Example section on MySQL for the Oracle DBA 1 day bootcamp. In object management we look at the key SQL objects including what differs with Oracle and what is Oracle specific functionality. We also look at the MySQL data dictionary, the INFORMATION_SCHEMA

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4a. MySQL Object Management
Version 1.2
4a. MySQL Object Management
for the Oracle DBA
Ronald Bradford
Senior Consultant
MySQL Inc
January 2008

2. 4a­2Copyright 2008 MySQL Inc MySQL ­ The Best Online Database for modern applications
4a. MySQL Object Management
Version 1.2
Agenda
GOAL: Creating and Managing MySQL Objects

SQL Object Types

Creating Objects

Managing Objects

MySQL Data Dictionary

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4a. MySQL Object Management
Version 1.2
SQL Object Types

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4a. MySQL Object Management
Version 1.2
Object Types

User

Database (Schema)

Tablespace / Data File

Table / Column

Index

View

Trigger

Stored Procedure

Stored Function

User Defined Function (UDF)
No Sequences
No Snapshots
No Synonyms

5. 4a­5Copyright 2008 MySQL Inc MySQL ­ The Best Online Database for modern applications
4a. MySQL Object Management
Version 1.2
Users

There is no concept of user ownership within MySQL

All objects are part of a database (or 'schema')

Users only have object privileges assigned to them

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4a. MySQL Object Management
Version 1.2
Table / Column

Table Name is case sensitive (by default)

Reserved Words are permitted (appropriately quoted)
http://dev.mysql.com/doc/refman/5.1/en/reserved­words.html

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4a. MySQL Object Management
Version 1.2
Indexes

Default Index type is BTREE

Memory has HASH & BTREE Indexes

MyISAM has a FULLTEXT Index

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4a. MySQL Object Management
Version 1.2
Views

Updatable and non­updatable views supported

view and table names must be unique

DEFINER clause allows view to run as the calling user,
or another defined user

View restrictions

cannot contain a subquery in the FROM clause.

cannot refer to system or user variables.

cannot refer to prepared statement parameters.

Within a stored routine, the definition cannot refer to routine
parameters or local variables.

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4a. MySQL Object Management
Version 1.2
Views

View restrictions (cont)

Any table or view referred to in the definition must exist.
However after creation, underlying objects can be dropped or
modified. View is not invalidated, but will throw error on usage.

The definition cannot refer to a TEMPORARY table

You cannot create a TEMPORARY view.

The tables named in the view definition must already exist.

You cannot associate a trigger with a view.

View algorithms

MERGE

TEMPTABLE

UNDEFINED

Supports WITH CHECK OPTION

Do not support Materialized Views

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4a. MySQL Object Management
Version 1.2
Triggers

DML triggers only ­ no system triggers

[BEFORE | AFTER] [INSERT | UPDATE | DELETE]

Only one of each trigger type supported

FOR EACH ROW, no FOR EACH STATEMENT

No INSTEAD OF

No WHEN Condition

NEW.col and OLD.col syntax

CALL statement for SP not permitted

No statements that implicitly or explicitly COMMIT |
ROLLBACK

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4a. MySQL Object Management
Version 1.2
Stored Procedures

PL/PSM (Persistent Stored Modules)

Non scrollable, read only cursors

Support for most loop types (FOR loops not yet)

DEFINER clause allows stored procedure to run as the
calling user, or another defined user

No packages support

No anonymous blocks

No concept of dependency within MySQL

Stored procedures are not required for high
performance within MySQL

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4a. MySQL Object Management
Version 1.2
User Defined Functions (UDF)

Added as Object Files

Compiled and available on permanent basis
mysql> create function logger returns integer soname 'syslogudf.so';
mysql> select logger('logging from ' + version());
http://dev.mysql.com/doc/refman/5.0/en/adding­functions.html

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4a. MySQL Object Management
Version 1.2
MySQL Create Object Limitations

No online ALTER Table

No online Add Tablespace Data File

Online Add Index (5.1)

Online Add Enum Value (5.1)

Online Add Column (5.1 ­ MyISAM)

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4a. MySQL Object Management
Version 1.2
MySQL Auto Increment
Replacement for SEQUENCE

Limitations

Only one per table

No System wide concept

No Get Next capability

Get Value after Insert with LAST_INSERT_ID()

No required in INSERT, or NULL can be used

No persistence of true max value used across restart

exists in Falcon 6.0
http://dev.mysql.com/doc/refman/5.0/en/example­auto­increment.html

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4a. MySQL Object Management
Version 1.2
MySQL Data Dictionary

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4a. MySQL Object Management
Version 1.2
MySQL Data Dictionary
Two Present Sources

Privilege/System Tables ­ 'mysql' database

Information Schema

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4a. MySQL Object Management
Version 1.2
'mysql' database

Privileges (host, db ,user, tables_priv, columns_priv,procs_priv)

Help (help_category, help_keyword, help_relation, help_topic)

Time zones (time_zone, time_zone_name,
time_zone_leap_second, time_zone_transition,
time_zone_transition_type)

Procedure & Function (proc, func)

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4a. MySQL Object Management
Version 1.2
INFORMATION_SCHEMA
5.0

SCHEMATA, TABLES, COLUMNS, TABLE_CONSTRAINTS,
VIEWS, STATISTICS

USER_PRIVILEGES,
SCHEMA_PRIVILEGES,TABLE_PRIVILIGES,
COLUMN_PRIVILEGES

CHARACTER_SETS, COLLATIONS,
COLLATION_CHARACTER_SET_APPLICIBILITY

ROUTINES, PROFILING
5.1

KEY_COLUMN_USAGE,PLUGINS,ENGINES,PARTITIONS,EVENT
S,FILES, REFERENTIAL_CONSTRAINTS,

PROCESSLIST, GLOBAL_STATUS,
SESSION_STATUS,GLOBAL_VARIABLES,SESSION_VARIABLES
6.0

FALCON_

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4a. MySQL Object Management
Version 1.2

20. 4a­20Copyright 2008 MySQL Inc MySQL ­ The Best Online Database for modern applications
4a. MySQL Object Management
Version 1.2
INFORMATION_SCHEMA Examples
Table Disk Size for given schema
select table_name, table_rows, avg_row_length,
data_length/1024/1024 as data_mb,
index_length/1024/1024 as index_mb
from information_schema.tables
where table_schema='dbname'
order by 4 desc;

21. 4a­21Copyright 2008 MySQL Inc MySQL ­ The Best Online Database for modern applications
4a. MySQL Object Management
Version 1.2
INFORMATION_SCHEMA Examples
SELECT TABLE_SCHEMA, SUM((DATA_LENGTH + INDEX_LENGTH) /
(1024 * 1024)) AS SIZE_MB FROM
INFORMATION_SCHEMA.TABLES
GROUP BY TABLE_SCHEMA ORDER BY SIZE_MB DESC
SELECT ROUTINE_TYPE, ROUTINE_NAME FROM
INFORMATION_SCHEMA.ROUTINES WHERE
ROUTINE_SCHEMA='dbname';
SELECT
TRIGGER_NAME,EVENT_MANIPULATION,EVENT_OBJECT_TABLE,
ACTION_STATEMENT FROM INFORMATION_SCHEMA.TRIGGERS WHERE
TRIGGER_SCHEMA='dbname';
SELECT CONCAT('DROP TABLE ',table_name,';')
INTO OUTFILE '/sql/drop_tables.sql'
FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA =
'dbname';

22. 4a­22Copyright 2008 MySQL Inc MySQL ­ The Best Online Database for modern applications
4a. MySQL Object Management
Version 1.2
INFORMATION_SCHEMA Examples
SELECT s.schema_name, CONCAT(IFNULL(ROUND((SUM(t.data_length)+
SUM(t.index_length))/1024/1024,2),0.00),'Mb')
total_size, CONCAT(IFNULL(ROUND(((SUM(t.data_length)
+SUM(t.index_length))­SUM(t.data_free))/1024/1024,2),
0.00),'Mb') data_used,
CONCAT(IFNULL(ROUND(SUM(data_free)/1024/1024,2),0.00),'Mb')
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 != 'information_schema'
GROUP BY s.schema_name ORDER BY pct_used DESCG

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4a. MySQL Object Management
Version 1.2
Questions?