This document summarizes Eli Aschkenasy's MySQL performance talk on database engine selection, server updates, data types, counter tables, indexing, and query optimization. The talk discusses choosing between the MyISAM and InnoDB database engines, keeping servers updated, using smaller and optimized data types like TINYINT and VARCHAR, implementing counter tables to track row additions, using indexes for performance and selectivity, and optimizing queries through limiting result sets, avoiding unnecessary data retrieval, and using indexes to reduce workload. The overall message is that newer software, optimized structures, and efficient queries can significantly improve database performance.

1. MySQL Performance Talk
May 29 2012
Eli Aschkenasy
@EliAschkenasy

2. Check list
 DB engine selection

3. Engines:
MyISAM vs. INNODB

4. Source: Oracle Jan, 2011

5. Source: Oracle Jan, 2011

6. Source: Oracle Jan, 2011

7. Source: Oracle Jan, 2011

8. Source: Google (google fix) 1Q, 2010

9. Check list
 DB engine selection
 Server update

10. Source: Giuseppe Maxia - MySQL Community Team Lead 1Q, 2010

11. Source: Giuseppe Maxia - MySQL Community Team Lead 1Q, 2010

12. Source: Giuseppe Maxia - MySQL Community Team Lead 1Q, 2010

13. Bottom line:
Newer ISbetter

14. Check list
 DB engine selection
 Server update
 Data types

15. Data Types Rules:
 Smaller is better (usually)
 Avoid NULL if possible (index/comparison)
 Don’t forget about TINYINT and (UN)SIGNED
 ALL INT calculations create 64bit BIGINT (storage is the only difference)
 Width identifier is meaningless – INT(1) occupies the same space as INT(20)
 VARCHAR vs. CHAR – fixed allocation of space (CHAR)
 Downside of VARCHAR is that the row might grow.
 BLOB and TEXT are identical other than collation and character set information
 ENUM

16. Data Types Rules:

17. Data Types Rules:
 Smaller is better (usually)
 Avoid NULL if possible (index/comparison)
 Don’t forget about TINYINT and (UN)SIGNED
 ALL INT calculations create 64bit BIGINT (storage is the only difference)
 Width identifier is meaningless – INT(1) occupies the same space as INT(20)
 VARCHAR vs. CHAR – fixed allocation of space (CHAR)
 Downside of VARCHAR is that the row might grow.
 BLOB and TEXT are identical other than collation and character set information
 ENUM (Don’t use)
 DATE vs. DATETIME

18. Check list
 DB engine selection
 Server update
 Data types
 Counter tables

19. mysql > SELECT COUNT(*) FROM asset_table;
mysql > CREATE TABLE asset_counter (
cnt INT UNSIGNED NOT NULL
) ENGINE=InnoDB;
On addition:
UPDATE asset_counter SET cnt = cnt+1;
mysql > CREATE TABLE asset_counter (
slot TINYINT UNSIGNED NOT NULL PRIMARY KEY,
cnt INT UNSIGNED NOT NULL
) ENGINE=InnoDB;
Pre-populate 100 rows (slot will be 1 – 100)
On addition:
UPDATE asset_counter SET cnt = cnt+1 WHERE slot = RAND() * 100;

20. Check list
 DB engine selection
 Server update
 Data types
 Counter tables
 Indexing (even for ORMs)

21. Indexing 1: hash – (for lookup tables)
InnoDB creates this automatically for frequently accessed index values.

22. Indexing 2: selectivity – (multi column indexes)

23. Check list
 DB engine selection
 Server update
 Data types
 Counter tables
 Indexing (even for ORMs)
 Query optimization

24. Query optimization:
Optimize data AMOUNT
Use Limit in your Query (instead of the application code)
Deadly * - Do you really need ALL data from a row ?!?
Double data – same resource in multiple queries
Reduce DB workload
Use Indexes!
Use a covering index (remember selectivity?)
Complex query vs. Many simple queries

25. Query optimization:

26. Query optimization:

27. Query optimization:

28. Bottom (bottom) line:
Always check real data!