mysql for the oracle dba - object management

4a1Copyright 2008 MySQL Inc MySQL The Best Online Database for modern applications

4a. MySQL Object ManagementVersion 1.2

4a. MySQL Object Management

for the Oracle DBA

Ronald BradfordSenior Consultant

MySQL IncJanuary 2008



Agenda

GOAL: Creating and Managing MySQL Objects SQL Object Types Creating Objects Managing Objects MySQL Data Dictionary



SQL Object Types



Object Types User Database (Schema) Tablespace / Data File Table / Column Index View Trigger Stored Procedure Stored Function User Defined Function (UDF)

No SequencesNo SnapshotsNo Synonyms



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



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



Indexes

Default Index type is BTREE Memory has HASH & BTREE Indexes MyISAM has a FULLTEXT Index



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.



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



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



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



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



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)



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



MySQL Data Dictionary



MySQL Data Dictionary

Two Present Sources Privilege/System Tables 'mysql' database Information Schema



'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)



INFORMATION_SCHEMA5.0 SCHEMATA, TABLES, COLUMNS, TABLE_CONSTRAINTS,

VIEWS, STATISTICS USER_PRIVILEGES,

SCHEMA_PRIVILEGES,TABLE_PRIVILIGES, COLUMN_PRIVILEGES

CHARACTER_SETS, COLLATIONS, COLLATION_CHARACTER_SET_APPLICIBILITY

ROUTINES, PROFILING5.1 KEY_COLUMN_USAGE,PLUGINS,ENGINES,PARTITIONS,EVENT

S,FILES, REFERENTIAL_CONSTRAINTS, PROCESSLIST, GLOBAL_STATUS,

SESSION_STATUS,GLOBAL_VARIABLES,SESSION_VARIABLES 6.0 FALCON_



INFORMATION_SCHEMA ExamplesTable 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;



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';



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 DESC\G



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mysql for the oracle dba - object management

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