MySQL 5.7. Tutorial - Dutch PHP Conference 2015

MySQL 5.7
Dave Stokes
MySQL Community Manager
Oracle Corporation
David.Stokes@Oracle.com
@Stoker
Slideshare.net/davestokes
Opensourcedba.wordpress.com
https://joind.in/14195

2
Safe Harbor
The following is intended to outline our
general product direction. It is intended
for information purposes only, and may
not be incorporated into any contract. It is
not a commitment to deliver any material,
code, or functionality, and should not be
relied upon in making purchasing
decision. The development, release, and
timing of any features or functionality
described for Oracle’s products remains
at the sole discretion of Oracle. Take anything I say about
5.7 'with a grain of salt'
until it reaches GA status!

3
Happy Birthday MySQL!!!
● MySQL is 20
years old!
● InnoDB is 10!

4
Agenda
Some General Database Stuff
Some More Specific Database Stuff
MySQL 5.7 Release Candidate
Wrap-up, Q&A

5
General Database Stuff
● Roughly 2% of PHP Programmers have any training in
SQL

6
General Database Stuff
● Roughly 2% of PHP Programmers have any training in
SQL
● Very few of that 2% have a history of:
– Set theory
– Relational Database Design
– Relational Calculus
(Ahhhhh!
He said Calculus!!)

7
Structured Query Language
● SQL is a
– Declarative Language
● Tell the server WHAT you want
● Designed to store data efficiently
– Minimal duplications

8
Declarative Language
● SQL is for asking what you need
– Bad example #1 – Peperoni Pizza
– SELECT pie FROM oven WHERE topping = 'peperoni';

9
Declarative Language
● SQL is for asking what you need
– Bad example #1 – Peperoni Pizza
– SELECT pie FROM oven WHERE topping = 'peperoni';
● Many OO programers are doing the equivalent of starting with
growing grain, instantiate tomatoes, and re-discovering fire
– N+1 Problems
– Non Normalized Data
● Let database do the heavy lifting

10
Set Theory
● Noun
● The branch of mathematics that deals
with the formal properties of sets as units
(without regard to the nature of their
individual constituents) and the
expression of other branches of
mathematics in terms of sets.

11
A Intersection B
Think of data in SETS,
not records or objects

12
Hint: Download SQL Venn Diagram Image

13
What happens when you submit a query?
● Permissions checked
– Do you have proper access to
● Server
● Database
● Columns
● The query is checked for SYNTAX
● Query plan developed with lowest cost
● Query executed, results returned

14
Cost Based Optimizer
● The most expensive operation used to be reading
data off disk
– 100,000 times slower than a memory read!!
● The cost of fetching each item of data is estimated
– Past usage statistics used in estimates
– Each additional column selected is another
factorial of possible choices
● Does data need to be sorted, grouped, shoved
into a temporary table, cast, washed, folded,
dried, or other?!?

15
Query Cache Detour
● General idea:
– Cache the output of a query
– If query is run again, just return cached results!

16
Query Cache Detour Continued
● General idea:
– Cache the output of a query
– If query is run again, just return cached results!
● Problem:
– Query Cache is single threaded
● Think boarding an airplane, every goes through one door
– Don't use Query Cache, dedicate memory to
innodb_buffer_pool
– Turned off in 5.7

17
Cost Based Optimizer
● The most expensive operation used to be reading data off disk
– 100,000 times slower than a memory read
● The cost of fetching each item of data is estimated
– Past usage statistics used in estimates
● Changes in cost models
– Spinning, sold state, atomic writes, ….
– Working towards being able to set costs per device type
– Hardware vendors very creative
● Optimizer Trace (MySQL Workbench example)

18
Query Trace 1
● Simple Query:
Select City.Name,
Country.Name
FROM city
JOIN country ON (City.CountryCode = Country.Code)
ORDER BY Country.Name, City.Name

20
Query Trace 3
{
"query_block": {
"select_id": 1,
"cost_info": {
"query_cost": "5132.14"
},
"ordering_operation": {
"using_temporary_table": true,
"using_filesort": true,
"nested_loop": [
{
"table": {
"table_name": "country",
"access_type": "ALL",
"possible_keys": [
"PRIMARY"
],
"rows_examined_per_scan": 239,
"rows_produced_per_join": 239,
"filtered": "100.00",
"cost_info": {
"read_cost": "6.00",
"eval_cost": "47.80",
"prefix_cost": "53.80",
"data_read_per_join": "61K"
},
"used_columns": [
"Code", "Name"
}
},
{
"table": {
"table_name": "city",
"access_type": "ref",
"possible_keys": [
"CountryCode"
],
"key": "CountryCode",
"used_key_parts": [
"CountryCode"
],
"key_length": "3",
"ref": [
"world.country.Code"
],
"rows_examined_per_scan": 17,
"rows_produced_per_join": 4231,
"filtered": "100.00",
"cost_info": {
"read_cost": "4231.95",
"eval_cost": "846.39",
"prefix_cost": "5132.14",
"data_read_per_join": "727K"
},
"used_columns": [
"ID",
"Name",
"CountryCode"
]
}
}
]
}
}
}
This is probably
well beyond
what most
developers
would want to
look at for
improving a
query. But
DBAs would be
interested

21
Quick Question
●
Can you look at a query and tell if is is
good?
● SELECT rental_id
FROM rental
WHERE inventory_id = 10
AND customer_id = 3
AND return_date IS NULL;

23
Answer:
Impossible to tell given current data!

24
NULL? What is a NULL?
● NULL is used to denote 'no data'
● Gender Example
– M/F or NULL
● NULL fields are a PITA when indexed
● Math with NULL is usually equals NULL
– Some function depend on NULLs, RTFM
– Easy to shoot yourself in your own foot
● But NULLS can be extremely useful when used as originally
designed

25
Index
● MySQL mainly uses B-Tree indexes

26
Rough Indexing Rules
● Index columns on right side of WHERE clause
● Indexes require overhead so do not over index
– Find queries not using indexes
● Slow Query log with –log-queries-not-using-indexes
● Sys Schema
– Will also find unused indexes (do not use
immediately after a server restart)
● Index on Last_name, First_name, Middle_name will for for
– Last, First , Middle
– Last, First
– Last

28
MySQL 5.7 Release Candidate
● MySQL 5.7.7 – April 8th 2015
● New Features
● Patches
● Contributions
● Enhancements
● http://dev.mysql.com/doc/relnotes/mysql/5.7/en/ For the
details

29
JSON as a Data Type
mysql> CREATE TABLE employees (data JSON);
Query OK, 0 rows affected (0,01 sec)
mysql> INSERT INTO employees VALUES ('{"id": 1, "name": "Jane"}');
Query OK, 1 row affected (0,00 sec)
mysql> INSERT INTO employees VALUES ('{"id": 2, "name": "Joe"}');
Query OK, 1 row affected (0,00 sec)
mysql> select * from employees;
+---------------------------+
| data |
+---------------------------+
| {"id": 1, "name": "Jane"} |
| {"id": 2, "name": "Joe"} |
+---------------------------+
2 rows in set (0,00 sec)

30
JSON Data Type
● Document Validation
– Only valid JSON documents can be stored in a JSON column, so
you get automatic validation of your data. If you try to store an
invalid JSON document in a JSON column, you will get an error
● Efficient Access
– JSON document in a JSON column it is stored in an optimized
binary format that allows for quicker access to object members and
array elements.
– The binary format of a JSON column contains a preamble with a
lookup table. The lookup table has pointers to every key/value pair
in the JSON document, sorted on the key. The JSN_EXTRACT
function to perform a binary search for the ‘name’ key in the table
and read the corresponding value directly, without having to parse
the ‘id’ key/value pair that precedes it within the JSON document.

31
JSON Data Type Functions
● Manipulating JSON documents:
– jsn_array()
– jsn_object()
– jsn_insert()
– jsn_remove()
– jsn_set()
– jsn_replace()
– jsn_append()
– jsn_merge()
– jsn_extract()
● JSON Query:
– JSN_SEARCH()
– JSN_CONTAINS()
– JSN_CONTAINS_PATH()
– JSN_VALID()
– JSN_TYPE()
– JSN_KEYS()
– JSN_LENGTH()
– JSN_DEPTH()
– JSN_UNQUOTE()
– JSN_QUOTE()

32
Quick Example
mysql> desc colors;
● +--------------+----------+------+-----+---------+-------------------+
● | Field | Type | Null | Key | Default | Extra |
● +--------------+----------+------+-----+---------+-------------------+
● | popular_name | char(10) | YES | | NULL | |
● | hue | json | YES | | NULL | |
● +--------------+----------+------+-----+---------+-------------------+
● 2 rows in set (0.00 sec)
INSERT INTO `colors` VALUES ('red','{"value": "f00"}'),
('green','{"value": "0f0"}'),('blue','{"value": "00f"}'),
('cyan','{"value": "0ff"}'),('magenta','{"value": "f0f"}'),
('yellow','{"value": "ff0"}'),('black','{"value": "000"}');

33
Using jsn_extract
mysql> select jsn_extract(hue, '$.value') from colors where
jsn_extract(hue, '$.value')="f0f";
+-----------------------------+
| jsn_extract(hue, '$.value') |
+-----------------------------+
| "f0f" |
+-----------------------------+
1 row in set (0.00 sec)

34
Another JSON Trick
create table users( id int, name varchar(50), old int );
Insert into users values( 1, ‘kerem’, 30 ), ( 2, ‘john’, 35 );
select jsn_array( id, name, old ) from users;
select jsn_object
(
‘u_id’, id,
‘u_name’, name,
‘u_old’, old
) from users;
Note: JSN_ARRAY and
JSN_OBJECT will be
renamed JSON_ARRAY
and JSON_OBJECT for the
second Release Candidate
of MySQL 5.7

35
JSON via HTTP Plug-in
● MySQL has a new plugin that lets HTTP clients and
JavaScript users connect to MySQL using HTTP.
– The development preview brings three APIs:
● Key-document for nested JSON documents
● CRUD for JSON mapped SQL tables
● SQL with JSON replies.

36
Security
● Secure by default
– You will get a root password
– Bye-bye anonymous account
● User='' and password=''
– No test database
● Password rotation/ expiration at your control
● Lock accounts – CREATE/ALTER USER
● Proxy logins
● The C client library now attempts to establish an SSL connection by
default whenever the server is enabled to support SSL

37
A quick diversion into MySQL Logins
● MySQL Login Authentication is promiscuous
– First checks new connection to see if host is okay
– They starts checking user / password
● Takes first match, not best match!!!
● Boss @ 10.10.x.x may not be the same as
Boss @ %

38
A quick diversion into MySQL Logins
● MySQL Login Authentication is promiscuous
– First checks new connection to see if host is okay
– They starts checking user / password
● Takes first match, not best match!!!
● Boss @ 10.10.x.x may not be the same as
Boss @ %
– Most likely will have different permissions for each
account
– Self audit to double check

39
Quick Quiz
IP User Password/A
uthentication
String
10.10.*
% Boss hshwgwgs
10.10.10.* Boss KewWEds
192.168.10.* Joe
% Joe YwSWEDS
● Who can login from the
10.10 network?
● Where can Boss login
from?
● Where does Joe need a
password?
● What happens if Boss is
put on a new vlan of
10.10.11?

40
Performance Schema & SYS Schema
● You asked for SYS Schema included by default for 5.7
● Better instrumentation
– Can be turned on/off, instruments on/off
– Cost 2.5-3% Overhead
– Similar to Oracle V$ variables
– Use MySQL Workbench for dashboard

41
SYS Schema
● The Performance Schema feature is an amazing resource for runtime
instrumentation within MySQL. There is a lot of information is
available, but sometimes it is hard to distill. The MySQL SYS schema
builds on both the performance_schema and
INFORMATION_SCHEMA databases, exposing a set of views,
functions, and procedures modeled directly for many day-to-day
administrator tasks, such as:
– Analyzing user load
– Analyzing database object load
– Analyzing resource utilization
– Digging into poorly performing SQL
– Deeply analyzing what connections are doing

42
host_summary_by_file_io
● Summarizes file IO totals per host.
● mysql> select * from host_summary_by_file_io;
+------------+-------+------------+
| host | ios | io_latency |
+------------+-------+------------+
| hal1 | 26457 | 21.58 s |
| hal2 | 1189 | 394.21 ms |
+------------+-------+------------+

43
Waiting for a lock
mysql> SELECT * FROM innodb_lock_waitsG
*************************** 1. row ***************************
wait_started: 2014-11-11 13:39:20
wait_age: 00:00:07
locked_table: `db1`.`t1`
locked_index: PRIMARY
locked_type: RECORD
waiting_trx_id: 867158
waiting_trx_started: 2014-11-11 13:39:15
waiting_trx_age: 00:00:12
waiting_trx_rows_locked: 0
waiting_trx_rows_modified: 0
waiting_pid: 3
waiting_query: UPDATE t1 SET val = val + 1 WHERE id = 2
waiting_lock_id: 867158:2363:3:3
waiting_lock_mode: X
blocking_trx_id: 867157
blocking_pid: 4
blocking_query: UPDATE t1 SET val = val + 1 + SLEEP(10) WHERE id = 2
blocking_lock_id: 867157:2363:3:3
blocking_lock_mode: X
blocking_trx_started: 2014-11-11 13:39:11
blocking_trx_age: 00:00:16
blocking_trx_rows_locked: 1
blocking_trx_rows_modified: 1

44
Memory
mysql> select * from memory_global_total;
+-----------------+
| total_allocated |
+-----------------+
| 458.44 MiB |
+-----------------+

45
Full Table Scans
mysql> select * from schema_tables_with_full_table_scans limit 5;
+--------------------+--------------------------------+-------------------+-----------+
| object_schema | object_name | rows_full_scanned | latency |
+--------------------+--------------------------------+-------------------+-----------+
| mem30__instruments | fsstatistics | 10207042 | 13.10 s |
| mem30__instruments | preparedstatementapidata | 436428 | 973.27
ms |
| mem30__instruments | mysqlprocessactivity | 411702| 282.07 ms
|
| mem30__instruments | querycachequeriesincachedata | 374011 |
767.15 ms |
| mem30__instruments | rowaccessesdata | 322321 | 1.55 s |
+--------------------+--------------------------------+-------------------+-----------

46
Unused Indexes
mysql> select * from schema_tables_with_full_table_scans limit 5;
+--------------------+--------------------------------+-------------------+-----------+
| object_schema | object_name | rows_full_scanned | latency |
+--------------------+--------------------------------+-------------------+-----------+
| mem30__instruments | fsstatistics | 10207042 | 13.10 s |
| mem30__instruments | preparedstatementapidata | 436428 | 973.27
ms |
| mem30__instruments | mysqlprocessactivity | 411702 | 282.07 ms |
| mem30__instruments | querycachequeriesincachedata | 374011 | 767.15
ms |
| mem30__instruments | rowaccessesdata | 322321 | 1.55 s |
+--------------------+--------------------------------+-------------------+-----------
Do not run after a restart!!!!!!!!

47
Mimic Enterprise Monitor Query Analysis
mysql> select * from statement_analysis limit 1G
*************************** 1. row ***************************
query: SELECT * FROM `schema_object_o ... MA` , `information_schema` ...
db: sys
full_scan: *
exec_count: 2
err_count: 0
warn_count: 0
total_latency: 16.75 s
max_latency: 16.57 s
avg_latency: 8.38 s
lock_latency: 16.69 s
rows_sent: 84
rows_sent_avg: 42
rows_examined: 20012
rows_examined_avg: 10006
rows_affected: 0
rows_affected_avg: 0
tmp_tables: 378
tmp_disk_tables: 66
rows_sorted: 168
sort_merge_passes: 0
digest: 54f9bd520f0bbf15db0c2ed93386bec9
first_seen: 2014-03-07 13:13:41
last_seen: 2014-03-07 13:13:48

48
Who is making errors
mysql> select * from statements_with_errors_or_warnings
LIMIT 1G
*************************** 1. row ***************************
query: CREATE OR REPLACE ALGORITHM = ...
_delete` AS `rows_deleted` ...
db: sys
exec_count: 2
errors: 1
error_pct: 50.0000
warnings: 0
warning_pct: 0.0000
first_seen: 2014-03-07 12:56:54
last_seen: 2014-03-07 13:01:01
digest: 943a788859e623d5f7798ba0ae0fd8a9

49
Queries in top 95 percentile run time
mysql> select * from statements_with_runtimes_in_95th_percentileG
*************************** 1. row ***************************
query: SELECT * FROM `schema_object_o ... MA` ,
`information_schema` ...
db: sys
full_scan: *
exec_count: 2
err_count: 0
warn_count: 0
total_latency: 16.75 s
max_latency: 16.57 s
avg_latency: 8.38 s
rows_sent: 84
rows_sent_avg: 42
rows_examined: 20012
rows_examined_avg: 10006
first_seen: 2014-03-07 13:13:41
last_seen: 2014-03-07 13:13:48
digest: 54f9bd520f0bbf15db0c2ed93386bec9

50
User Summary
************************** 1. row ***************************
user: root
statements: 4981
statement_latency: 26.54 s
statement_avg_latency: 5.33 ms
table_scans: 74
file_ios: 7792
file_io_latency: 40.08 s
current_connections: 1
total_connections: 2
unique_hosts: 1
current_memory: 3.57 MiB
total_memory_allocated: 83.37 MiB
*************************** 2. row ***************************
user: background
statements: 0
statement_latency: 0 ps
statement_avg_latency: 0 ps
table_scans: 0
file_ios: 1618
file_io_latency: 4.78 s
current_connections: 21
total_connections: 23
unique_hosts: 0
current_memory: 165.94 MiB
total_memory_allocated: 197.29 MiB

51
Who is using up the io?
mysql> select * from user_summary_by_file_io;
+------------+-------+------------+
| user | ios | io_latency |
+------------+-------+------------+
| root | 26457 | 21.58 s |
| background | 1189 | 394.21 ms |
+------------+-------+------------+

52
Database Synonym
mysql> CALL sys.create_synonym_db('performance_schema',
'ps');
● Great for shortening long database names

53
Spatial Support
● Working closely with Boost.Geometry
● Superset of OpenGIS
● Test with Sakila test database with GIS info included

54
Replication
● Multi-threaded – Now parallel withing a database
● Multi-source replication
● CHANGE REPLICATION FILTER – Without restarting
● CHANGE MASTER – Without restarting
● SHOW SLAVE STAUS – Non blocking
● Performance Schema – Replication details

55
Generated columns
● two kinds of Generated Columns:
– virtual (default)
● the column will be calculated on the fly when a
record is read from a table
– stored
● Stored means that the column will be calculated
when a new record is written in the table, and after
that it will be treated as a regular field.

56
Generated columns
● Two kinds of Generated Columns:
– virtual (default)
● the column will be calculated on the fly when a
record is read from a table
– stored
● Stored means that the column will be calculated
when a new record is written in the table, and after
that it will be treated as a regular field.
● Use with JSON data type for indexes

57
JSON Index Example
Using generated columns to index non-
relational JSON data
● ALTER TABLE colors ADD value_ext
char(10) GENERATED ALWAYS AS
(jsn_extract(hue, '$.value')) VIRTUAL;
● CRATE INDEX value_ext_index ON
colors(value_ext);

58
Better upgrade (and down grade)
● Yes, we know upgrading can be painful!
– Upgrading (and down grading) now part of our daily QA
Testing.

59
SQL Mode
● 5.7 default is STRICT
● Strict mode controls how MySQL handles invalid or
missing values in data-change statements such as
INSERT or UPDATE.
A value can be invalid for several reasons. For example, it
might have the wrong data type for the column, or it might
be out of range. A value is missing when a new row to be
inserted does not contain a value for a non-NULL column
that has no explicit DEFAULT clause in its definition. (For a
NULL column, NULL is inserted if the value is missing.)
● Breaks Wordpress

60
Better connection handling
● In some application scenarios (e.g. PHP applications) client
connections have very short life spans, perhaps only
executing a single query. This means that the time spent
processing connects and disconnects can have a large impact
on the overall performance.
In 5.7 we have offloaded thread initialization and network
initialization to a worker thread (WL#6606) and more than
doubled MySQL’s ability to do high frequency
connect/disconnect cycles, from 26K to 56K
connect/disconnect cycles per second. See also Jon Olav
Hauglid’s article “Improving connect/disconnect performance“.

61
Bulk Data Load
● Bulk Load for Create Index (WL#7277). This work
implements bulk sorted index builds, thus making CREATE
INDEX operations much faster.
Prior to this work InnoDB looped through the base table
and created one index record at a time for each record in
the base table. After this work InnoDB reads many records
from the base table, sorts the records using the index key,
and then creates a chunked set of index records in one
single bulk operation.

62
InnoDB Full Text
● Better than MyISAM version
● CJK (Chinese, Japanese, Korean) support
– no fixed separators for individual words
– each word can be compromised of multiple characters
● MeCab – Morphological parser
– full-text parser plugin for Japanese
– Character sets: eucjpms (ujis), cp932 (sjis), and utf8
(utf8mb4)
● Also MySQL 5.7 now supports the GB18030 Chinese National
Standard Character Set

63
Set levels of error logging
● --log_error_verbosity=3
● Pick you level
– Errors only
– Errors and Warnings
– Errors, Warnings, and Notes
● Set on the fly!

64
Explain for running queries
● EXPLAIN [options] FOR CONNECTION connection_id;

65
Server-side statement timeouts
● Global, session or for individual SELECT statements
● SELECT MAX_STATEMENT_TIME = 120 * FROM
Customer;
Put this in your boss's ~/.my.cnf

66
TRIGGERS
● Triggers can now be stacked
● mysql> delimiter //
mysql> CREATE TRIGGER upd_check BEFORE UPDATE ON account
-> FOR EACH ROW
-> BEGIN
-> IF NEW.amount < 0 THEN
-> SET NEW.amount = 0;
-> ELSEIF NEW.amount > 100 THEN
-> SET NEW.amount = 100;
-> END IF;
-> END;//
mysql> delimiter ;

67
InnoDB
● INNODB_BUFFER_POOL_SIZE – Dynamic
● Transportable Table Spaces
● INNODB_BUFFER_POOL_DUMP_PCT – save
percentage of buffer pool recently used pages to save

68
Deprecated
● YEAR(2) removed – must convert to YEAR(4)
● IGNORE clause for ALTER TABLE
● INSERT DELAYED ignored
● SHOW ENGINE INNODB MUTEX
– Use Performance Schema

69
Upgrade 5.6 to 5.7
● It is good practice to back up your data before installing any
new version of software. Although MySQL works very hard to
ensure a high level of quality, protect your data by making a
backup.
● To upgrade from 5.6 to 5.7, MySQL recommends you perform
an in-place binary upgrade using this procedure:
– Stop the old (MySQL 5.6) server
– Upgrade the MySQL binaries or packages in place (replace
the 5.6 binaries with those from 5.7)
– Start the MySQL 5.7 server using the existing data
directory
– Run mysql_upgrade to upgrade the system tables and
initialize everything for 5.7 use

70
MySQL Fabric
● If you can set up MySQL
Replication, you can set up
MySQL Fabric
● Series of scripts to set up
server farms for
– High Availability
– Sharding
● The Connector has the
'smarts' about the farms, no
need to change application to
re-shard or when master fails

71
MySQL Utilities
● 28 Scripts written in Python
– Automatic server fail over
– Grep for process and kill it
– Grep for column names
– Check replication
– Copy databases
– Copy grants/permissions
– Diff
– Disk usage
– Clone Servers

72
MySQL Utilities Cont
● Audit Log admin, grep
● Binlog relocate, purge,
rotate
● Database copy, export,
import, diff
● Disk usage
● Replication failover
● Grants copy, check, user
clone
● Redundant indexes
● Replication check, sync,
server clone, admin, setup,
skip transactions
● Grep processes (and kill
'em), table

73
Mysqldbcopy example
shell> mysqldbcopy
--source=root:pass@localhost:3310:/test123/mysql.sock
--destination=root:pass@localhost:3310:/test123/mysql.sock
util_test:util_test_copy
# Source on localhost: ... connected.
# Destination on localhost: ... connected.
# Copying database util_test renamed as util_test_copy
# Copying TABLE util_test.t1
# Copying table data.
# Copying VIEW util_test.v1
# Copying TRIGGER util_test.trg
# Copying PROCEDURE util_test.p1
# Copying FUNCTION util_test.f1
# Copying EVENT util_test.e1
# Copying GRANTS from util_test
#...done.

74
Kill processes sleeping over 1 hour
shell> mysqlprocgrep
--server=root@localhost
--match-command=sleep --age=1h
--kill-connection

76
Q&A
David.Stokes@Oracle.com @Stoker
Slideshare.net/davestokes
OpenSourceDBA@Wordpress.Com
https://joind.in/14195

MySQL 5.7. Tutorial - Dutch PHP Conference 2015

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