Hi,

For 1. Have a look at the new Teleporter system. 

http://orientdb.com/orientdb-labs/teleporter/
http://orientdb.com/orientdb-teleporter-making-migrations-easier/
http://orientdb.com/docs/last/Teleporter-Home.html

For 2. First thing, although ODB is a No-SQL database, there are always 
gotchas (as with any No-SQL DB) you should be aware of with changing the 
schema (i.e. adding properties on-the-fly, as you'd like). The good news 
is, you can add and remove properties on the fly very easily. The bad news 
is, if you add too many properties on too many records at one time, you 
might cause havoc with the storage engine. Just be aware that No-SQL 
(again, any No-SQL solution, not just ODB) also has limitations in terms of 
flexible schema. Yes, they can offer flexible schema and no, it isn't 
unlimited flexible schema. The good news is, ODB allows you to set up the 
database with larger record size padding (towards the bottom) 
<http://orientdb.com/docs/2.1/plocal-storage-engine.html>, should you know 
you will be going crazy with adding properties. This does mean higher disk 
and I believe even memory requirements, but it also means, available, fast 
and uninterrupted schema changes. That is the compromise you'll have to 
decide on from the start, as the padding settings can't be changed 
on-the-fly (at least I don't believe they can). 

Secondly, OrientDB doesn't currently properly support the avoidance of the 
object/ relational impedance mismatch, because it doesn't allow for 
indexing on non-schema properties. That means, you still always have to 
carry the schema baggage around with you, when developing with ODB, if you 
want ODB to also perform well. (Some hardcore developers believe the DB 
must contain schema. They are still living in the RDBMS world, 
unfortunately...) That being said, ODB tries to support avoiding ORIM in 
ways way beyond any other No-Sql solution, like with the class hierarchy 
system, which is ingenious. Still, this last hurdle of not being able to 
index properties not defined in schema needs to be taken, in order for ODB 
to be a pure No-SQL DB solution IMHO. The good news is, I believe it is 
planned to be added in Version 3.0, which is due to be released sometime at 
the end of this year. Once ODB gets this right, it will be probably the 
most versatile and powerful DB on the planet. :-)

Scott 

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