8/26/2023 0 Comments Distribution key redshift![]() For more information, see Amazon Redshift and PostgreSQL JDBC and ODBC. For information about important differences between Amazon Redshift SQL and PostgreSQL, see Amazon Redshift and PostgreSQL.Īmazon Redshift communicates with client applications by using industry-standard PostgreSQL JDBC and ODBC drivers. Amazon Redshift is based on industry-standard PostgreSQL, so most existing SQL client applications will work with only minimal changes. This section introduces the elements of the Amazon Redshift data warehouse architecture as shown in the following figure.Īmazon Redshift integrates with various data loading and ETL (extract, transform, and load) tools and business intelligence (BI) reporting, data mining, and analytics tools. This section presents an introduction to the Amazon Redshift system architecture. When you execute analytic queries, you are retrieving, comparing, and evaluating large amounts of data in multiple-stage operations to produce a final result.Īmazon Redshift achieves efficient storage and optimum query performance through a combination of massively parallel processing, columnar data storage, and very efficient, targeted data compression encoding schemes. Using Amazon Redshift with Other ServicesĪn Amazon Redshift data warehouse is an enterprise-class relational database query and management system.Īmazon Redshift supports client connections with many types of applications, including business intelligence (BI), reporting, data, and analytics tools.Internal Architecture and System Operation.It will have the reverse effect and worsen the performance of the query (the query engine can’t use the full potential of the sort keys if they are compressed) Redshift even offers a function that will analyze your data and recommend the best compression to use.ĭo not use compression on the sort keys. It will reduce the space occupied by the data which will ultimately improve query performance (it reduces the required disk I/O and amount of data sent on the network). When creating your schema, don’t forget to include a compression type for your columns. The ALL distribution style will greatly increase the space required, load time, and maintenance work for the same data.Watch out for those DISTSTYLE ALL (this one is not about dist key, but it’s close enough).This means that the data for both tables will be on the same node, and queries on this data will not be transferred between nodes.If some tables are often joined together, they should have the same dist key.It should result in an even distribution, so something like a UUID is a good choice.There are a couple of things to keep in mind when choosing a dist key: Sort k … ok, I’m kidding -> dist keysĭist keys will determine how the data of a table is distributed, or split, accross the nodes of the cluster. Also, if you decided to use a compound sort key, keep in mind that queries that are not filtering on the first column specified in the sort key will not use the other columns, even if they are included in the WHERE clause of the query. Make sure to always (or as often as possible) use the column(s) of the sort key in the WHERE clauses of a query (and that means even in the sub and sub sub queries), otherwise your cluster will waste a lot of resources scanning unnecessary data. I can’t stress enough how important sort keys are, so I decided to talk about them again. There are a lot of good guides and documentation on this subject, so be sure to check them out! Sort keys… always and forever It is very important to choose the good sort key. ![]() It will skip entire data blocks by only looking at the min and max value of the sort key for this block. The Redshift query engine will use it to optimize the queries. Basically, a sort key determines which column(s) will be used to order the rows. This one is pretty simple: every table in a cluster should have a sort key. Here are some of the tips, tricks, and overall best practices we gathered during those years. We were early adopters of this data warehousing solution and while it is an awesome product today, I probably don’t need to tell you that we hit some bumps along the way. This solution is based on AWS Redshift, a petabyte scale columnar store. Over the last 4 years, I have been part of the team that builds the Usage Analytics solution here at Coveo.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |