Emi Lu wrote:
Greetings,
If one column "col1" is defined as :
col1 varchar(1) not null default ''
Does it means that col1's definition is equal to
col1 char(1) not null default ''
Not quite; for example,
neilc=# create table t1 (x char(1) not null);
CREATE TABLE
neilc=# create table t2 (x varchar(1) not null);
CREATE TABLE
neilc=# insert into t1 values ('');
INSERT 0 1
neilc=# insert into t2 values ('');
INSERT 0 1
neilc=# select octet_length(x) from t1;
octet_length
--------------
1
(1 row)
neilc=# select octet_length(x) from t2;
octet_length
--------------
0
(1 row)
Put it another way, will char '' be saved as char(1) or char '' does not
use space at all?
I'm not sure what you mean.
-Neil
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