[Info-vax] Databases versus RMS

[Phillip Helbig---undress to reply]

In article <jmqv2n$9f5$1 at news.albasani.net>, Jan-Erik Soderholm
<jan-erik.soderholm at telia.com> writes: 

> The DECs SSD in SSB's (StorageWorks disks) was RAM based as far as I know.
> That is, did not retain data at power loss. Was often used as one part
> of a schadow-set so that all reads was doen from the RAM disks and all
> writes went to both (and thus stored permanently).

I have a couple and they do retain their contents.  I assume they write 
the contents to disk when "spinning down" and/or when the power goes 
off.  EZ32: 268 MB.

> Modern SSD (Solid State Disks) are more or less always Flash-based and
> thus retain data at a power loss. Many uses a Flash SSD as their only
> disks in theirs laptop replacing the original rotating hard disk.

Right.  Also, the iPad has this as its "disks" (in addition to RAM).  
The flash disks are fine for some things but with lots of I/O they die 
pretty quickly (even after a few hours for really intensive I/O 
operations) while a conventional disk can last for years.