ruby on rails - Overwriting data to the model -

i using reading table oracle , writing data model using cronjob everymidnight me caching data , enhance speed. using create method writing data in model create new entries , duplicate data in model everytime. there method in model update data or overwrite?

  model.each |model|       p = model.create model.attributes       p.save     end 

why want save models? won't caching. should instead profile application , implement caching techniques memcached.

but anyways here's code read table:

model.each {|model| model.new model.attributes } 

update according clarification: copying 1 db without duplication done (given model1 accesses source db , model2 access destination db):

model1.each |model1|   model2 = model2.find_or_initialize_by_id model1.id, model1.attributes   model2.save! } 

this won't handle deletions, however. may still want memcached , maybe database sharding. may worth thinking master/slave replication on database level "slow" database master (all database writes go this) , slave "fast" database (all read go this). web applications read bound, in case. rails has support this, see newrelic's scaling rails screencast series scaling databases.