DB<91> use Data::Dump qw/pp/ 

  DB<92> ; {local @hash{qw/log schema/};say pp \%hash}; say pp \%hash
{ a => 1, b => 2, c => 3, log => undef, schema => undef }
{ a => 1, b => 2, c => 3, log => "l", schema => "s" }                                                                      

##</code><code>##

  DB<96>  say pp do {delete local @hash{qw/log schema/}; %hash }; say pp \%hash
("a", 1, "c", 3, "b", 2)
{ a => 1, b => 2, c => 3, log => "l", schema => "s" }

  DB<97>  say pp do {delete local @hash{qw/log schema/}; +{%hash} }; say pp \%hash
{ a => 1, b => 2, c => 3 }
{ a => 1, b => 2, c => 3, log => "l", schema => "s" }

  DB<98> 

##</code><code>##

  DB<99> ; {delete local @hash{qw/log schema/};say pp \%hash}; say pp \%hash
{ a => 1, b => 2, c => 3 }
{ a => 1, b => 2, c => 3, log => "l", schema => "s" }

  DB<100>