1DBIx::Class::Manual::TrUosuebrleCsohnotortiibnugt(e3d)PDeBrIlx:D:oCcluamsesn:t:aMtainounal::Troubleshooting(3)
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6 DBIx::Class::Manual::Troubleshooting - Got a problem? Shoot it.
7 "Can't locate storage blabla"
9 You're trying to make a query on a non-connected schema. Make sure you
10 got the current resultset from $schema->resultset('Artist') on a schema
11 object you got back from connect().
12 Tracing SQL
14 The "DBIC_TRACE" environment variable controls SQL tracing, so to see
15 what is happening try
16 export DBIC_TRACE=1
18 Alternatively use the "storage->debug" class method:-
20 $schema->storage->debug(1);
22 To send the output somewhere else set debugfh:-
24 $schema->storage->debugfh(IO::File->new('/tmp/trace.out', 'w');
26 Alternatively you can do this with the environment variable, too:-
28 export DBIC_TRACE="1=/tmp/trace.out"
30 Can't locate method result_source_instance
32 For some reason the table class in question didn't load fully, so the
33 ResultSource object for it hasn't been created. Debug this class in
34 isolation, then try loading the full schema again.
35 Can't get last insert ID under Postgres with serial primary keys
37 Older DBI and DBD::Pg versions do not handle "last_insert_id"
38 correctly, causing code that uses auto-incrementing primary key columns
39 to fail with a message such as:
40 Can't get last insert id at /.../DBIx/Class/Row.pm line 95
42 In particular the RHEL 4 and FC3 Linux distributions both ship with
44 combinations of DBI and DBD::Pg modules that do not work correctly.
45 DBI version 1.50 and DBD::Pg 1.43 are known to work.
47 Can't locate object method "source_name" via package
49 There's likely a syntax error in the table class referred to elsewhere
50 in this error message. In particular make sure that the package
51 declaration is correct. For example, for a schema " MySchema " you need
52 to specify a fully qualified namespace: " package MySchema::MyTable; ".
53 syntax error at or near "<something>" ...
55 This can happen if you have a relation whose name is a word reserved by
56 your database, e.g. "user":
57 package My::Schema::User;
59 ...
60 __PACKAGE__->table('users');
61 __PACKAGE__->add_columns(qw/ id name /);
62 __PACKAGE__->set_primary_key('id');
63 ...
64 1;
65 package My::Schema::ACL;
67 ...
68 __PACKAGE__->table('acl');
69 __PACKAGE__->add_columns(qw/ user_id /);
70 __PACKAGE__->belongs_to( 'user' => 'My::Schema::User', 'user_id' );
71 ...
72 1;
73 $schema->resultset('ACL')->search(
75 {},
76 {
77 join => [qw/ user /],
78 '+select' => [ 'user.name' ]
79 }
80 );
81 The SQL generated would resemble something like:
83 SELECT me.user_id, user.name FROM acl me
85 JOIN users user ON me.user_id = user.id
86 If, as is likely, your database treats "user" as a reserved word, you'd
88 end up with the following errors:
89 1) syntax error at or near "." - due to "user.name" in the SELECT
91 clause
92 2) syntax error at or near "user" - due to "user" in the JOIN clause
94 The solution is to enable quoting - see
96 "Setting_quoting_for_the_generated_SQL" in
97 DBIx::Class::Manual::Cookbook for details.
98 column "foo DESC" does not exist ...
100 This can happen if you are still using the obsolete order hack, and
101 also happen to turn on SQL-quoting.
102 $rs->search( {}, { order_by => [ 'name DESC' ] } );
104 Since DBIx::Class >= 0.08100 and SQL::Abstract >= 1.50 the above should
106 be written as:
107 $rs->search( {}, { order_by => { -desc => 'name' } } );
109 For more ways to express order clauses refer to "ORDER_BY_CLAUSES" in
111 SQL::Abstract
112 Perl Performance Issues on Red Hat Systems
114 There is a problem with slow performance of certain DBIx::Class
115 operations using the system perl on some Fedora and Red Hat Enterprise
116 Linux system (as well as their derivative distributions such as Centos,
117 White Box and Scientific Linux).
118 Distributions affected include Fedora 5 through to Fedora 8 and RHEL5
120 upto and including RHEL5 Update 2. Fedora 9 (which uses perl 5.10) has
121 never been affected - this is purely a perl 5.8.8 issue.
122 As of September 2008 the following packages are known to be fixed and
124 so free of this performance issue (this means all Fedora and RHEL5
125 systems with full current updates will not be subject to this
126 problem):-
127 Fedora 8 - perl-5.8.8-41.fc8
129 RHEL5 - perl-5.8.8-15.el5_2.1
130 This issue is due to perl doing an exhaustive search of blessed objects
132 under certain circumstances. The problem shows up as performance
133 degradation exponential to the number of DBIx::Class row objects in
134 memory, so can be unnoticeable with certain data sets, but with huge
135 performance impacts on other datasets.
136 A pair of tests for susceptibility to the issue and performance effects
138 of the bless/overload problem can be found in the DBIx::Class test
139 suite, in the "t/99rh_perl_perf_bug.t" file.
140 Further information on this issue can be found in
142 <https://bugzilla.redhat.com/show_bug.cgi?id=379791>,
143 <https://bugzilla.redhat.com/show_bug.cgi?id=460308> and
144 http://rhn.redhat.com/errata/RHBA-2008-0876.html
145 <http://rhn.redhat.com/errata/RHBA-2008-0876.html>
146 Excessive Memory Allocation with TEXT/BLOB/etc. Columns and Large
148 LongReadLen
149 It has been observed, using DBD::ODBC, that creating a DBIx::Class::Row
150 object which includes a column of data type TEXT/BLOB/etc. will
151 allocate LongReadLen bytes. This allocation does not leak, but if
152 LongReadLen is large in size, and many such row objects are created,
153 e.g. as the output of a ResultSet query, the memory footprint of the
154 Perl interpreter can grow very large.
155 The solution is to use the smallest practical value for LongReadLen.
157perl v5.12.0 2010-0D5B-I1x2::Class::Manual::Troubleshooting(3)