Thomas Kellerer, 25.06.2010 14:32:
Wang, Mary Y, 25.06.2010 01:04:
Hi,
I'm trying to find some write-ups about the differences between Postgres
and MySql. A lot of stuff showed up on Google, but most of them are old.
I saw this wiki over here
http://wiki.postgresql.org/wiki/Why_PostgreSQL_Instead_of_MySQL_2009 and
plan to watch a recent webcast on PostgreSQL vs. MySQL that was offered
by EnterpriseDB.
Are there any other most recent summaries on the differences between
Postgres and MySql?
Thanks in advance
Mary
My favorite features in Postgres that MySQL doesn't have
- deferrable constraints
- sequences
- check constraints
- windowing functions
- recursive common table expressions
- the absence of a program to check the consistency of the data
- the ability to use a subselect in a DML statement that references the
table to be updated
- generate_series()
- array handling
And another thing:
The following works in Postgres (and Oracle, DB2, SQL Server, Derby) but not in
MySQL (using InnoDB):
create table fktest (
id integer primary key not null,
name varchar(20),
parent_id integer
);
alter table fktest add constraint fktest_parent foreign key (parent_id)
references fktest(id);
insert into fktest (id,name,parent_id) values (1,'Root', null);
insert into fktest (id,name,parent_id) values (2,'Sub1', 1);
insert into fktest (id,name,parent_id) values (3,'Subsub', 2);
insert into fktest (id,name,parent_id) values (4,'Sub2', 1);
commit;
delete from fktest where id in (1,2,3,4);
commit;
MySQL complains that it cannot delete the rows"Cannot delete or update a parent row:
a foreign key constraint fails"
Regards
Thomas
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