Common SQL Tuning Tips and SQL Tuning tuningtips

Source: Internet
Author: User

Common SQL Tuning Tips and SQL Tuning tuningtips

 

  • Create an appropriate index (refer to correct database index creation)
  • Replace OR with UNION (applicable to index columns)
  • Replace in and not in with exist and not exist
  • Do not declare numbers in character format (this will invalidate the index and generate a full table scan)
  • Do not use select * (list each column after select)
  • Do not perform computation in JOIN and WHERE clauses (use a new column in the table to store the calculated values in advance)
  • Avoid using is null and is not null in the index column.
  • Use placeholders for NULL columns as much as possible.

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