sybase::set_cslib_cb($orig_cslib_cb); +} + +# Make sure blobs are not bound as placeholders, and return any non-empty ones +# as a hash. sub _remove_blob_cols { my ($self, $source, $fields) = @_; @@ -396,12 +713,18 @@ sub _remove_blob_cols { for my $col (keys %$fields) { if ($self->_is_lob_type($source->column_info($col)->{data_type})) { - $blob_cols{$col} = delete $fields->{$col}; - $fields->{$col} = \"''"; + my $blob_val = delete $fields->{$col}; + if (not defined $blob_val) { + $fields->{$col} = \'NULL'; + } + else { + $fields->{$col} = \"''"; + $blob_cols{$col} = $blob_val unless $blob_val eq ''; + } } } - return \%blob_cols; + return keys %blob_cols ? \%blob_cols : undef; } sub _update_blobs { @@ -424,14 +747,10 @@ sub _update_blobs { @row_to_update{@primary_cols} = @{$where}{@primary_cols}; @rows = \%row_to_update; } else { - my $rs = $source->resultset->search( - $where, - { - result_class => 'DBIx::Class::ResultClass::HashRefInflator', - select => \@primary_cols - } - ); - @rows = $rs->all; # statement must finish + my $cursor = $self->select ($source, \@primary_cols, $where, {}); + @rows = map { + my %row; @row{@primary_cols} = @$_; \%row + } $cursor->all; } for my $row (@rows) { @@ -441,9 +760,9 @@ sub _update_blobs { sub _insert_blobs { my ($self, $source, $blob_cols, $row) = @_; - my $dbh = $self->dbh; + my $dbh = $self->_get_dbh; - my $table = $source->from; + my $table = $source->name; my %row = %$row; my (@primary_cols) = $source->primary_columns; @@ -452,24 +771,30 @@ sub _insert_blobs { unless @primary_cols; if ((grep { defined $row{$_} } @primary_cols) != @primary_cols) { - if (@primary_cols == 1) { - my $col = $primary_cols[0]; - $row{$col} = $self->last_insert_id($source, $col); - } else { - croak "Cannot update TEXT/IMAGE column(s) without primary key values"; - } + croak "Cannot update TEXT/IMAGE column(s) without primary key values"; } for my $col (keys %$blob_cols) { my $blob = $blob_cols->{$col}; my %where = map { ($_, $row{$_}) } @primary_cols; - my $cursor = $source->resultset->search(\%where, { - select => [$col] - })->cursor; + + my $cursor = $self->select ($source, [$col], \%where, {}); $cursor->next; my $sth = $cursor->sth; + if (not $sth) { + require Data::Dumper; + local $Data::Dumper::Terse = 1; + local $Data::Dumper::Indent = 1; + local $Data::Dumper::Useqq = 1; + local $Data::Dumper::Quotekeys = 0; + local $Data::Dumper::Sortkeys = 1; + + croak "\nCould not find row in table '$table' for blob update:\n". + Data::Dumper::Dumper(\%where)."\n"; + } + eval { do { $sth->func('CS_GET', 1, 'ct_data_info') or die $sth->errstr; @@ -493,9 +818,10 @@ sub _insert_blobs { $sth->finish if $sth; if ($exception) { if ($self->using_freetds) { - croak -"TEXT/IMAGE operation failed, probably because you're using FreeTDS: " . -$exception; + croak ( + 'TEXT/IMAGE operation failed, probably because you are using FreeTDS: ' + . $exception + ); } else { croak $exception; } @@ -530,7 +856,7 @@ C columns only have minute precision. my $dbh = $self->_dbh; if ($dbh->can('syb_date_fmt')) { -# amazingly, this works with FreeTDS + # amazingly, this works with FreeTDS $dbh->syb_date_fmt('ISO_strict'); } elsif (not $old_dbd_warned) { carp "Your DBD::Sybase is too old to support ". @@ -554,10 +880,18 @@ sub datetime_parser_type { "DateTime::Format::Sybase" } sub _dbh_begin_work { my $self = shift; + +# bulkLogin=1 connections are always in a transaction, and can only call BEGIN +# TRAN once. However, we need to make sure there's a $dbh. + return if $self->_is_bulk_storage && $self->_dbh && $self->_began_bulk_work; + $self->next::method(@_); + if ($self->using_freetds) { - $self->dbh->do('BEGIN TRAN'); + $self->_get_dbh->do('BEGIN TRAN'); } + + $self->_began_bulk_work(1) if $self->_is_bulk_storage; } sub _dbh_commit { @@ -581,7 +915,7 @@ sub _dbh_rollback { sub _svp_begin { my ($self, $name) = @_; - $self->dbh->do("SAVE TRANSACTION $name"); + $self->_get_dbh->do("SAVE TRANSACTION $name"); } # A new SAVE TRANSACTION with the same name releases the previous one. @@ -590,7 +924,7 @@ sub _svp_release { 1 } sub _svp_rollback { my ($self, $name) = @_; - $self->dbh->do("ROLLBACK TRANSACTION $name"); + $self->_get_dbh->do("ROLLBACK TRANSACTION $name"); } 1; @@ -602,7 +936,7 @@ allow you to dump a schema from most (if not all) versions of Sybase. It is available via subversion from: - http://dev.catalyst.perl.org/repos/bast/branches/DBIx-Class-Schema-Loader/mssql_tweaks + http://dev.catalyst.perl.org/repos/bast/branches/DBIx-Class-Schema-Loader/current/ =head1 FreeTDS @@ -625,17 +959,69 @@ Some versions of the libraries involved will not support placeholders, in which case the storage will be reblessed to L. -In some configurations, placeholders will work but will throw implicit +In some configurations, placeholders will work but will throw implicit type conversion errors for anything that's not expecting a string. In such a case, -the C option is automatically set, which you may enable yourself with -L (see the description of that method for more -details.) +the C option from L is +automatically set, which you may enable on connection with +L. The type info +for the Cs is taken from the L +definitions in your Result classes, and are mapped to a Sybase type (if it isn't +already) using a mapping based on L. In other configurations, placeholers will work just as they do with the Sybase Open Client libraries. Inserts or updates of TEXT/IMAGE columns will B work with FreeTDS. +=head1 INSERTS WITH PLACEHOLDERS + +With placeholders enabled, inserts are done in a transaction so that there are +no concurrency issues with getting the inserted identity value using +C as it's a +session variable. + +=head1 TRANSACTIONS + +Due to limitations of the TDS protocol, L, or both; you cannot +begin a transaction while there are active cursors. An active cursor is, for +example, a L that has been executed using +C or C but has not been exhausted or +L. + +For example, this will not work: + + $schema->txn_do(sub { + my $rs = $schema->resultset('Book'); + while (my $row = $rs->next) { + $schema->resultset('MetaData')->create({ + book_id => $row->id, + ... + }); + } + }); + +Transactions done for inserts in C mode when placeholders are in use +are not affected, as they are done on an extra database handle. + +Some workarounds: + +=over 4 + +=item * use L + +=item * L another L + +=item * load the data from your cursor with L + +=back + =head1 MAXIMUM CONNECTIONS The TDS protocol makes separate connections to the server for active statements @@ -677,7 +1063,28 @@ C command on connection. See L for a L setting you need to work with C columns. -=head1 AUTHORS +=head1 BULK API + +The experimental L Bulk API support is used for +L in B context, in a transaction +on a separate connection. + +To use this feature effectively, use a large number of rows for each +L call, eg.: + + while (my $rows = $data_source->get_100_rows()) { + $rs->populate($rows); + } + +B the L +calls in your C classes B list columns in database order for this +to work. Also, you may have to unset the C environment variable before +loading your app, if it doesn't match the character set of your database. + +When inserting IMAGE columns using this method, you'll need to use +L as well. + +=head1 AUTHOR See L.