Why isn't ACID PostgreSQL offered by host instead of mySQL?

Especially for e-commerce sites!

[stlouislouis]

Hi,

I've seldom seen PostgreSQL offered by host. It's
almost always mySQL that's offered.

Why? What are the disadvantages of offering
PostgreSQL for hosting clients?

It seems that *especially* for e-commerce sites
an ACID compliant database like PostgreSQL would
be much more appropriate than mySQL.

Thanks for sharing (and not engaring in a
PostgreSQL .vs mySQL religious war flame fest),

Louis

P.S. For those unfamiliar with the term, ACID
stands for atomicity, consistency, isolation and
durability. Basically:

Atomicity means that all the database changes
making up a transaction (i.e. buy product) are
either all committed to the database or all
rolled back.

Consistency means that a database's "state" goes
from one valid state to another. In practice this
means SQL statements that would violate logical
dependency or referrential integrety rules are not
allowed/executed by the database.

Isolation means that the result of one transaction
(i.e. each and every database change for transaction
"A") does not appear or exist *at all* to any other
transaction until transaction "A" is complete and
commited to the database.

Durability means that a successfully committed
transaction is permanant and will survive a
systems failure (within reason, of course!).

[scotty]

From my own experience, PostgreSQL is more difficult to set up, comparing to MySQL. MySQL has quite a nice user authentication model as well. It is also more difficult to do a live backup of a PostgreSQL database - you need to either shut it down first, or do a dump. At the end, it might cost the ISP more to support PostgreSQL. And if you are willing to pay more, you probably can get SQL Server or something more "enterprise".

You still can "simulate" a translation using MySQL, but knowing all your UPDATE, INSERT and DELETEs can be rollback in the middle of bad coding is nice.