[ZODB-Dev] Newbie ZODB Questions

[Chris Withers]

Jennifer Flake wrote:
> 
> (1) In order to do a backup of the entire database, aside from Data.fs,
> what do I have to backup?

If you're using FileStorage, which you are ;-), then nothing. Just that file
will suffice.

> (2) Can I move my backup from one platform to another (take a backup
> from a Linux server and move it to a Solaris server) and recover my
> data?

Yes

> (3) I did a some reading and saw that the Data.fs is a file where
> transactions are appended.  Where does the rest of the object data exist
> and is that data in a platform independent format?  If not, is there a
> way to get the data out in platform-independent way?

All data is stored in Data.fs with file storage.

> (4) Is there any way to perform adhoc queries on ZODB?

Depends what you mean by adhoc and query ;-)

> (5) Is ZODB scalable? Would it be possible to store 10 gb of data
> without suffering performance issues?

Yes, Yes

> (6) Is RAID the only way to implement redundancy for ZODB?

There is a ReplicatedStorage, but it smells like an alpha

> (7) Is there a way to replicate data from one ZODB to another?

Yes, .zexp's or xml-rpc using Andy McKay's ZSyncher

> (8) Where do the application usernames/passwords physically exist in
> Zope?

In Data.fs. Encryption for this is currently beign experimented with.

> (9) How often does Data.fs file corruption occur?

Hardly ever.

> (10) How does the rollback of a transaction work? (do I have to rollback
> all of the transactions that occur after the transaction that I want to
> rollback, too)?

Only if they modified something that was modified in the transaction you want to
roll back.

> (11) If I am "reading" an object, do I continue to get a read-consistent
> view of it, even if someone else performs a write to it, while I am
> reading it?

Yes. I think. In Zope, certainly...

> (12) If my server slams down from a power outage, will Zope be able to
> recover itself gracefully when I restart it?

Yes.

Chris