postgresql - ポストグル。plpgsql スタックの深さ制限を超えました

Question

テーブルから何かを自動的に更新する単純な関数に取り組んでいます。

create or replace function total() 
returns void as $$
declare
  sum int;
begin
  sum = (SELECT count(copy_id) FROM copies);
    update totalbooks
    set all_books = sum
    where num = 1;
  end;
$$ language plpgsql;

「select total();」を実行すると それは完全に正常に動作するので、自動的に更新されるように関数トリガーを作成しました:

create or replace function total1() returns trigger as $$
begin
   perform (select total());
    return null;
end;
$$ language plpgsql;

しかし、これを実行した後：

create trigger total2
after update
on totalbooks
for each row
execute procedure total1();

エラーメッセージが表示されます：

ERROR:  stack depth limit exceeded
HINT:  Increase the configuration parameter "max_stack_depth" (currently 3072kB), after   ensuring the platform's stack depth limit is adequate.
CONTEXT:  SQL statement "SELECT (SELECT count(copy_id) FROM copies)"
PL/pgSQL function total() line 5 at assignment
SQL statement "SELECT (select total())"
PL/pgSQL function total1() line 3 at PERFORM
SQL statement "update totalbooks
set all_books = sum
where num = 1"
PL/pgSQL function total() line 6 at SQL statement
SQL statement "SELECT (select total())"
PL/pgSQL function total1() line 3 at PERFORM
SQL statement "update totalbooks
set all_books = sum
where num = 1"
PL/pgSQL function total() line 6 at SQL statement
SQL statement "SELECT (select total())"
PL/pgSQL function total1() line 3 at PERFORM
SQL statement "update totalbooks
set all_books = sum
where num = 1"
PL/pgSQL function total() line 6 at SQL statement
SQL statement "SELECT (select total())"
PL/pgSQL function total1() line 3 at PERFORM
SQL statement "update totalbooks
set all_books = sum
where num = 1"
PL/pgSQL function total() line 6 at SQL statement
SQL statement "SELECT (select total())"
PL/pgSQL function total1() line 3 at PERFORM
SQL statement "update totalbooks
set all_books = sum
where num = 1"
PL/pgSQL function total() line 6 at SQL statement
SQL statement "SELECT (select total())"
PL/pgSQL function total1() line 3 at PERFORM
SQL statement "update totalbooks
set all_books = sum
where num = 1"
PL/pgSQL function total() line 6 at SQL statement
SQL statement "SELECT (select total())"

明らかに、トリガーに問題があります。助けてください。

Visual C++ビルド1600、64ビットでコンパイルされたPostgres 9.2.4を使用しています

編集：

pg_trigger_depth() を試しましたが、トリガーが自動的に更新されませんか?? 「select total()」を実行する必要があります

ここに私の新しいコードがあります:

create or replace function total() 
returns void as $$
declare
  sum int;
begin
   sum = (SELECT count(copy_id) FROM copies);
    update totalbooks
    set all_books = sum;
end;
$$ language plpgsql;


create or replace function total1() returns trigger as $$
begin
  perform (select total());
  return null;
end;
$$ language plpgsql;

create trigger total2
after update
on totalbooks
for each row
WHEN (pg_trigger_depth()=0)
execute procedure total1();