Create common infrastructure for cross-version upgrade testing.

To test pg_upgrade across major PG versions, we have to be able to
modify or drop any old objects with no-longer-supported properties,
and we have to be able to deal with cosmetic changes in pg_dump output.
Up to now, the buildfarm and pg_upgrade's own test infrastructure had
separate implementations of the former, and we had nothing but very
ad-hoc rules for the latter (including an arbitrary threshold on how
many lines of unchecked diff were okay!).  This patch creates a Perl
module that can be shared by both those use-cases, and adds logic
that deals with pg_dump output diffs in a much more tightly defined
fashion.

This largely supersedes previous efforts in commits 0df9641d3,
9814ff550, and 62be9e4cd, which developed a SQL-script-based solution
for the task of dropping old objects.  There was nothing fundamentally
wrong with that work in itself, but it had no basis for solving the
output-formatting problem.  The most plausible way to deal with
formatting is to build a Perl module that can perform editing on the
dump files; and once we commit to that, it makes more sense for the
same module to also embed the knowledge of what has to be done for
dropping old objects.

Back-patch versions of the helper module as far as 9.2, to
support buildfarm animals that still test that far back.
It's also necessary to back-patch PostgreSQL/Version.pm,
because the new code depends on that.  I fixed up pg_upgrade's
002_pg_upgrade.pl in v15, but did not look into back-patching
it further than that.

Tom Lane and Andrew Dunstan

Discussion: https://postgr.es/m/891521.1673657296@sss.pgh.pa.us
This commit is contained in:
Tom Lane 2023-01-16 20:35:53 -05:00
parent 877cfeb4fb
commit bfa3d27906
2 changed files with 512 additions and 0 deletions

View File

@ -0,0 +1,345 @@
# Copyright (c) 2023, PostgreSQL Global Development Group
=pod
=head1 NAME
PostgreSQL::Test::AdjustUpgrade - helper module for cross-version upgrade tests
=head1 SYNOPSIS
use PostgreSQL::Test::AdjustUpgrade;
# Build commands to adjust contents of old-version database before dumping
$statements = adjust_database_contents($old_version, %dbnames);
# Adjust contents of old pg_dumpall output file to match newer version
$dump = adjust_old_dumpfile($old_version, $dump);
# Adjust contents of new pg_dumpall output file to match older version
$dump = adjust_new_dumpfile($old_version, $dump);
=head1 DESCRIPTION
C<PostgreSQL::Test::AdjustUpgrade> encapsulates various hacks needed to
compare the results of cross-version upgrade tests.
=cut
package PostgreSQL::Test::AdjustUpgrade;
use strict;
use warnings;
use Exporter 'import';
use PostgreSQL::Version;
our @EXPORT = qw(
adjust_database_contents
adjust_old_dumpfile
adjust_new_dumpfile
);
=pod
=head1 ROUTINES
=over
=item $statements = adjust_database_contents($old_version, %dbnames)
Generate SQL commands to perform any changes to an old-version installation
that are needed before we can pg_upgrade it into the current PostgreSQL
version.
Typically this involves dropping or adjusting no-longer-supported objects.
Arguments:
=over
=item C<old_version>: Branch we are upgrading from, represented as a
PostgreSQL::Version object.
=item C<dbnames>: Hash of database names present in the old installation.
=back
Returns a reference to a hash, wherein the keys are database names and the
values are arrayrefs to lists of statements to be run in those databases.
=cut
sub adjust_database_contents
{
my ($old_version, %dbnames) = @_;
my $result = {};
# remove dbs of modules known to cause pg_upgrade to fail
# anything not builtin and incompatible should clean up its own db
foreach my $bad_module ('test_ddl_deparse', 'tsearch2')
{
if ($dbnames{"contrib_regression_$bad_module"})
{
_add_st($result, 'postgres',
"drop database contrib_regression_$bad_module");
delete($dbnames{"contrib_regression_$bad_module"});
}
}
# avoid version number issues with test_ext7
if ($dbnames{contrib_regression_test_extensions})
{
_add_st(
$result,
'contrib_regression_test_extensions',
'drop extension if exists test_ext7');
}
# get rid of dblink's dependencies on regress.so
my $regrdb =
$old_version le '9.4'
? 'contrib_regression'
: 'contrib_regression_dblink';
if ($dbnames{$regrdb})
{
_add_st(
$result, $regrdb,
'drop function if exists public.putenv(text)',
'drop function if exists public.wait_pid(integer)');
}
if ($old_version lt '9.5')
{
# cope with changes of underlying functions
_add_st(
$result,
'regression',
'drop operator @#@ (NONE, bigint)',
'CREATE OPERATOR @#@ ('
. 'PROCEDURE = factorial, RIGHTARG = bigint )',
'drop aggregate public.array_cat_accum(anyarray)',
'CREATE AGGREGATE array_larger_accum (anyarray) ' . ' ( '
. ' sfunc = array_larger, '
. ' stype = anyarray, '
. ' initcond = $${}$$ ' . ' ) ');
# "=>" is no longer valid as an operator name
_add_st($result, 'regression',
'drop operator if exists public.=> (bigint, NONE)');
}
return $result;
}
# Internal subroutine to add statement(s) to the list for the given db.
sub _add_st
{
my ($result, $db, @st) = @_;
$result->{$db} ||= [];
push(@{ $result->{$db} }, @st);
}
=pod
=item adjust_old_dumpfile($old_version, $dump)
Edit a dump output file, taken from the adjusted old-version installation
by current-version C<pg_dumpall -s>, so that it will match the results of
C<pg_dumpall -s> on the pg_upgrade'd installation.
Typically this involves coping with cosmetic differences in the output
of backend subroutines used by pg_dump.
Arguments:
=over
=item C<old_version>: Branch we are upgrading from, represented as a
PostgreSQL::Version object.
=item C<dump>: Contents of dump file
=back
Returns the modified dump text.
=cut
sub adjust_old_dumpfile
{
my ($old_version, $dump) = @_;
# use Unix newlines
$dump =~ s/\r\n/\n/g;
# Version comments will certainly not match.
$dump =~ s/^-- Dumped from database version.*\n//mg;
if ($old_version lt '9.5')
{
# adjust some places where we don't print so many parens anymore
my $prefix = "CONSTRAINT (?:sequence|copy)_con CHECK [(][(]";
my $orig = "((x > 3) AND (y <> 'check failed'::text))";
my $repl = "(x > 3) AND (y <> 'check failed'::text)";
$dump =~ s/($prefix)\Q$orig\E/$1$repl/mg;
$prefix = "CONSTRAINT insert_con CHECK [(][(]";
$orig = "((x >= 3) AND (y <> 'check failed'::text))";
$repl = "(x >= 3) AND (y <> 'check failed'::text)";
$dump =~ s/($prefix)\Q$orig\E/$1$repl/mg;
$orig = "DEFAULT ((-1) * currval('public.insert_seq'::regclass))";
$repl =
"DEFAULT ('-1'::integer * currval('public.insert_seq'::regclass))";
$dump =~ s/\Q$orig\E/$repl/mg;
my $expr =
"(rsl.sl_color = rsh.slcolor) AND (rsl.sl_len_cm >= rsh.slminlen_cm)";
$dump =~ s/WHERE \(\(\Q$expr\E\)/WHERE ($expr/g;
$expr =
"(rule_and_refint_t3.id3a = new.id3a) AND (rule_and_refint_t3.id3b = new.id3b)";
$dump =~ s/WHERE \(\(\Q$expr\E\)/WHERE ($expr/g;
$expr =
"(rule_and_refint_t3_1.id3a = new.id3a) AND (rule_and_refint_t3_1.id3b = new.id3b)";
$dump =~ s/WHERE \(\(\Q$expr\E\)/WHERE ($expr/g;
}
if ($old_version lt '9.3')
{
# CREATE VIEW/RULE statements were not pretty-printed before 9.3.
# To cope, reduce all whitespace sequences within them to one space.
# This must be done on both old and new dumps.
$dump = _mash_view_whitespace($dump);
# _mash_view_whitespace doesn't handle multi-command rules;
# rather than trying to fix that, just hack the exceptions manually.
my $prefix =
"CREATE RULE rtest_sys_del AS ON DELETE TO public.rtest_system DO (DELETE FROM public.rtest_interface WHERE (rtest_interface.sysname = old.sysname);";
my $line2 = " DELETE FROM public.rtest_admin";
my $line3 = " WHERE (rtest_admin.sysname = old.sysname);";
$dump =~
s/(?<=\Q$prefix\E)\Q$line2$line3\E \);/\n$line2\n $line3\n);/mg;
$prefix =
"CREATE RULE rtest_sys_upd AS ON UPDATE TO public.rtest_system DO (UPDATE public.rtest_interface SET sysname = new.sysname WHERE (rtest_interface.sysname = old.sysname);";
$line2 = " UPDATE public.rtest_admin SET sysname = new.sysname";
$line3 = " WHERE (rtest_admin.sysname = old.sysname);";
$dump =~
s/(?<=\Q$prefix\E)\Q$line2$line3\E \);/\n$line2\n $line3\n);/mg;
# and there's one place where pre-9.3 uses a different table alias
$dump =~ s {^(CREATE\sRULE\srule_and_refint_t3_ins\sAS\s
ON\sINSERT\sTO\spublic\.rule_and_refint_t3\s
WHERE\s\(EXISTS\s\(SELECT\s1\sFROM\spublic\.rule_and_refint_t3)\s
(WHERE\s\(\(rule_and_refint_t3)
(\.id3a\s=\snew\.id3a\)\sAND\s\(rule_and_refint_t3)
(\.id3b\s=\snew\.id3b\)\sAND\s\(rule_and_refint_t3)}
{$1 rule_and_refint_t3_1 $2_1$3_1$4_1}mx;
# Also fix old use of NATURAL JOIN syntax
$dump =~ s {NATURAL JOIN public\.credit_card r}
{JOIN public.credit_card r USING (cid)}mg;
$dump =~ s {NATURAL JOIN public\.credit_usage r}
{JOIN public.credit_usage r USING (cid)}mg;
}
# Suppress blank lines, as some places in pg_dump emit more or fewer.
$dump =~ s/\n\n+/\n/g;
return $dump;
}
# Internal subroutine to mangle whitespace within view/rule commands.
# Any consecutive sequence of whitespace is reduced to one space.
sub _mash_view_whitespace
{
my ($dump) = @_;
foreach my $leader ('CREATE VIEW', 'CREATE RULE')
{
my @splitchunks = split $leader, $dump;
$dump = shift(@splitchunks);
foreach my $chunk (@splitchunks)
{
my @thischunks = split /;/, $chunk, 2;
my $stmt = shift(@thischunks);
# now $stmt is just the body of the CREATE VIEW/RULE
$stmt =~ s/\s+/ /sg;
# we also need to smash these forms for sub-selects and rules
$stmt =~ s/\( SELECT/(SELECT/g;
$stmt =~ s/\( INSERT/(INSERT/g;
$stmt =~ s/\( UPDATE/(UPDATE/g;
$stmt =~ s/\( DELETE/(DELETE/g;
$dump .= $leader . $stmt . ';' . $thischunks[0];
}
}
return $dump;
}
=pod
=item adjust_new_dumpfile($old_version, $dump)
Edit a dump output file, taken from the pg_upgrade'd installation
by current-version C<pg_dumpall -s>, so that it will match the old
dump output file as adjusted by C<adjust_old_dumpfile>.
Typically this involves deleting data not present in the old installation.
Arguments:
=over
=item C<old_version>: Branch we are upgrading from, represented as a
PostgreSQL::Version object.
=item C<dump>: Contents of dump file
=back
Returns the modified dump text.
=cut
sub adjust_new_dumpfile
{
my ($old_version, $dump) = @_;
# use Unix newlines
$dump =~ s/\r\n/\n/g;
# Version comments will certainly not match.
$dump =~ s/^-- Dumped from database version.*\n//mg;
if ($old_version lt '9.3')
{
# CREATE VIEW/RULE statements were not pretty-printed before 9.3.
# To cope, reduce all whitespace sequences within them to one space.
# This must be done on both old and new dumps.
$dump = _mash_view_whitespace($dump);
}
# Suppress blank lines, as some places in pg_dump emit more or fewer.
$dump =~ s/\n\n+/\n/g;
return $dump;
}
=pod
=back
=cut
1;

View File

@ -0,0 +1,167 @@
############################################################################
#
# PostgreSQL/Version.pm
#
# Module encapsulating Postgres Version numbers
#
# Copyright (c) 2021-2022, PostgreSQL Global Development Group
#
############################################################################
=pod
=head1 NAME
PostgreSQL::Version - class representing PostgreSQL version numbers
=head1 SYNOPSIS
use PostgreSQL::Version;
my $version = PostgreSQL::Version->new($version_arg);
# compare two versions
my $bool = $version1 <= $version2;
# or compare with a number
$bool = $version < 12;
# or with a string
$bool = $version lt "13.1";
# interpolate in a string
my $stringyval = "version: $version";
# get the major version
my $maj = $version->major;
=head1 DESCRIPTION
PostgreSQL::Version encapsulates Postgres version numbers, providing parsing
of common version formats and comparison operations.
=cut
package PostgreSQL::Version;
use strict;
use warnings;
use Scalar::Util qw(blessed);
use overload
'<=>' => \&_version_cmp,
'cmp' => \&_version_cmp,
'""' => \&_stringify;
=pod
=head1 METHODS
=over
=item PostgreSQL::Version->new($version)
Create a new PostgreSQL::Version instance.
The argument can be a number like 12, or a string like '12.2' or the output
of a Postgres command like `psql --version` or `pg_config --version`;
=back
=cut
sub new
{
my $class = shift;
my $arg = shift;
chomp $arg;
# Accept standard formats, in case caller has handed us the output of a
# postgres command line tool
my $devel;
($arg, $devel) = ($1, $2)
if (
$arg =~ m!^ # beginning of line
(?:\(?PostgreSQL\)?\s)? # ignore PostgreSQL marker
(\d+(?:\.\d+)*) # version number, dotted notation
(devel|(?:alpha|beta|rc)\d+)? # dev marker - see version_stamp.pl
!x);
# Split into an array
my @numbers = split(/\./, $arg);
# Treat development versions as having a minor/micro version one less than
# the first released version of that branch.
push @numbers, -1 if ($devel);
$devel ||= "";
return bless { str => "$arg$devel", num => \@numbers }, $class;
}
# Routine which compares the _pg_version_array obtained for the two
# arguments and returns -1, 0, or 1, allowing comparison between two
# PostgreSQL::Version objects or a PostgreSQL::Version and a version string or number.
#
# If the second argument is not a blessed object we call the constructor
# to make one.
#
# Because we're overloading '<=>' and 'cmp' this function supplies us with
# all the comparison operators ('<' and friends, 'gt' and friends)
#
sub _version_cmp
{
my ($a, $b, $swapped) = @_;
$b = __PACKAGE__->new($b) unless blessed($b);
($a, $b) = ($b, $a) if $swapped;
my ($an, $bn) = ($a->{num}, $b->{num});
for (my $idx = 0;; $idx++)
{
return 0
if ($idx >= @$an && $idx >= @$bn);
# treat a missing number as 0
my ($anum, $bnum) = ($an->[$idx] || 0, $bn->[$idx] || 0);
return $anum <=> $bnum
if ($anum <=> $bnum);
}
}
# Render the version number using the saved string.
sub _stringify
{
my $self = shift;
return $self->{str};
}
=pod
=over
=item major([separator => 'char'])
Returns the major version. For versions before 10 the parts are separated by
a dot unless the separator argument is given.
=back
=cut
sub major
{
my ($self, %params) = @_;
my $result = $self->{num}->[0];
if ($result + 0 < 10)
{
my $sep = $params{separator} || '.';
$result .= "$sep$self->{num}->[1]";
}
return $result;
}
1;