Performance

The data used in the metrics is that of what would be considered a fairly standard application in MongoDB that Mongoid could manage.

1,000,000 documents in the main collection
10,000 embedded documents on a root document (1-n)
10,000 embedded documents on a root document (1-1)
100,000 referenced documents to another collection (1-n)
100,000 referenced documents to another collection (1-1)
10,000 referenced documents to another collection (n-n)

• Performance metrics done on a 2.93 GHz i7 iMac / 8GB RAM, OSX 10.7, Mongoid 2.2.0

• The script to run the performance metrics can be found here. Notes

Many to many relations are not recommended for over 10,000 documents when using MRI due to the garbage collector taking over 90% of the run time when calling #build or #create. This is due to the large array appending occuring in these operations. When performing appends to one to many relations we execute in batch (appending all at once instead of one at a time) due to the slow performance of MongoDB’s $push atomic operator. Operation Time Ops/sec root (1,000,000 operations) Model#create 417.93 2,392 Model#all.each 40.87 24,476 Model#find 0.001 Model#save 487.93 2,049 Model#update_attribute 339.54 2,945 embedded 1-n (10,000 operations) relation#build 2.253 4,438 relation#clear 1.230 8,130 relation#create 4.899 2,041 relation#count 0.011 relation#delete_all 1.377 7,262 relation#push (batch) 3.496 2,860 relation#each 0.027 370,370 relation#find 0.044 relation#delete 0.045 embedded 1-1 (10,000 operations) relation#= 3.902 2,562 relational 1-n (100,000 operations) relation#build 18.521 5,399 relation#clear 4.085 24,479 relation#create 45.464 2,199 relation#count 0.051 relation#delete_all 5.596 17,869 relation#push (batch) 34.551 2,894 relation#each 0.055 1,818,181 relation#find 0.020 relation#delete 0.410 relational 1-1 (100,000 operations) relation#= 54.991 1,818 relational n-n (10,000 operations) relation#build 1.325 7,547 relation#clear 0.350 28,571 relation#count 0.001 relation#delete_all 0.001 10,000,000 relation#push (batch) 2.628 3,805 relation#each 0.005 2,000,000 relation#find 0.010 relation#delete 0.060 eager loading 1-1 (10,000 docs) Model#each (without eager load) 5.617 1,780 Model#includes (with eager load) 2.966 3,371 eager loading 1-n (10,000 docs) Model.all#each (without eager load) 4.300 2,325 Model#includes (with eager load) 2.094 4,775