How can we use MongoDb with postgresql?

Is char(1) really use one byte space in postgresql?

• Hello guys:  I am a newbie to PostgreSQL database. I meet a problem when using PostgreSQL database. In the document http://www.postgresql.org/docs/9.1/interactive/datatype-character.html It's said that "char" use single-byte. Here is my test: CREATE TABLE test (text char(1)); and then I use: insert into test (test) values ('â–¶'); (â–¶ is a special char who's utf8 decode is 9654 (base 10).) It carried out perfect. And I use: SELECT * from test;  test ------  â–¶ (1 row) How can single-byte store â–¶ ? (PostgreSQL 9.1.9 on x86-64 Debian 7 OS)

• Answer:

  From the link you posted (emphasis mine) SQL defines two primary character types: character varying(n) and character(n), where n is a positive integer. Both of these types can store strings up to n characters (not bytes) in length. ... The notations varchar(n) and char(n) are aliases for character varying(n) and character(n), respectively. character without length specifier is equivalent to character(1).