Amazon Glacier provides three different types of retrieval options that range from a few minutes to hours. The retrieval options available are:

• Expedited: This is the fastest retrieval job, customers need to wait 1-5 minutes to have data available and this can be done OnDemand and Provisioned
• Standard: This is the default option where the job completes in 3 to 5 hours
• Bulk: This job will retrieve any volume of information with the lowest cost, but you will need to wait 5-12 hours

You have the option to only retrieve a subset of a large object using SQL. This feature is called Glacier Select where you can read the bytes you need.