Tuesday, July 23, 2013

Redshift schema migration


Indexes, foreign keys, primary keys, and arrays are not supported in Redshift. The distribution key, which determines how your data is distributed across the cluster, is a very important part of the schema definition. Check all queries for the table and choose the column that gets joined most frequently for the distribution key to get the best performance. You can only specify one distribution key and if you are joining against multiple columns on a large scale, you might notice a performance degradation. Also, specify the columns your range queries use the most as sort key on your table (can be multi columns in sort key), as it will help with the performance.

2 comments:

  1. Great and really appreciable Post. Cloud migration will help in transferring data easily from one place to another. Share more ideas on Cloud Migration and cloud computing.

    ReplyDelete
  2. Adata mart is a sub-set of data in a data warehouse that is optimized for a specific area of business. Because data marts allow for the rapid access of data, they are used for business-critical applications, such as data mining and data analysis. A data mart can be used to track sales, inventory or customers. For example, a common data mart is an inventory data mart. This data mart contains all of the items in a particular warehouse inventory, and details about when the items were shipped, to whom and when.

    ReplyDelete