Re: Postgresql:MySQL = BSD:Linux ?

[Arun Sharma <adsharma@xxxxxxxxxxxxxxx>]

On Thu, Jun 29, 2000 at 05:26:33PM +0530, Chandrashekhar Bhosle wrote:
> 
> On Wed, 28 Jun 2000, Arun Sharma wrote:
> 
> > Add Interbase to the mix and the fact that MySQL doesn't do transactions,
> > it gets pretty interesting :)
> 
> MySQL does transactions. It's in the 2.3 (devel) releases.

Do you have a pointer to what percentage of transactions has been 
actually implemented ?

Read: http://openacs.org/why-not-mysql.html , but take it with a grain
of salt. I liked this comment:

    After investigating the matter it has become clear to me that MySQL
    is not an ordinary relational database but a key element in a plot
    being hatched by a global conspiracy of Communists, Homosexuals and
    Ethnic Minorites.

    Thank you. 

    -- Michael Ellis, June 13, 2000

> 
> Do Free/Net/Open BSD have a journalling filesystem?

No but they support softupdates, which became free last week, previously
it was available, but for non-commercial use only.

There is an accompanying USENIX paper, also presented last week,
which tries to argue that softupdates might be a better approach than
journalling. See my posts in the last week for the link.

The difference is - do you want to rollback the transaction and go to
a consistent state (this is the approach journalling takes). It may
make sense for databases. Does it make sense for filesystems ?

Softupdates doesn't try to do transactions, but ensures that the 
filesystem is always in a usable state. Example: when you rename 
file a to b, journalling ensures that you see file a or b, but not
both. Softupdates might result in having both a and b. But do you
really care ?

They both achieve the same results (short fsck times), but have different
overheads.

	-Arun