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Use SELECT * instead of SELECT COUNT(*) to avoid 'Select tables optimized away'. Make _get_row_estimate() "public".

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This commit is contained in:
Daniel Nichter
2011-11-17 12:15:21 -07:00
parent 41be2d9e2c
commit 7b8736c1f5
1 changed files with 6 additions and 6 deletions
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12
lib/NibbleIterator.pm
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@@ -61,8 +61,9 @@ sub new {
die "I need a $arg argument" unless $args{$arg};
}
my ($cxn, $tbl, $chunk_size, $o, $q) = @args{@required_args};
my ($row_est, $mysql_index) = _get_row_estimate(%args);
my $where = $o->get('where');
my ($row_est, $mysql_index) = get_row_estimate(%args, where => $where);
my $one_nibble = !defined $args{one_nibble} || $args{one_nibble}
? $row_est <= $chunk_size * $o->get('chunk-size-limit')
: 0;
@@ -85,7 +86,6 @@ sub new {
my $ignore_col = $o->get('ignore-columns') || {};
my $all_cols = $o->get('columns') || $tbl_struct->{cols};
my @cols = grep { !$ignore_col->{$_} } @$all_cols;
my $where = $o->get('where');
my $self;
if ( $one_nibble ) {
# If the chunk size is >= number of rows in table, then we don't
@@ -509,15 +509,15 @@ sub _get_index_cardinality {
return $cardinality;
}
sub _get_row_estimate {
sub get_row_estimate {
my (%args) = @_;
my @required_args = qw(Cxn tbl OptionParser TableParser Quoter);
my ($cxn, $tbl, $o, $tp, $q) = @args{@required_args};
if ( my $where = $o->get('where') ) {
if ( $args{where} ) {
MKDEBUG && _d('WHERE clause, using explain plan for row estimate');
my $table = $q->quote(@{$tbl}{qw(db tbl)});
my $sql = "EXPLAIN SELECT COUNT(*) FROM $table WHERE $where";
my $sql = "EXPLAIN SELECT * FROM $table WHERE $args{where}";
MKDEBUG && _d($sql);
my $expl = $cxn->dbh()->selectrow_hashref($sql);
MKDEBUG && _d(Dumper($expl));