Why is the new database file so much smaller after transfer using native XML?

[Ralph Hains]

Hello,
I've needed to do a full project transfer from a remote database twice now, and as luck (and my poor memory) would have it I did it using "Full Project Transfer via Native XML" the first time and "Full Project Transfer via Connection" the second time. Call them 1.qea and 2.qea. 2.qea is four times bigger than 1.qea and this surprised (and worried) me. I then did another "Full Project Transfer via Native XMI" from 2.qea to give 3.qea and 3.qea is a quarter of the size of 2.qea. I did a project compare between 2.qea and 3.qea to try to see what was missing - but the results were identical. I also did a quick inspection of both models - they look the same to me - and asked each about some baselines - again they seem the same.
I'm at a loss. The EA Help (for the Native XML transfer) says that "Note: This data will not be exported as a part of the Project Transfer: Audit Logs, Image and Image-maps of diagrams, HTML Pages of Linked Documents" but I'm really surprised that this would result in a fourfold decrease. Could it be something to do with past use of replication (the model has "remove replication" greyed so its not current if so)?
Any advice gratefully received. Being defensive/risk averse my gut reaction is to only use the bigger files as they are less likely to have anything missing!
Cheers,
Ralph

[Geert Bellekens]

Did you check the t_snapshot table? (baselines and auditing info)

I can imagine that transfer via native xml doesn't transfer t_snapshot.

Geert

[ea0522]

Did you check the diagram images?
We have configured diagram images to be automatically (re)generated when the diagram changes.
This setting is necessary when using WebEA or Prolaborate as they don't generate diagram images themselves.
These diagram images are also stored in the database (QEA) but not transferred, probably to save bandwidth and they can always be regenerated in the new repository, even in a batch process in the background.

[Ralph Hains]

Did you check the t_snapshot table? (baselines and auditing info)

I can imagine that transfer via native xml doesn't transfer t_snapshot.

Geert

Thank you Geert, I clearly didn't look closely enough at the diff - you are quite right, the t_snapshot table has been cleared. The puzzling thing is that I did "ask" both models whether they had baselines and they both gave the same list - if the smaller file has 0 records in t_snapshot how come it has baselines? Baselines and snapshots are the same thing aren't they, much of the Sparx documentation seems the use the terms interchangeably ("Baselines are snapshots of a repository Package taken at a point in time. These snapshots are stored in a format called XMI"). Opening the smaller file I have just asked about baselines, selected one and ran the diff - this does seem to be working (hasn't finished yet) so presumably the snapshots are still there even when there are no records in  t_snapshot! Cheers Ralph

[Ralph Hains]

Did you check the diagram images?
We have configured diagram images to be automatically (re)generated when the diagram changes.
This setting is necessary when using WebEA or Prolaborate as they don't generate diagram images themselves.
These diagram images are also stored in the database (QEA) but not transferred, probably to save bandwidth and they can always be regenerated in the new repository, even in a batch process in the background.

Thank you - Would you know how I can tell (if one model has diagram images and the other does not), Cheers, Ralph

[ea0522]

Would you know how I can tell (if one model has diagram images and the other does not)

You could try to generate the images in the new (smaller) version and check the sizes of the QEA files again.
The option is reachable via "Settings => Model => Options", tab "Cloud" and button "Create" after "Batch create Diagrams ... cache:".

[Ralph Hains]

Thank you both. I think I can answer my own follow on question to Geert having been searching since - EA doc may well use baseline and snapshot as synonyms but (counter-intuitively), t_snapshot doesn't contain the baselines, t_document does. So t_snapshot just contains the audit info and that is lost transferring by native XML.