Thread: SERIAL + PRIMARY KEY = redundant indexes

With current sources:

regression=> create table t1 ( f1 serial primary key );
NOTICE:  CREATE TABLE will create implicit sequence t1_f1_seq for SERIAL column t1.f1
NOTICE:  CREATE TABLE/PRIMARY KEY will create implicit index t1_pkey for table t1
CREATE

OK so far ...

regression=> create table t2 ( f1 serial,
regression-> primary key (f1) );
NOTICE:  CREATE TABLE will create implicit sequence t2_f1_seq for SERIAL column t2.f1
NOTICE:  CREATE TABLE/UNIQUE will create implicit index t2_f1_key for table t2
NOTICE:  CREATE TABLE/PRIMARY KEY will create implicit index t2_pkey for table t2
CREATE

And, indeed, it's made two separate indexes on t2's f1 field.  This is
a bug, no?
        regards, tom lane

> regression=> create table t2 ( f1 serial, primary key (f1) );
> NOTICE:  CREATE TABLE will create implicit sequence t2_f1_seq for SERIAL column t2.f1
> NOTICE:  CREATE TABLE/UNIQUE will create implicit index t2_f1_key for table t2
> NOTICE:  CREATE TABLE/PRIMARY KEY will create implicit index t2_pkey for table t2
> CREATE
> And, indeed, it's made two separate indexes on t2's f1 field.  This is
> a bug, no?

Si. I'll look at it.
                        - Tom

-- 
Thomas Lockhart                lockhart@alumni.caltech.edu
South Pasadena, California

fwiw, there is this comment in the code:
* Note that this code does not currently look for all possible
redundant cases*  and either ignore or stop with warning. The create might fail
later when*  names for indices turn out to be duplicated, or a user might have
specified*  extra useless indices which might hurt performance. - thomas
1997-12-08

But I should (probably) be able to fix this particular case.
                       - Tom

-- 
Thomas Lockhart                lockhart@alumni.caltech.edu
South Pasadena, California