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SQL for data scientists in 100 queries (gvwilson.github.io)

834 points by Anon84 · 924 days ago · 158 comments on HN

Article summary

The article discusses SQL for data scientists in 100 queries, but its content is not available. The discussion revolves around learning resources and best practices for SQL. Commenters share their favorite SQL tutorials and discuss various aspects of SQL, including joins, query optimization, and data manipulation. The conversation also touches on the importance of practice and real-world experience in mastering SQL.

Main themes

  • SQL tutorials and resources
  • Joins and query optimization
  • Database compliance and features
  • Data manipulation and analysis
  • Query performance and optimization
  • SQL best practices and real-world experience

What commenters say

  • Temporary tables are not always stored in memory, but rather are connection-specific and may be optimized for throwaway use.
  • Non-equi joins, also known as timeseries joins, can be challenging to work with, especially when dealing with timestamp-based data.
  • ClickHouse is not fully SQL-compliant and lacks certain features, such as basic cursor support and transactions.
  • The definition of left outer joins can be misleading if it implies a simple matching process, rather than accounting for row multiplication and complex join conditions.
  • Some databases, like PostgreSQL, support most major SQL features, while others, like ClickHouse, have limitations.
  • Query optimization is crucial for performance, and techniques like breaking up complex queries and using window functions can be effective.
  • ChatGPT and other language models can be helpful in generating and testing SQL queries, especially for complex tasks like JSON column migrations.