modify migration, statistics table value row changed to bignum
use postgresql
use database.yml
remove debug output
reconstruction database
add model, refactoring batch scripts, modify migration
add test
modify typo
fix typo
fix reference miss
return total ranking
improvement total ranking pefromance
implement daily ranking and featured ranking
modify total ranking page
modify daily ranking page
modify featured ranking page
modify search page
modify test
modify gem page
rename variables