Performance difference between char and int2 columns

hi everybody.

i have two table as :

CREATE TABLE "public"."tb_section_phones" (
"section_id" INTEGER NOT NULL,
"ptype_id" INTEGER NOT NULL,
"country_code" SMALLINT DEFAULT 90,
"domain_code" SMALLINT,
"number" CHAR(7) NOT NULL,
"extension" VARCHAR(6),
CONSTRAINT "tb_section_phones_fk" FOREIGN KEY ("section_id")
REFERENCES "public"."tb_sections"("sect_id")
ON DELETE CASCADE
ON UPDATE CASCADE
NOT DEFERRABLE,
CONSTRAINT "tb_section_phones_fk1" FOREIGN KEY ("ptype_id")
REFERENCES "public"."tb_phone_types"("ptype_id")
ON DELETE CASCADE
ON UPDATE CASCADE
NOT DEFERRABLE
) WITHOUT OIDS;

CREATE TABLE "public"."tb_section_phones_temp" (
"sect_id" INTEGER NOT NULL,
"ptype_id" INTEGER NOT NULL,
"country_code" CHAR(2) DEFAULT 90,
"domain_code" CHAR(3),
"number" CHAR(7) NOT NULL,
"extension" VARCHAR(6),
CONSTRAINT "tb_section_phones_fk" FOREIGN KEY ("sect_id")
REFERENCES "public"."tb_sections"("sect_id")
ON DELETE CASCADE
ON UPDATE CASCADE
NOT DEFERRABLE,
CONSTRAINT "tb_section_phones_fk2" FOREIGN KEY ("ptype_id")
REFERENCES "public"."tb_phone_types"("ptype_id")
ON DELETE CASCADE
ON UPDATE CASCADE
NOT DEFERRABLE
) WITHOUT OIDS;

the differences between two table are :
in the first table country_code type is smallint, in the second table
char(2)
in the first table domain_code type is smallint, in the second table char(3)
.

The problem is that:
my both table has 10 records.
when i run this query on first table :
select * from tb_section_phones;
it lasts 0.02 sec.
when i run this query on second table :
select * from tb_section_phones_temp;
it lasts 0.13 sec.

6.5 times slower.
why so performance difference?
should i prefer int as column type?

thanks in advance.