trans device and data device

trans device and data device

Post by Stephan Wit » Wed, 28 Mar 2001 02:42:11



Howdy,

I'm filling in til our new database person arrives in a month or so,
forgive me if this is in the FAQ somewhere. Using ASE 11.5.1 on an
NT 4.0 box, I'm trying to modify a database so that its transaction
device is on one hard drive and its data device is on another.

To do this, I:
1) back it up with dump database
2) create a new database with devices where I want them
3) restore it with load database

So far so good, except that half of the data device is now marked
as being used for transaction log. WTF? Did I miss something here?

--
|  "I used to be with `it', but then they changed what `it' was.  |
|   now what I'm with isn't `it', and what `it' is is weird and   |

 
 
 

trans device and data device

Post by Bret Halfor » Wed, 28 Mar 2001 04:26:54


Yes.  When you create a database for load, you have to use the same
order and
size of segments that the database you are loading had (although you can

change the devices).

If your original database was organized with 20mb of data followed by 10
mb of log
followed by 25 mb  of data, that is the same order you need to create
the db for load.
You can certainly put each fragment on a different device, and even
split a fragment
and put pieces on different devices, but the size and order of the
segments will remain the
same.

If you run

select segmap, size/512 as "mb" from sysusages where dbid = <x> order by
lstart

It pretty much tells you the size and order to use in your create
database statement.
segmap 3 = data, 4 = log, 7 = mixed data and log, anything higher
indicates user-defined
segments.

-bret


> Howdy,

> I'm filling in til our new database person arrives in a month or so,
> forgive me if this is in the FAQ somewhere. Using ASE 11.5.1 on an
> NT 4.0 box, I'm trying to modify a database so that its transaction
> device is on one hard drive and its data device is on another.

> To do this, I:
> 1) back it up with dump database
> 2) create a new database with devices where I want them
> 3) restore it with load database

> So far so good, except that half of the data device is now marked
> as being used for transaction log. WTF? Did I miss something here?

> --
> |  "I used to be with `it', but then they changed what `it' was.  |
> |   now what I'm with isn't `it', and what `it' is is weird and   |