Redshift

1. AWS RedShift is a fast petabyte scale data warehouse service on the cloud
2. OLAP vs OLTP
   1. OLTP is online transaction processing. Use RDS for OLTP. More writes less reads. Example:  E-commerce website with Shopping Cart
   2. OLAP is online analytical processing.
      1. Few writes and many many reads especially those that aggregate an entire column based on conditions.
      2. Example: Query for Sum of all sales in January across all states in the south region.
3. RedShift uses columnar database
   1. Data is sequentially stored by column on the disk as opposed to by row as in case of RDS/OLTP
   2. Suitable for aggregates across all records in a single column
   3. Suitable for compression since all data in a particular column have data of same type
4. Configuration of AWS RedShift
   1. Start with single node (max size 160 GB)
   2. You can upgrade to Multi node as your needs grow:
      1. Leader node: manages client connections. Front end t receive queries.
      2. Compute nodes: Stores data, computes queries. Up to 128 compute nodes can be deployed.
      3. Massively Parallel Processing (MPP) via distribution loads across many compute nodes that run parallelly
5. Pricing
   1. No charges for leader node
   2. Compute nodes are charged per hour per node
   3. Backups are charged
   4. Data transfer is measured and charged
6. Availability
   1. Available in single AZ (availability is not very important since OLAP systems are only used by few managers)
   2. You can take snapshots and restore to other AZs if needed