The document provides a high-level overview of MySQL in 3 sentences: MySQL is a popular open source database management system. It allows users to manage and query relational databases and is commonly used for both small and large-scale projects. MySQL works across many operating systems and provides transactional support and flexibility through different storage engines.

1. MySQL Overview
a quick look at the general aspects of the most
popular open source database
Marco Tusa
MySQL Team Leader
16 September 2011

2. Why Companies Trust Pythian
• Recognized Leader:
• Global industry-leader in remote database administration services and consulting for Oracle,
Oracle Applications, MySQL and SQL Server
• Work with over 150 multinational companies such as Forbes.com, Fox Interactive media, and
MDS Inc. to help manage their complex IT deployments
• Expertise:
• One of the world’s largest concentrations of dedicated, full-time DBA expertise.
• Global Reach & Scalability:
• 24/7/365 global remote support for DBA and consulting, systems administration, special
projects or emergency response
22 © 2010/2011 Pythian

3. Why Companies Trust Pythian
• Recognized Leader:
• Global industry-leader in remote database administration services
and consulting for Oracle, Oracle Applications, MySQL and SQL Server
• Work with over 150 multinational companies such as Toyota, Fox
Interactive media, and MDS Inc. to help manage their complex IT
deployments
• Expertise:
• One of the world’s largest concentrations of dedicated, full-time DBA
expertise.
• Global Reach & Scalability:
• 24/7/365 global remote support for DBA and consulting, systems
administration, special projects or emergency response
32 © 2010/2011 Pythian

4. Who I am
• Currently: Team Lead at The Pythian Group for MySQL database
support
• Manager Professional Service South EMEA at MySQL/SUN/Oracle
• In MySQL before the SUN gets on us
• Leadingthe team responsible for Oracle & MySQL DBs service in
support to technical systems, at Food and Agriculture Organization
of United Nations (FAO of UN)
• Leading developer & system administrator teams in FAO managing
the Intranet/Internet infrastructure.
• Working(a lot) in developing countries like (Ethiopia, Senegal,
Ghana, Egypt …)
• My Profile http://it.linkedin.com/in/marcotusa
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5. What is MySQL?
• MySQL is a database management system
• MySQL is a relational database management system
• MySQL software is Open Source.
• MySQL Server works in client/server or embedded systems.
• The official way to pronounce “MySQL” is “My Ess Que
Ell” (not “my sequel”)
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6. Who is using MySQL
List of customer from MySQL official presentation
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7. Main insight on MySQL 1/2
• Written in C and C++.
• Works on many different platforms:
• FreeBSD 5.x.
• HP-UX 11.x.
• Linux.
• Mac OS X.
• Solaris 2.8 on SPARC and x86
• Windows XP, Windows Vista, Windows Server 2003, and
Windows Server 2008.
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8. Main insight on MySQL 2/2
• Uses multi-layered server design with independent
modules.
• Designed to be fully multi-threaded using kernel threads,
to easily use multiple CPUs if they are available.
• Provides transactional and non-transactional storage
engines.
• Designed to make it relatively easy to add other storage
engines. This is useful if you want to provide an SQL
interface for an in-house database.
• Uses a very fast thread-based memory allocation system.
• Full Localization support
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9. What Standards MySQL Follows?
• Supports the full ANSI/ISO SQL standard, but with some
flexibility (SQL-92=1992 Release; SQL:1999=1999 Release; SQL:2003=2003
Release; SQL:2008= 2008 Release).
http://www.iso.org/iso/home.htm
• ODBC levels 0 to 3.51.
• MySQL can adapt its behavior using SQL Modes like:
• ANSI (SET GLOBAL sql_mode='ANSI';)
• Oracle
• Custom …
• MySQL DATA is structured on the file system by directory
and subdirectory (symbolic links widely used)
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10. Installing MySQL in 4 easy steps
Installing MySQL is a simple operation:
1. ownload software from site like (http://dev.mysql.com/get/
D
Downloads/MySQL-5.5/mysql-5.5.15-linux2.6-x86_64.tar.gz/from/http://
mirror.csclub.uwaterloo.ca/mysql/)
2. xpand it in /usr/local/mysql (and set all grants for mysql user)
E
3. opy one of the pre-configured my.cnf (from support-files
C
directory) to /etc/my.cnf; copy from same source
mysql.server file to /etc/init.d/mysql
4. tart mysql /etc/init.d/mysql start
S
You can have MySQL running in 30 minutes.
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11. MySQL Architecture 1/2
MySQL is composed of two main layers
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12. MySQL Architecture 2/2
• MySQL Layer (Parser; Optimizer; Query cache; threads
handling )
• Storage engines:
• MyISAM ( no ACID)
• Innodb (ACID)
• Cluster (ACID)
• Archive (only archive and append)
• Memory (Main engine for in memory operations)
• Blackhole (it is exactly what the name indicate)
• .. many others
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13. MySQL Storage engine more details 1/2
They have different advantages / trade-offs - know when to
use them.
1. yISAM
M
• No transaction handling; no isolation level; no data buffered (only index); full Table
lock; no foreign key;
• Fully file base; minimal overhead in write; very fast in reading; Btree index; Full text
search; Geospatial support; 256TB Storage limit;
2. nnoDB
I
• No full text (5.6 will); no Geospatial support; no cluster support; 64TB Storage limit;
• Full ACID; possible to modify the Isolation level; data is buffered; Write lock by ROW;
Foreign-key support; automatic recovery from redo log in case of crash; Btree index;
Clustered table; different file format (internal); data compression.
3. emory
M
• No transaction; no version control; no Geospatial support; no foreign-key; full Table
lock;
• Data cached in memory; Btree index; Hash index; Storage limit is the available RAM.
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14. MySQL Storage engine more details 2/2
1. MySQL Cluster
• No geospatial support; no foreign-key; no “Temporary” tables; partition only by
[LINEAR] KEY; only the READ COMMITTED isolation level is supported; no partial roll-
back (full or nothing); a Select on Blob or Text fields will create a READ LOCK on the
table to guarantee consistency.
• Fully ACID; share nothing architecture; single point of failure; write scale by node-
group; thread requests parallelization; and a lot more …
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15. MySQL Logs 1/2
What they are and how MySQL uses them.
• General Log
• each SQL statement received from clients; connection/disconnection as well
• Write intensive to be used ONLY for checking issues
• Binary log
• Contains the statements “events” that modify data structure and datasets
• Point in time recovery; Replication; Backup; can be (statement/mixed/row)
• Relay log
• Is the local copy of the Slave; contains the same information of the Binlogs
• Slow log
• The Error Log
• Self explanatory in the latest MySQL can write to syslog
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16. MySQL Logs 2/2
What they are and how MySQL uses them.
• Slow log
• Information related to SLOW QUERY
• Could be write intensive; long time and no index usage configurable
• Crucial for SQL review
• The Error Log
• If not specify --log-error errors are written to stderr
• Warnings are written as well (log_warnings) to disable
• From MySQL 5.1 can also write to syslog
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17. MySQL Replication
Replication topology, and when to use what.
• Master -> Slave
• Master <> Master
• Master -> Multi slave
• MySQL replication pro and cons
• Single thread
• Parallel replication
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• Asynchronous
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18. Scaling with MySQL
Replication.
• caling for reads
S
• Add slave(s) but … keep in mind
PT = (ND + QT) * NL
PT = Propagation Time ND = Network time delay QT = Query Execution Time NL = Number of Level
• caling for writes
S
• Sharding or MySQL Cluster
• caling out vs. scaling up
S
• Partition
• Spread the load in smaller chunk
• sing the right approach
U
• Database dimension
• Activity (r/w)
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19. Partitioning 1/2
Use Partition to organize data
Max number of partition per table !1024!
Types of partitioning
• ANGE
R
• Numeric range like (store Id; Year) less then “value”
• IST
L
• Declared list of value (matching one in the list)
• OLUMNS
C
• RANGE: List of a single column value or more (partition definition value list)
evaluation left->right
• LIST: Declared list of value coming from one or more columns
• No DECIMAL, FLOAT,TIMESTAMP,TEXT,BLOB
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20. Partitioning 2/2
Types of partitioning (cont.)
• ASH
H
• Calculate an hash value on the given value (also expression)
then equally distribute the data
• EY
K
• Calculate an hash value on Primary/Unique
• ubpartitioning
S
• Works for LIST and RANGE Partitioned tables
• Subpartition only by HASH or KEY
Partition cannot be done on table with: Full Text index ; Spatial
columns
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21. MySQL programming 2/2
A few point about performance
• Not as good you would expect
• Optimize IF
• Recursive VS not recursive
calculating Fibonacci numbers
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22. MySQL programming
Using stored procedure (code for performance on prime
numbers) CREATE PROCEDURE sp_nprimes(p_num int)
PROCEDURE N_PRIMES
( p_num NUMBER) BEGIN
IS DECLARE i INT;
i INT; DECLARE j INT;
j INT; DECLARE nprimes INT;
nprimes INT; DECLARE isprime INT;
isprime INT;
BEGIN SET i=2;
i:=2; SET nprimes=0;
nprimes:=0;
<<main_loop>> main_loop:
WHILE (i<p_num) LOOP WHILE (i<p_num) do
isprime:=1; SET isprime=1;
j:=2; SET j=2;
<<divisor_loop>> divisor_loop:
WHILE (j<i) LOOP WHILE (j<i) DO
IF (MOD(i,j)=0) THEN IF (MOD(i,j)=0) THEN
isprime:=0; SET isprime=0;
EXIT divisor_loop; LEAVE divisor_loop;
END IF; END IF;
j:=j+1; SET j=j+1;
END LOOP ; END WHILE ;
IF (isprime=1) THEN IF (isprime=1) THEN
nprimes:=nprimes+1; SET nprimes=nprimes+1;
END IF; END IF;
i:=i+1; SET i=i+1;
END LOOP; END WHILE;
dbms_output.put_line(nprimes||' prime numbers SELECT CONCAT(nprimes,' prime numbers less
less than '||p_num); than ',p_num);
END; END;
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23. MySQL programming
Using Store procedure (code for Fibonacci test)
Recursive
Not Recursive
CREATE PROCEDURE nonrec_fib(n INT,OUT out_fib INT)
CREATE PROCEDURE rec_fib(n INT,OUT out_fib BEGIN
INT) DECLARE m INT default 0;
BEGIN DECLARE k INT DEFAULT 1;
DECLARE n_1 INT; DECLARE i INT;
DECLARE n_2 INT; DECLARE tmp INT;
IF (n=0) THEN SET m=0;
SET out_fib=0; SET k=1;
ELSEIF (n=1) then SET i=1;
SET out_fib=1;
ELSE WHILE (i<=n) DO
CALL rec_fib(n-1,n_1); SET tmp=m+k;
CALL rec_fib(n-2,n_2); SET m=k;
SET out_fib=(n_1 + n_2); SET k=tmp;
END IF; SET i=i+1;
END END WHILE;
SET out_fib=m;
END
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24. MySQL programming 1/2
• Using Store procedure
• Programming is real at a basic level; no packages etc…
• Triggers and function could leads to unexpected results by Storage
engine
• Real status about store procedure
• Triggers; Functions; Store procedure
• Using SELECT INTO is fine for single-row queries; CURSORS; Unbound result set (return
result set to calling application); Non SELECT actions (update, insert, delete); Internal
CALL to other Store Procedure; few info about performance
• Error handling available from 5.5 onwards with SIGNAL and RESIGNAL
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25. MySQL HA solution
How many nines do you need?
9 0. 0 0 0 % (36 days) MySQL Replication
9 9. 0 0 0 % (8 hours) Linux Heartbeat with DRBD
9 9. 0 0 0 % (8 hours) Linux Heartbeat with Shared Storage
(Active/Passive)
9 9. 0 0 0 % (8 hours) Linux Heartbeat with Shared Storage
(Active/Active)
9 9. 9 0 0 % (52 minutes) Linux Heartbeat with DRBD and Replication
9 9. 9 0 0 % (52 minutes) Linux Heartbeat with Shared Storage and
Replication
9 9. 9 9 9 % (5 minutes) MySQL Cluster
9 9. 9 9 9 % (5 minutes) MySQL Cluster & Replication
9 9. 9 9 9 % (5 minutes) MySQL Cluster Carrier Grade Edition
[Time is possible outage per year]
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26. MySQL Backup
• Logical MySQL Backup
• mysqldump
• export
• Physical MySQL backup
• LVM Snapshot
• ZFS snapshot
• File copy
• Hot Backup (xtrabackup)
• Incremental backup
– Xtrabackup
– binlogs
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27. Managing MySQL
MySQL tools
• lient application
C
• Non GUI
• mysql — The MySQL Command-Line Tool
• mysqladmin — Client for Administering a MySQL Server
• mysqlcheck — A Table Maintenance Program
• mysqldump — A Database Backup Program
• mysqlimport — A Data Import Program
• mysqlshow — Display Database, Table, and Column Information
• UI
G
• Workbench; Navicat; SQLyog … Google
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28. Managing MySQL
Administration tools
• Non GUI
• innochecksum — Offline InnoDB File Checksum Utility
• myisam_ftdump — Display Full-Text Index information
• myisamchk — MyISAM Table-Maintenance Utility
• myisampack — Generate Compressed, Read-Only MyISAM Tables
• mysqlaccess — Client for Checking Access Privileges
• mysqlbinlog — Utility for Processing Binary Log Files
• mysqldumpslow — Summarize Slow Query Log Files
• mysqlhotcopy — A Database Backup Program (Archive MyISAM)
• perror — Explain Error Codes
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29. Monitoring MySQL Status
• MySQL enterprise monitor
• Historical monitor
• Cacti
• MONyog
• Live monitoring
• What we do at Pythian
 Avail software for monitoring of paging/alerts and daily
pro-active checks
• Scripts
• Nagios plugin
• Issue is: define the correct parameters to monitor
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30. Use the right tool for the right use
What MySQL is good for
• TLP
O
• mall/mid size datasets (per instance) say less then 10Tb
S
• pplications using many simultaneous connections
A
What is better to avoid
• ata warehouse
D
• pplications requiring heavy usage of Stored Procedure
A
• pplications requiring Hierarchical query (connect by prior etc.)
A
• atasets that could not scale by SHARD
D
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31. Q & A
Thank you!
tusa@pythian.com
http://www.pythian.com/
http://www.pythian.com/news/
Interested in joining our elite team of trusted database expert?
Pythian is hiring.
More details at: http://www.pythian.com/about/careers/job-
listings/
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