Hang while commiting objects with attribute as MagmaCollection+index

[Hilaire Fernandes]

While writing test I met the following problem:
I want to add hundred of (learner) object in a users MagmaCollection (it 
is located in a branch of the DB and it has index too)

While looping, the commit becomes slower and slower until Squeak stall 
at the 90th iteration. I know I can move the commit: in the outer block, 
it is faster but still hang at the final commit time. The mouse icon is 
then stuck to the write icon and the Squeak has to be brutally stopped.

In the Learner initialization if I remove the addIndex:, the process run 
at a constant speed and finish.
It looks like a problem related to index creation.

testAddLearner
| user |
100 timesRepeat:
    [user := IFILearner new.
     IFIDbSession commit:
	[IFIModels users add: user
	"IFIMagmaResource current school addPerson: user"]]
self assert: IFIMagmaResource current school learners size = 100


IFILearner>>initialize
	super initialize.
	schoolYear := #CE2.
	learningStates := MagmaCollection new.
	learningStates
		"addIndex: (MaCompetencyIndex attribute: #competency);"
		addIndex: (MaFloatIndex attribute: #acquisitionLevel)