ian-whitestone

Presto Specific

• Don’t SELECT *, Specify explicit column names (columnar store)
• Avoid large JOINs (filter each table first)
  • In PRESTO tables are joined in the order they are listed!!
  • Join small tables earlier in the plan and leave larger fact tables to the end
  • Avoid cross joins or 1 to many joins as these can degrade performance
• Order by and group by take time
  • only use order by in subqueries if it is really necessary
• When using GROUP BY, order the columns by the highest cardinality (that is, most number of unique values) to the lowest.

staltz

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

---

This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

---