Presentation for MySQL UC 2006 on MySQL for the Oracle DBA

1. MySQL for Oracle DBAs
Mark Leith
Support Engineer, MySQL AB
mleith@mysql.com
1

2. Introduction
9 years database experience, starting with
Oracle
5 years MySQL experience
Extensive experience with database tools
Working within the MySQL Support Group,
for the Americas region
2

3. Agenda
MySQL Architecture
Backup and Recovery
Managing space and tables
Managing Memory
Tracing Sessions / Auditing
Monitoring Tools and Tips
Connecting MySQL to Oracle
Questions
3

4. Architecture
Product Architecture
Internal Memory Structures
Filesystem Layout
Binaries
Database / Table Datafiles
Log Files
Permissions / Ownership
4

5. Product Architecture
5

6. Internal Memory Structures
6

7. Filesystem Layout - Binaries
Windows default: C:Program FilesMySQLMySQL Server x.xbin
Tarball default: /usr/local/mysql/bin
RPM default: /usr/lib/mysql, /usr/bin & /usr/sbin (depending on RPM)
MySQL Server executables
mysqld, mysqld-debug, mysqld-max
MySQL Client Utilities
mysql, mysqldump, mysqlcheck, mysqlbinlog ..
Upgrade and Security scripts
mysql_upgrade, mysql_fix_privilege_tables,
mysql_secure_installation ..
7

8. Filesystem Layout - Datafiles
Windows default: C:Program FilesMySQLMySQL Server x.xdata
Tarball default: /usr/local/mysql/data
RPM default: /var/lib/mysql
Databases use “datadir”
Default “mysql” database (SYSTEM Tablespace)
One directory per database
Table frm, data and index files within respective database directories
InnoDB uses “innodb_data_home_dir”
Single tablespace file (ibdata1) located in “datadir” by default
Set multiple datafiles with “innodb_datafile_path”
frm files still created within each database directory under datadir
Respect datadir conventions when using “innodb_file_per_table”
8

9. Filesystem Layout - Log files
Windows Default: C:Program FilesMySQLMySQL Server x.xdata
Tarball default: /usr/local/mysql/data
RPM default: /var/log & /var/lib/mysql
Error Log (Alert Log)
Set path with “log_error”, defaults to [hostname].err in “datadir”
Binary Logs (Archive Redo Logs)
Set with “log_bin”
Record of all INSERT/UPDATE/DELETE activity
<=5.0 Statement Based
>=5.1 Statement Based and Row Based
InnoDB Transaction logs (Online Redo Logs)
ib_logfile[x] set with “innodb_log_files_in_group” (default 2)
Provides “Durability” to ACID compliance
Control “checkpoint” times by altering the size of
“innodb_log_file_size”
9

10. Permissions / Ownership
No concept of “ownership”
Permissions stored in the “mysql” database
“schema” == “database” rather than “users objects”
mysql.user
Username, host, password hash, global privileges, grant option
mysql.db
Database level privileges
mysql.tables_priv
Table level privileges
mysql.columns_priv
Column level privileges
mysql.procs_priv
Procedure / Function privileges
10

11. Backup and Recovery
Cold Backup
Filesystem Snapshot (cp / rsync)
Warm Backup
mysqldump
Hot Backup
mysqldump, mysqlhotcopy
Using Slaves
Recovery tips
11

12. Backup - Cold Backup
Full cold backup
All database directories and contents (including “mysql”)
my.cnf/ini file
If using InnoDB
All InnoDB datafiles
All InnoDB Transaction Redo Log files
Incremental Cold Backup
All of the above as a starting point
Binary logging enabled (”log-bin”)
Only requires the latest binary logs since the last snapshot
Beware of recovery times - applying the binary logs is a lot
slower than file copying
12

13. Backup - Warm Backup
mysqldump
Uses FLUSH TABLES WITH READ LOCK
Locks all other sessions
/* Backup db1, db2 and db3 to the same file, mixed MyISAM / InnoDB / other engines */
mysqldump -u root --opt --databases db1, db2, db3 > /backup/file.sql
/* Backup all databases to seperate files per database schema */
#!/bin/bash
DATABASES=`mysql -u root -N -e 'SHOW DATABASES'`
OPTIONS1='--extended-insert --no-autocommit --quick --set-charset'
OPTIONS2='--disable-keys --skip-add-locks --skip-comments'
DUMPOPTIONS=quot;$OPTIONS1 $OPTIONS2quot;
for D in $DATABASES ;
do
echo dumping $D ;
echo quot;use $D;quot; > $D-data.sql
echo quot;set autocommit=0;quot; >> $D-data.sql
mysqldump -u root $DUMPOPTIONS --databases $D
>> $D-data.sql ;
done
13

14. Backup - Hot Backup
mysqldump
InnoDB only
Uses transactions and multi-versioning
/* Backup InnoDB databases to seperate files per database schema */
#!/bin/bash
DATABASES=`mysql -u root -N -e 'SHOW DATABASES'`
OPTIONS1='--extended-insert --no-autocommit --quick --set-charset --disable-keys'
OPTIONS2=' --skip-add-locks --skip-comments --single-transaction --master-data'
DUMPOPTIONS=quot;$OPTIONS1 $OPTIONS2quot;
for D in $DATABASES ;
do
echo dumping $D ;
echo quot;use $D;quot; > $D-data.sql
echo quot;set autocommit=0;quot; >> $D-data.sql
mysqldump -u root $DUMPOPTIONS --databases $D
>> $D-data.sql ;
done
14

15. Backup - Hot Backup
mysqlhotcopy
MyISAM and ARCHIVE tables only
LOCK TABLES ..; FLUSH TABLES; [cp | scp]; UNLOCK TABLES;
Requires Perl DBI
/* Hot Backup MyISAM / ARCHIVE table files to seperate directories per database
schema */
#!/bin/bash
DATABASES=`mysql -u root -N -e 'SHOW DATABASES'`
DUMPOPTIONS='-u root --method=cp --noindices --flushlog'
for D in $DATABASES ;
do
echo copying $D ;
DIRNAME=$D-`date '+%d%m%y'`
mkdir ~/backup/$DIRNAME
mysqlhotcopy $DUMPOPTIONS $D ~/backup/$DIRNAME
done
15

16. Backup - Slave Hot Backup
Requires no downtime on the master system
Allows full cold backups easily, giving faster recovery times
Adds a server that can also be used to spread load
Master Slave
cp
scp
rsync
server-id 1 server-id 2
LVM
Application Users
mysqldump
mysqlhotcopy
(Dataguard)
Reporting Users
16

17. Recovery Tips
mysqlbinlog
Perform point in time recovery directly to MySQL
mysqlbinlog bin.000001 bin.000002 bin.000003 --stop-datetime=’2006-03-26 12:00:00’ |
mysql -u root -p
Output statements for single databases directly to MySQL
mysqlbinlog bin.000001 bin.000002 bin.000003 --stop-datetime=’2006-03-26 12:00:00’
--database sakila | mysql -u root -p
Output statements to plain text SQL files
mysqlbinlog bin.000001 bin.000002 bin.000003 --stop-datetime=’2006-03-26 12:00:00’
--database sakila > /tmp/sakila-binlog-dump.sql
17

18. Recovery Tips
Always use binary logging if possible
On recovery, make an initial copy of all current database files
Work on original set, leaving copy as secondary backup
Take regular full backups, to minimize recovery time
InnoDB Log file size controls full checkpoint activity
If using mysqlhotcopy, with --noindices, to rebuild indexes:
mysqlcheck --all-databases --auto-repair --use-frm
18

19. Managing Space and Tables
MyISAM Storage Engine
Gathering stats, managing space
InnoDB Storage Engine
Gathering stats, managing space
Partitioning
Partition Management
19

20. Managing MyISAM Space
All table files stored within specific database directory
Row data held within [tablename].MYD
Index data held within [tablename].MYI
Table structure held within [tablename].frm
medusa:/usr/local/mysql/data/sakila root# ls -l film_text*
-rw-rw---- 1 mysql wheel 119616 Apr 4 20:51 film_text.MYD
-rw-rw---- 1 mysql wheel 205824 Apr 4 20:51 film_text.MYI
-rw-rw---- 1 mysql wheel 8642 Apr 4 20:51 film_text.frm
Deleted row space retained for future INSERT/UPDATE
Supports FULLTEXT Indexes (Oracle Text)
Table level locking (SELECT = Shared, INSERT, UPDATE, DELETE = Write)
Data warehousing storage engine
20

21. Managing MyISAM Space
SHOW TABLE STATUS
mysql> SHOW TABLE STATUS LIKE 'film_text'G
*************************** 1. row ***************************
Name: film_text
Variable Length rows (VARCHAR etc.)
Engine: MyISAM
“Fixed” = CHAR etc. static sized
Version: 10
Row_format: Dynamic
Data size in bytes (~117KB)
Rows: 950
Avg_row_length: 119
Data_length: 119616 Max size for the internal row pointer
Max_data_length: 281474976710655
Index_length: 205824 Index size in bytes (~201KB)
Data_free: 6136
Auto_increment: NULL Space reserved but unused
Create_time: 2006-04-03 14:16:02 (~6KB)
Update_time: 2006-04-04 20:51:02
Check_time: 2006-04-04 20:51:17
Collation: utf8_general_ci
Checksum: NULL
Create_options:
Comment:
1 row in set (0.00 sec)
21

22. Managing MyISAM Space
INFORMATION_SCHEMA TABLES (DBA_ / USER_ tables)
SELECT s.schema_name,
CONCAT(IFNULL(ROUND((SUM(t.data_length)+SUM(t.index_length)) /1024/1024,2),0.00),quot;Mbquot;)
total_size,
CONCAT(IFNULL(ROUND(((SUM(t.data_length)+SUM(t.index_length))-SUM(t.data_free))/
1024/1024,2),0.00),quot;Mbquot;) data_used,
CONCAT(IFNULL(ROUND(SUM(data_free)/1024/1024,2),0.00),quot;Mbquot;) data_free,
IFNULL(ROUND((((SUM(t.data_length)+SUM(t.index_length))-SUM(t.data_free)) /((SUM
(t.data_length)+SUM(t.index_length)))*100),2),0) pct_used,
COUNT(table_name) total_tables
FROM INFORMATION_SCHEMA.SCHEMATA s
LEFT JOIN INFORMATION_SCHEMA.TABLES t ON s.schema_name = t.table_schema
WHERE s.schema_name = quot;sakilaquot;
GROUP BY s.schema_name
ORDER BY pct_used DESCG
*************************** 1. row ***************************
schema_name: sakila
total_size: 6.62Mb
data_used: 6.62Mb
data_free: 0.01Mb
pct_used: 99.91
total_tables: 22
1 row in set (0.08 sec)
22

23. Managing MyISAM Space
INFORMATION_SCHEMA TABLES (DBA_ / USER_ tables)
SELECT table_name,
ROUND(((t.data_length+t.index_length)-t.data_free)/(t.data_length+t.index_length)*100) pct_used
FROM information_schema.tables t
WHERE table_schema = 'sakila'
HAVING pct_used < 99
ORDER BY table_nameG
*************************** 1. row ***************************
table_name: film_text
pct_used: 98
1 row in set (0.05 sec)
To reclaim space to the filesystem run “OPTIMIZE TABLE”
Creates a copy of the table, drops the original, and renames the copy
Requires a table lock
If frequent activity on the table run “ANALYZE TABLE”
Requires a table lock
23

24. Managing MyISAM Space
myisamchk -dvv
Should not be used whilst table is being used
LOCK TABLE .. WRITE; or shutdown
medusa:/Users/markleith/mysql/mysql-5.1.7/data/sakila root# ../../bin/myisamchk -dvv film_text
MyISAM file: film_text
Record format: Packed
Character set: latin1_swedish_ci (8)
File-version: 1
Creation time: 2006-04-18 15:57:45
Status: changed
Data records: 1000 Deleted blocks: 0
Datafile parts: 1000 Deleted data: 0
Datafile pointer (bytes): 6 Keyfile pointer (bytes): 6
Datafile length: 119616 Keyfile length: 205824
Max datafile length: 281474976710654 Max keyfile length: 288230376151710719
Recordlength: 782
table description:
Key Start Len Index Type Rec/key Root Blocksize
1 2 2 unique short 1 29696 1024
2 5 254 fulltext ? packed 0 49152 1024
1 4 float 0
Field Start Length Nullpos Nullbit Type
1 1 1
2 2 2 no zeros
3 4 767 varchar
4 771 10 1 1 blob
24

25. Managing InnoDB Space
Row level locking
Supports all transaction isolation levels
Tables, Indexes and rollback created in a single tablespace
Multiple datafiles, with last datafile allowed to autoextend
medusa:/usr/local/mysql/data root# ls -l ib*
-rw-rw---- 1 mysql wheel 5242880 Apr 8 21:25 ib_logfile0
} Redo Logs
-rw-rw---- 1 mysql wheel 5242880 Apr 8 21:25 ib_logfile1
-rw-rw---- 1 mysql wheel 18874368 Apr 8 21:25 ibdata1
} Data Files
-rw-rw---- 1 mysql wheel 10485760 Apr 8 21:25 ibdata2
Clustered Indexes (Index Organized Tables)
Pages and extents managed like a filesystem
Filesystem InnoDB Oracle
Disk Partition Tablespace Tablespace(s)
File Segment (Table/Index) Segment (Table/Index)
Inode Inode
Filesystem Block Extent (64 pages, 1Mb) Extent
Disk Block Page (UNIV_PAGE_SIZE 16Kb) DB_BLOCK_SIZE
25

26. Managing InnoDB Space
SHOW TABLE STATUS
mysql> SHOW TABLE STATUS LIKE 'rental'G
*************************** 1. row ***************************
Name: rental
New 5.0 InnoDB compact row format
Engine: InnoDB
Version: 10
Row_format: Compact
Data size in bytes (~1.5Mb)
Rows: 16305
Avg_row_length: 97
Data_length: 1589248 No Maximum (64Tb for tablespace)
Max_data_length: 0
Index_length: 1261568 Index size in bytes (~1.2Mb)
Data_free: 0
Auto_increment: 16050 Unused space not reported by table
Create_time: 2006-04-03 14:16:02
Update_time: NULL
Check_time: NULL Freespace reported by tablespace
Collation: utf8_general_ci (4Mb)
Checksum: NULL
Create_options:
Comment: InnoDB free: 4096 kB; (`customer_id`)
REFER `sakila/customer`(`customer_id`) ON
1 row in set (0.10 sec)
26

27. Managing InnoDB Space
InnoDB Table and Tablespace Monitors
Dumped to the error log, or console (stdout) if no log-error
Dump the InnoDB internal Data Dictionary information
Switched on with special InnoDB tables
InnoDB Table Monitor
create table innodb_table_monitor (a int) engine = innodb;
InnoDB Tablespace Monitor
create table innodb_tablespace_monitor (a int) engine = innodb;
27

28. Managing InnoDB Space
InnoDB Tablespace Monitor
================================================
060403 14:20:31 INNODB TABLESPACE MONITOR OUTPUT
================================================
FILE SPACE INFO: id 0
size 1152, free limit 832, free extents 3
not full frag extents 4: used pages 202, full frag extents 2
first seg id not used 0 114
SEGMENT id 0 86 space 0; page 209; res 28 used 28; full ext 0
fragm pages 28; free extents 0; not full extents 0: pages 0
SEGMENT id 0 87 space 0; page 209; res 1 used 1; full ext 0
fragm pages 1; free extents 0; not full extents 0: pages 0
SEGMENT id 0 88 space 0; page 209; res 16 used 16; full ext 0
fragm pages 16; free extents 0; not full extents 0: pages 0
SEGMENT id 0 89 space 0; page 209; res 1 used 1; full ext 0
fragm pages 1; free extents 0; not full extents 0: pages 0
SEGMENT id 0 90 space 0; page 209; res 16 used 16; full ext 0
fragm pages 16; free extents 0; not full extents 0: pages 0
SEGMENT id 0 91 space 0; page 209; res 1 used 1; full ext 0
fragm pages 1; free extents 0; not full extents 0: pages 0
SEGMENT id 0 92 space 0; page 209; res 13 used 13; full ext 0
fragm pages 13; free extents 0; not full extents 0: pages 0
......
28

29. Managing InnoDB Space
InnoDB Tablespace Monitor
......
SEGMENT id 0 84 space 0; page 2; res 96 used 53; full ext 0
fragm pages 32; free extents 0; not full extents 1: pages 21
SEGMENT id 0 84 space 0; page 2;
The Internal data dictionary id for the tablespace segment
“space 0” is the system tablespace (ibdata files)
“page 2” is where the inode of the segment is
res 96 used 53;
“res” is total number of reserved pages
“used” is the number of pages with data allocated
full ext 0
The number of extents that are completely used
fragm pages 32;
The first 32 pages are fully allocated
free extents 0;
The number of extents that have no pages at all used
not full extents 1: pages 21
The number of extents that have pages used but are not full
“pages” is how many pages are used within these extents
29

30. Managing InnoDB Space
InnoDB Table Monitor
TABLE: name sakila/rental, id 0 26, columns 11, indexes 5, appr.rows 16305
COLUMNS: rental_id: DATA_INT len 4 prec 0; rental_date: DATA_INT len 8 prec 0; inventory_id: DATA_INT len 3 prec
0; customer_id: DATA_INT len 2 prec 0; return_date: DATA_INT len 8 prec 0; staff_id: DATA_INT len 1 prec 0;
last_update: DATA_INT len 4 prec 0; DB_ROW_ID: DATA_SYS prtype 8 len 6 prec 0; DB_TRX_ID: DATA_SYS prtype 8
len 6 prec 0; DB_ROLL_PTR: DATA_SYS prtype 8 len 7 prec 0;
INDEX: name PRIMARY, id 0 44, fields 1/9, type 3
root page 207, appr.key vals 16305, leaf pages 53, size pages 97
FIELDS: rental_id DB_TRX_ID DB_ROLL_PTR rental_date inventory_id customer_id return_date staff_id last_update
INDEX: name rental_date, id 0 45, fields 3/4, type 2
root page 208, appr.key vals 17655, leaf pages 28, size pages 29
FIELDS: rental_date inventory_id customer_id rental_id
INDEX: name idx_fk_inventory_id, id 0 46, fields 1/2, type 0
root page 210, appr.key vals 4467, leaf pages 16, size pages 17
FIELDS: inventory_id rental_id
INDEX: name idx_fk_customer_id, id 0 47, fields 1/2, type 0
root page 211, appr.key vals 589, leaf pages 16, size pages 17
FIELDS: customer_id rental_id
INDEX: name idx_fk_staff_id, id 0 48, fields 1/2, type 0
root page 212, appr.key vals 1, leaf pages 13, size pages 14
FIELDS: staff_id rental_id
FOREIGN KEY CONSTRAINT sakila/fk_rental_staff: sakila/rental ( staff_id )
REFERENCES sakila/staff ( staff_id )
FOREIGN KEY CONSTRAINT sakila/fk_rental_inventory: sakila/rental ( inventory_id )
REFERENCES sakila/inventory ( inventory_id )
FOREIGN KEY CONSTRAINT sakila/fk_rental_customer: sakila/rental ( customer_id )
REFERENCES sakila/customer ( customer_id )
FOREIGN KEY CONSTRAINT sakila/fk_payment_rental: sakila/payment ( rental_id )
REFERENCES sakila/rental ( rental_id )
30

31. Managing InnoDB Space
InnoDB Table Monitor
TABLE: name sakila/rental, id 0 26, columns 11, indexes 5, appr.rows 16305
COLUMNS: rental_id: DATA_INT len 4 prec 0; rental_date: DATA_INT len 8 prec 0; inventory_id:
DATA_INT len 3 prec 0; customer_id: DATA_INT len 2 prec 0; return_date: DATA_INT len 8 prec 0; staff_id:
DATA_INT len 1 prec 0; last_update: DATA_INT len 4 prec 0; DB_ROW_ID: DATA_SYS prtype 8 len 6 prec 0;
DB_TRX_ID: DATA_SYS prtype 8 len 6 prec 0; DB_ROLL_PTR: DATA_SYS prtype 8 len 7 prec 0;
“len” is column length in bytes, “prec” is the columns precision (DECIMAL etc.)
“DB_ROW_ID”, “DB_TRX_ID” and “DB_ROLL_PTR” internal columns for transactions /
multi-versioning
INDEX: name PRIMARY, id 0 44, fields 1/9, type 3
root page 207, appr.key vals 16305, leaf pages 53, size pages 97
FIELDS: rental_id DB_TRX_ID DB_ROLL_PTR rental_date inventory_id customer_id return_date staff_id last_update
“fields 1/9” is fields specifically specified in the index (1) and total fields in the index (9)
“type” is index type: 3 = PRIMARY, 2 = UNIQUE, 0 = KEY, 1 = AUTO GENERATED PK
“leaf pages 53” is the number of pages with data allocated (”used” in tablespace monitor)
“size pages 97” is the total number of allocated pages (”res” in tablespace monitor)
Rows: 16305
Avg_row_length: 97 16,384 * 97 = 1,589,248 (1.5Mb)
Data_length: 1589248
Max_data_length: 0 16,384 * (29+17+17+14) = 1,261,568 (1.2mb)
Index_length: 1261568
16,384 * (97-53) = 720,896 (~700Kb)
Data_free: 0
31

32. Managing InnoDB Space
Allocates the first 32 pages individually
After 32 pages allocated, allocates 1Mb extents
To reclaim space to the tablespace run “OPTIMIZE TABLE”
Reorganization process similar to MyISAM
Requires a table lock
“ANALYZE TABLE” rarely needed, as InnoDB updates stats
Not Uniform extent allocation, fragmentation highly possible
To reorganize the tablespace:
mysqldump all tables
Stop MySQL
mv the InnoDB tablespace datafiles and log files to a backup location
Start MySQL
Load the mysqldump
32

33. Partitioning (5.1)
No extra costs
All storage engines support partitioning
“Local” indexes only
Indexes only created locally to each partition
“Global” indexes scheduled for 5.2
Indexes created across the entire partitioned table
Partition pruning already available at the optimizer level
Allow far greater table maintenance flexibility, with partition
level locks
33

34. Partitioning (5.1)
RANGE partitioning: (As in Oracle 8i RANGE partitions)
Assigns rows to partitions based on column values falling within a given range.
LIST partitioning: (As in Oracle 9i LIST partitions)
Similar to partitioning by range, except that the partition is selected based on
columns matching one of a set of discrete values.
HASH partitioning: (Not possible in Oracle)
A partition is selected based on the value returned by a user-defined expression
that operates on column values in rows to be inserted into the table. The function
may consist of any expression valid in MySQL that yields a non-negative integer
value.
KEY partitioning: (As in Oracle 8i HASH partitions)
Similar to partitioning by hash, except that only one or more columns to be
evaluated are supplied, and the MySQL server provides its own hashing function.
These columns can contain other than integer values, since the hashing function
supplied by MySQL guarantees an integer result regardless of the column data
type.
Subpartitioning: (As in Oracle 9i composite partitions)
Subpartition tables that are partitioned by RANGE or LIST. Subpartitions may use
either HASH or KEY partitioning.
34

35. Partitioning (5.1)
Moving to Partitioned tables
PARTITION key must be a part of the PRIMARY KEY, if any, if not, any column
PARTITION key must be on an INT column, or expression returning an INT
Do not support FOREIGN KEY constraints
CREATE TABLE `RENTAL` (
`rental_id` int(11) NOT NULL auto_increment,
`rental_date` datetime NOT NULL,
`inventory_id` mediumint(8) unsigned NOT NULL,
`customer_id` smallint(5) unsigned NOT NULL,
`return_date` datetime default NULL,
`staff_id` tinyint(3) unsigned NOT NULL,
`last_update` timestamp NOT NULL default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP,
PRIMARY KEY (`rental_id`),
UNIQUE KEY `rental_date` (`rental_date`,`inventory_id`,`customer_id`),
KEY `idx_fk_inventory_id` (`inventory_id`),
KEY `idx_fk_customer_id` (`customer_id`),
KEY `idx_fk_staff_id` (`staff_id`),
CONSTRAINT `fk_rental_staff` FOREIGN KEY (`staff_id`) REFERENCES `staff` (`staff_id`) ON UPDATE CASCADE,
CONSTRAINT `fk_rental_inventory` FOREIGN KEY (`inventory_id`) REFERENCES `inventory` (`inventory_id`) ON
UPDATE CASCADE,
CONSTRAINT `fk_rental_customer` FOREIGN KEY (`customer_id`) REFERENCES `customer` (`customer_id`) ON
UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8
35

36. Partitioning (5.1)
Moving to Partitioned tables
DROP TABLE rental_parts;
CREATE TABLE `rental_parts` (
`rental_id` int(11) NOT NULL auto_increment,
`rental_date` datetime NOT NULL,
`inventory_id` mediumint(8) unsigned NOT NULL,
`customer_id` smallint(5) unsigned NOT NULL,
`return_date` datetime default NULL,
`staff_id` tinyint(3) unsigned NOT NULL,
`last_update` timestamp NOT NULL default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP,
PRIMARY KEY (`rental_id`, `rental_date`),
UNIQUE KEY `rental_date` (`rental_date`,`inventory_id`,`customer_id`),
KEY `idx_inventory_id` (`inventory_id`),
KEY `idx_customer_id` (`customer_id`),
KEY `idx_staff_id` (`staff_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8
PARTITION BY RANGE (YEAR(`rental_date`))(
PARTITION rental_2002 VALUES LESS THAN (2003),
PARTITION rental_2003 VALUES LESS THAN (2004),
PARTITION rental_2004 VALUES LESS THAN (2005),
PARTITION rental_2005 VALUES LESS THAN (2006),
PARTITION rental_2006 VALUES LESS THAN MAXVALUE
);
INSERT INTO rental_parts (SELECT * FROM rental);
DROP TABLE rental;
RENAME TABLE rental_parts TO rental;
36

37. Partitioning (5.1)
INFORMATION_SCHEMA.PARTITIONS
SELECT table_schema, table_name, partition_name, table_rows, data_length, index_length
FROM information_schema.partitions
WHERE table_name = 'rental’
AND table_schema = ‘sakila’
************************** 1. row *************************** *************************** 4. row ***************************
table_schema: sakila table_schema: sakila
table_name: rental table_name: rental
partition_name: rental_2002 partition_name: rental_2005
table_rows: 0 table_rows: 16272
data_length: 16384 data_length: 1589248
index_length: 65536 index_length: 1818624
*************************** 2. row *************************** *************************** 5. row ***************************
table_schema: sakila table_schema: sakila
table_name: rental table_name: rental
partition_name: rental_2003 partition_name: rental_2006
table_rows: 0 table_rows: 182
data_length: 16384 data_length: 16384
index_length: 65536 index_length: 65536
*************************** 3. row *************************** 5 rows in set (0.02 sec)
table_schema: sakila
table_name: rental
partition_name: rental_2004
table_rows: 0
data_length: 16384
index_length: 65536
37

38. Partitioning (5.1)
Partition Management - ALTER TABLE
REBUILD PARTITION (No Oracle equivalent)
Used to rebuild/reorganize a partition
ALTER TABLE rental REBUILD PARTITION rental_2005;
OPTIMIZE PARTITION (No Oracle equivalent)
Used like OPTIMIZE TABLE for each storage engine, at the partition level
ALTER TABLE rental OPTIMIZE PARTITION rental_2004;
ANALYZE PARTITION (analyze table emp partition(p1) compute statistics;)
Reads and stores the key distributions for partitions
ALTER TABLE rental ANALYZE PARTITION rental_2005;
CHECK PARTITION (No Oracle equivalent)
Checks specific partitions for errors (like CHECK TABLE)
ALTER TABLE rental CHECK PARTITION rental_2003;
REPAIR PARTITION (No Oracle equivalent)
Used for MyISAM partitions, if they become corrupt (like REPAIR TABLE)
ALTER TABLE rental REPAIR PARTITION rental_2003;
38

39. Partitioning (5.1)
Partition Management - ALTER TABLE
ADD PARTITION (Same as Oracle)
Add a partition to the table (to the end of the
ALTER TABLE rental ADD PARTITION
(PARTITION rental_2007 VALUES LESS THAN (2008);
DROP PARTITION (Same as Oracle)
Remove a partition from the table
ALTER TABLE rental DROP PARTITION rental_2002;
REORGANIZE PARTITION (ALTER TABLE .. SPLIT / MERGE PARTITION)
Split a partition in to multiple partitions, or merge several partitions in to one
ALTER TABLE rental REORGANIZE PARTITION rental_2002 INTO (
PARTITION rental_pre_2002 VALUES LESS THAN (2002),
PARTITION rental_2002 VALUES LESS THAN (2003));
ALTER TABLE rental REORGANIZE PARTITION rental_pre_2002, rental_2002
INTO (PARTITION rental_pre_2003 VALUES LESS THAN (2003));
39

40. Managing Memory
SHOW [GLOBAL | SESSION] STATUS
MyISAM Key Cache
InnoDB Buffer Pool
Query Cache
Thread Buffers
40

41. Managing Memory
SHOW [GLOBAL | SESSION] STATUS [LIKE ‘string’]
Provides session and global level server statistics
Gives information about various aspects of the server such as locks,
memory usage, disk usage, network activity etc.
Akin to various of the V$ views in parts
Reset statistics with “FLUSH STATUS”
mysql> SHOW STATUS;
+-------------------------------------+-----------------+
| Variable_name | Value |
+-------------------------------------+-----------------+
| Aborted_clients |0 |
| Aborted_connects |0 |
| Bytes_received | 155372598 |
| Bytes_sent | 1176560426 |
| Connections | 30023 |
...
| Created_tmp_disk_tables | 0 |
| Created_tmp_tables | 8340 |
| Created_tmp_files | 60 |
41

42. Managing Memory
MyISAM Key Cache
Caches only MyISAM index data
Key status indicators:
Key_reads - Index blocks read from disk
Key_read_requests - Index blocks read from cache
Key_writes - Index blocks written on disk
Key_write_requests - Index blocks written within cache
Monitor overall usage with a hit ratio indicator
SHOW GLOBAL STATUS LIKE ‘key_read%’;
100-((key_reads/key_read_requests)*100)
Set with “key_buffer_size” in my.cnf, or interactively:
SET GLOBAL key_buffer_size = 50*1024*1024;
Current maximum 4Gb
42

43. Managing Memory
InnoDB Buffer Pool
Caches InnoDB table and index data
Key status indicators (5.0 or greater):
Innodb_buffer_pool_reads - Pages read from disk
Innodb_buffer_pool_read_requests - Pages read from the cache
Innodb_buffer_pool_wait_free - Number of waits to create or flush page
Innodb_buffer_pool_read_ahead_seq - Incremented for full table scans
Monitor overall usage with a hit ratio indicator
SHOW GLOBAL STATUS LIKE ‘innodb_buffer_pool_read%’;
100-((Innodb_buffer_pool_reads/Innodb_buffer_pool_read_requests)*100)
Set with “innodb_buffer_pool_size” in my.cnf
Not a dynamic variable (requires a restart)
Typically 50-80% of dedicated server’s available RAM
43

44. Managing Memory
Query Cache
Caches query result sets as pre-formed network packets
Key status indicators:
Qcache_hits - Queries satisfied from the cache
QCache_inserts - Query result sets added to the cache
Qcache_lowmem_prunes - Query results flushed due to lack of memory
Qcache_free_memory - Bytes free
Monitor overall usage with a hit ratio indicator
100-((Qcache_inserts/Qcache_hits)*100)
Set with “query_cache_size” and “query_cache_type”
SET GLOBAL query_cache_size = 32*1024*1024;
Control block allocation size with “query_alloc_block_size”
Control size of result sets cached with “query_cache_limit”
44

45. Managing Memory
Per Thread Buffers
Possible to set dynamically at the session level with “SET SESSION variable = ..”
sort_buffer_size
Allocated per thread for each sort operation (ORDER BY / GROUP BY)
Values larger than 2-4Mb rarely benefit performance
Monitor for high “Sort_merge_passes” in SHOW GLOBAL STATUS
read_rnd_buffer_size
Used when reading sorted rows after an ORDER BY on an indexed column
Larger result sets get better performance from larger buffer size
Leave GLOBAL default and use SET SESSION when needed for large queries
read_buffer_size
Allocated per thread for each full MyISAM table scan
Values larger than 2-4Mb rarely benefit performance
Monitor for high “Handler_read_rnd_next” / “Select_scan”
join_buffer_size
Allocated per thread for each JOIN causing a full table scan
Possible many allocated per thread with complex/multiple joins
Values larger than 2-4Mb rarely benefit performance
45

46. Managing Memory
Per Thread Buffers
tmp_table_size
Allocated per thread for each complex GROUP BY or subquries etc.
Monitor with “Created_tmp_tables” and “Created_tmp_disk_tables”
32-64Mb depending on memory available
binlog_cache_size
Also allocated per thread
Caches Binary Log entries for multiple statement transactions
Monitor with “Binlog_cache_use” and “Binlog_disk_cache_use” satus variables
Limit with “max_binlog_cache_size” system variable
thread_cache_size
GLOBAL level variable
Caches threads/sessions with an already allocated stack for faster connections
When sessions disconnect they have their buffers flushed and are re-added
Monitor with ratio of “Threads_created” to “Connections”
46

47. Tracing Sessions / Auditing
SHOW FULL PROCESSLIST (V$SESSION)
PROCESS privilege required to view the full session list
Use FULL keyword to include currently executing SQL
mysql> SHOW FULL PROCESSLIST;
+----+------+-----------------------+---------+------------------+--------------+-------------+----------------------------------------+
| Id | User | Host | db | Command | Time | State | Info |
+----+------+-----------------------+---------+------------------+---------------+-------------+---------------------------------------+
| 1 | root | localhost:32820 | merlin | Sleep | 1| | NULL |
| 3 | root | localhost:32822 | merlin | Sleep | 507 | | NULL |
| 4 | root | localhost:32823 | merlin | Sleep | 507 | | NULL |
| 5 | root | localhost:32824 | merlin | Sleep | 506 | | NULL |
| 6 | root | localhost:32826 | merlin | Sleep | 21207 | | NULL |
| 7 | root | localhost:32827 | merlin | Query | 0 | Sending data | SELECT data_id,value |
FROM `dc_INTEGER` WHERE `begin_time` =(SELECT MAX(`begin_time`) FROM `dc_INTEGER` |
WHERE `collect_id`=90) AND `collect_id`=90 FOR UPDATE |
| 16 | root | localhost:33447 | NULL | Sleep | 3| | NULL |
| 19 | root | localhost:48885 | merlin | Sleep | 7| | NULL |
| 27 | root | localhost | NULL | Query | 0 | NULL | SHOW FULL PROCESSLIST |
+----+------+-----------------------+---------+------------------+--------------+-------------+----------------------------------------+
9 rows in set (0.00 sec)
47

48. Tracing Sessions / Auditing
PROCESSLIST states
Sleeping - The thread is idle
Opening Tables - Trying to open a new table
Copying to tmp table - Creating in memory temporary table
Copying to tmp table on disk - Creating disk based temporary table
Sorting for group - Performing a GROUP BY operation
Sorting for order - Performing an ORDER BY operation
Sending Data - Processing and returning SELECT results
Updating - Currently updating row values
Writing to net - Server is writing packets to the client
Locked - The session is currently blocked by another sessions lock(s)
Killed - Kill flag set, waiting for next opportunity to release thread
39

49. Tracing Sessions / Auditing
General Query Log
Records all connections and statements, successful or failed
Set with the “log” server variable
log=/var/log/mysql-query.log
Does incur a slight performance overhead
[markleith@medusa:~] $ sudo tail -n 15 mysql/mysql-5.1.7/data/general.log
Password:
./mysql-5.1.7/bin/mysqld-debug, Version: 5.1.7-beta-debug-log. started with:
Tcp port: 5017 Unix socket: /Users/markleith/mysql/mysql-5.1.7.sock
Time Id Command Argument
060419 11:58:49 1 Connect root@localhost on
060419 11:58:57 1 Query SELECT DATABASE()
1 Init DB sakila
060419 11:59:00 1 Query show tables
060419 11:59:19 1 Query desc staff
060419 12:00:04 1 Query select staff_id, first_name, last_name, email, username, password
from staff
49

50. Tracing Sessions / Auditing
New in 5.1 (True V$SESSION, V$SQLTEXT, sys.aud$)
INFORMATION_SCHEMA.PROCESSLIST
mysql.general_log - Set with “--log-output=TABLE,FILE” (or either)
mysql.slow_log - Set with “--log-output=TABLE,FILE” (or either)
mysql> SELECT * FROM INFORMATION_SCHEMA.PROCESSLIST;
+----+---------+--------------+---------+----------------+---------+--------------+------------------------------------------------------------------------------------+
| ID | USER | HOST | DB | COMMAND | TIME | STATE | INFO |
+----+---------+--------------+---------+----------------+---------+--------------+------------------------------------------------------------------------------------+
| 2 | root | localhost | | Query |0 | preparing | SELECT * FROM INFORMATION_SCHEMA.PROCESSLIST |
| 1 | root | localhost | sakila | Sleep | 2434 | | |
+----+---------+--------------+---------+----------------+---------+--------------+------------------------------------------------------------------------------------+
2 rows in set (0.00 sec)
mysql> SELECT p.id, g.event_time, p.user, p.host, g.command_type, replace(g.argument,'n', '') statement
-> FROM information_schema.processlist p
-> JOIN mysql.general_log g ON p.id = g.thread_id
-> WHERE p.id = 1 AND g.event_time > NOW() - INTERVAL 3 HOUR ORDER BY event_time;
+----+----------------------------+------+--------------+----------------+------------------------------------------------------------------------------------------------------------+
| id | event_time | user | host | command_type | statement |
+----+----------------------------+------+--------------+----------------+------------------------------------------------------------------------------------------------------------+
| 1 | 2006-04-19 11:58:49 | root | localhost | Connect | root@localhost on |
| 1 | 2006-04-19 11:58:57 | root | localhost | Query | SELECT DATABASE() |
| 1 | 2006-04-19 11:58:57 | root | localhost | Init DB | sakila |
| 1 | 2006-04-19 11:59:00 | root | localhost | Query | show tables |
| 1 | 2006-04-19 11:59:19 | root | localhost | Query | desc staff |
| 1 | 2006-04-19 12:00:04 | root | localhost | Query | select staff_id, first_name, last_name, email, username, passwordfrom staff |
+----+----------------------------+------+--------------+----------------+------------------------------------------------------------------------------------------------------------+
51

51. Tracing Sessions / Auditing
Triggers
DML triggers availble
[BEFORE | AFTER] [INSERT | UPDATE | DELETE]
System triggers such as “LOGON” not yet available
Only one trigger of each type allowed (i.e. BEFORE UPDATE)
Can perform multiple actions between BEGIN ... END blocks
CREATE TABLE audit_payment (
audit_id INT AUTO_INCREMENT PRIMARY KEY,
payment_id INT,
new_staff_id TINYINT,
old_staff_id TINYINT,
new_amount DECIMAL(5,2),
old_amount DECIMAL(5,2),
updated_by VARCHAR(64),
update_time DATETIME
);
CREATE TRIGGER tr_audit_payment AFTER UPDATE ON payment
FOR EACH ROW
INSERT INTO audit_payment VALUES
(NULL,OLD.payment_id,NEW.staff_id,OLD.staff_id,NEW.amount,OLD.amount,CURRENT_USER(),NOW());
52

52. Tracing Sessions / Auditing
Triggers
mysql> select * from payment where payment_id = 16049;
+-----------------+-------------------+-----------+-------------+------------+----------------------------+-----------------------------+
| payment_id | customer_id | staff_id | rental_id | amount | payment_date | last_update |
+-----------------+-------------------+-----------+-------------+------------+----------------------------+-----------------------------+
| 16049 | 599 |2 | 15725 | 2.99 | 2005-08-23 11:25:00 | 2006-02-15 22:24:13 |
+-----------------+-------------------+-----------+-------------+------------+----------------------------+-----------------------------+
1 row in set (0.00 sec)
mysql> UPDATE payment SET amount = 1.99 WHERE payment_id = 16049;
Query OK, 1 row affected (0.03 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> select * from audit_paymentG
*************************** 1. row ***************************
audit_id: 1
payment_id: 16049
new_staff_id: 2
old_staff_id: 2
new_amount: 1.99
old_amount: 2.99
updated_by: root@localhost
update_time: 2006-04-19 13:33:48
1 row in set (0.00 sec)
53

53. Monitoring Tools
MySQL Network 2.0
Server Overview
54

54. Monitoring Tools
Alert overview
55

55. Monitoring Tools
Alert History
Graphing/Trending
56

56. Connecting Oracle to MySQL
Heterogeneous Services
Connects Oracle to MySQL via MyODBC
Can create database links from Oracle
Oracle -> MySQL only
Install and configure MyODBC
Create and edit $ORACLE_HOME/hs/admin and add:
/* Replace quot;MySQLquot; below with your DSN specified within your MyODBC setup */
HS_FDS_CONNECT_INFO = MySQL
HS_FDS_TRACE_LEVEL = OFF
Edit $ORACLE_HOME/network/admin/listener.ora and add:
(SID_DESC =
(PROGRAM = hsodbc)
(ORACLE_HOME = oracle/product/92) /* Your $ORACLE_HOME */
(SID_NAME = MySQL) /* Your DSN */
)
57

57. Connecting Oracle to MySQL
Heterogeneous Services
Add the following to the tnsnames.ora file:
MYSQL =
(DESCRIPTION=
(ADDRESS=(PROTOCOL=tcp)(HOST=localhost)(PORT=1521))
(CONNECT_DATA=(SID=MYSQL))
(HS=OK)
)
Reload your Oracle listener (lsnrctl reload) and then log
onto to the Oracle database. To set up the database link:
CREATE DATABASE LINK mysql
CONNECT TO quot;my_userquot; IDENTIFIED BY quot;my_passwordquot;
USING 'mysql';
58

58. Connecting Oracle to MySQL
Heterogeneous Services
SQL> COUNT(*) FROM film@mysql;
COUNT(*)
----------
1000
SQL> DESC film@mysql5;
Name Null? Type
----------------------------------------- -------- ----------------------------
film_id NUMBER(10)
category_id NOT NULL NUMBER(10)
title NOT NULL VARCHAR2(27)
description LONG
rental_duration NOT NULL NUMBER(3)
length NUMBER(10)
rating CHAR(5)
SQL>INSERT INTO film@mysql5 VALUES (1000000,1,'test','test',1,1,'PG');
1 row created.
---change prompts---
mysql> USE sakila
mysql> SELECT max(film_id) FROM film;
+------------------+
| max(film_id) |
+------------------+
| 1000000 |
+------------------+
59

59. Questions?
60