MySQL – why not index every field?

by

Indexes take up space in memory (RAM); Too many or too large of indexes and the DB is going to have to be swapping them to and from the disk. They also increase insert and delete time (each index must be updated for every piece of data inserted/deleted/updated).

You don’t have infinite memory. Making it so all indexes fit in RAM = good.

You don’t have infinite time. Indexing only the columns you need indexed minimizes the insert/delete/update performance hit.

More Related Contents:

  1. Mysql::Error: Specified key was too long; max key length is 1000 bytes
  2. Mysql Improve Search Performance with wildcards (%%)
  3. Mysql covering vs composite vs column index
  4. Does Order of Fields of Multi-Column Index in MySQL Matter
  5. Does a UNIQUE constraint automatically create an INDEX on the field(s)?
  6. MySQL optimizing INSERT speed being slowed down because of indices
  7. SQL Query needed for fetch value from Two identical table but not fully identical table
  8. SQL select only rows with max value on a column [duplicate]
  9. How to create a MySQL hierarchical recursive query?
  10. Error related to only_full_group_by when executing a query in MySql
  11. How to reset AUTO_INCREMENT in MySQL
  12. How to declare a variable in MySQL?
  13. MySQL Query GROUP BY day / month / year
  14. MySQL Cannot Add Foreign Key Constraint
  15. Grouping into interval of 5 minutes within a time range
  16. SQL counting all rows instead of counting individual rows
  17. MySQL comparison with null value
  18. MySQL Like multiple values
  19. In MySQL, should I quote numbers or not?
  20. Matching all values in IN clause
  21. MySQL add days to a date
  22. Check for x consecutive days – given timestamps in database
  23. How to alter a column and change the default value?
  24. How to select one row randomly taking into account a weight?
  25. Remove special characters from a database field
  26. MySQL – Replace Character in Columns
  27. update a column by subtracting a value
  28. MySQL: Computed Column
  29. mySQL query to search all tables within a database for a string?
  30. How do I extract Month and Year in a MySQL date and compare them?

Leave a Comment