Performance improvements in django-data-migration 0.2.0

gistfile1.txt

This includes some small benchmark results for the preformance improvements introduced in
django-data-migration 0.20. The migrations are from the blog-testapp which is included in
the repo, only updated to use real data.

############# FOR AUTHOR, COMMENTS

# WITHOUT PREFETCH
» time ./manage.py migrate_this_shit
Migrating <class 'blog.data_migration_spec.AuthorMigration'>
Migrating element 2961/2961
Migrating <class 'blog.data_migration_spec.CommentMigration'>
Migrating element 105283/105283

./manage.py migrate_this_shit   235,20s user 7,34s system 98% cpu 4:05,84 total

# WITH PREFETCH
» time ./manage.py migrate_this_shit
Migrating <class 'blog.data_migration_spec.AuthorMigration'>
Migrating element 2961/2961
Migrating <class 'blog.data_migration_spec.CommentMigration'>
Migrating element 105283/105283

./manage.py migrate_this_shit  178,53s user 6,79s system 98% cpu 3:08,56 total

>>>> Speedup = 1,320224719


############ FOR POST

# WITHOUT PREFETCH
» time ./manage.py migrate_this_shit
Migrating <class 'blog.data_migration_spec.PostMigration'>
Migrating element 32030/32030

./manage.py migrate_this_shit  166,90s user 5,21s system 96% cpu 2:57,92 total

# WITH PREFETCH
» time ./manage.py migrate_this_shit
Migrating <class 'blog.data_migration_spec.PostMigration'>
Migrating element 32030/32030

./manage.py migrate_this_shit  92,02s user 3,66s system 97% cpu 1:37,67 total

>>>> Speedup = 1,804347826