[Info-vax] VMS and the (lack of the) TRIM facility.

[David Froble]

Jan-Erik Soderholm wrote:
> johnwallace4 at yahoo.co.uk skrev den 2015-06-20 13:30:

>> But isn't the enterprise-class fashion this week to put everything
>> in main memory, SAP HANA style?
> 
> I must confess that I don't realy understand this "memory database"
> and "HANA" fuzz. Looking right now (355 days of database beeing "open")
> we have a little more then 99.7% memory hits when looking for some
> database page in our Rdb database. The rest 0.3% are read from disk
> and these 0.3% are mainly from the nighly batch runs. During normal
> work we more or less run "in memory". Besides of the usual log
> file write and such, but that is the same for HANA anyway...

Jan-Erik, I must observe that you are not a marketing person.

Yes, as with many other things, using memory in better ways as more 
becomes available is just another development.  A good development. 
Sort of how things just work.

But, what is the perspective of a marketing person.  "Hey, look at this 
new idea, let's use it to sell more <stuff>."  Yes, that is their job. 
But for those involved, the marketing people sometimes are the last to 
"get a clue".  Doesn't bother them very much.  They just proceed with 
the perception that they have just done something great.  Watch out for 
your wallet.

Since the advent of decent caching on VMS, in what, V7.2 or V7.3, just 
about all of the commonly used data in our customer systems is sitting 
in cache.  Don't really need anything else.  Certainly not the claims of 
the people saying "hey, look at this".  Like you, we just use what's 
there and see great performance.  For anyone who doesn't believe that, 
we can turn off caching and watch the system act like it's just run into 
a bunch of cold molasses.

:-)

On the other hand I have a few times seen some marketing people who try 
to come up with new ideas, and every once in a while they come up with a 
gem.