What is the most efficient way to write 3GB of data to datastore?
If you need to store each row as a separate entity, it does not matter how you create these entities - you can improve the performance by batching your requests, but it won't affect the costs.
The costs depend on how many indexed properties you have in each entity. Make sure that you only index the properties that you need to be indexed.
I have a 3Gb csv file. I would like to write all of the data to GAE datastore. I have tried reading the file row by row and then posting the data to my app, but I can only create around 1000 new entities before I exceed the free tier and start to incur pretty hefty costs. What is the most efficient / cost effective way to upload this data to datastore?