In addition to Weibo, there is also WeChat
Please pay attention
WeChat public account
Shulou
2025-01-17 Update From: SLTechnology News&Howtos shulou NAV: SLTechnology News&Howtos > Database >
Share
Shulou(Shulou.com)06/01 Report--
Projection push-down
Through the above conversion, the number of tuples before connection and the fields involved in the operation are reduced to achieve the purpose of optimization. IV. Summary
1. Equivalence rules: relational algebraic expressions can be transformed according to equivalence rules.
2. Optimization: the expression can be rewritten into a better equivalent expression through the equivalence rule.
V. reference
Wikipedia
Database system concept
Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.
Views: 0
*The comments in the above article only represent the author's personal views and do not represent the views and positions of this website. If you have more insights, please feel free to contribute and share.
Continue with the installation of the previous hadoop.First, install zookooper1. Decompress zookoope
"Every 5-10 years, there's a rare product, a really special, very unusual product that's the most un
© 2024 shulou.com SLNews company. All rights reserved.
12
Report
