Topic outline

• Enhancing Query Performance with the SQL Optimizer

  Enhancing Query Performance with the SQL Optimizer

  Content Type
  Video

  Duration
  35m

  Level
  Introductory

  Learn how the InterSystems IRIS® data platform SQL optimizer leverages advanced statistics, smart caching, and automation to deliver efficient query processing. See how query plans are developed and selected, and how the features of the SQL optimizer facilitate the process of creating smart and efficient plans.

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• Code Used in This Video

  Code Used in This Video

  Reference	Timestamp	Code
  Query that selects all customers who live in New York City, with the zip code 10019	3:55	SELECT * FROM cust WHERE ZIP = '10019'
  Query that selects all male customers who live in the zip code 10019	6:55	SELECT * FROM cust WHERE ZIP = '10019' AND Gender='M'
  Query where the literals have been substituted with tokens	16:00	SELECT TOP ? * FROM cust WHERE ZIP = ? AND DOB < TO_DATE( ? , ? )
  Example of a query where outliers may affect the query plan	29:13	… FROM log WHERE level = 'INFO'
  Example of a query where range selectivity may affect the query plan	29:25	… FROM log WHERE dt > '5/5/22'
  Example of a query where truth conditions may affect the query plan	29:45	… FROM log WHERE ( 1 = 0 AND ... )
• What's Next?

  What's Next?

  • Read about interpreting query plans (documentation, 25m).
  • See how to find and fix slow queries (video, 9m).