Download Peace of mind: Quick Tour through the New SQL server

PEACE OF MIND:
QUICK TOUR THROUGH THE NEW
SQL SERVER MIGRATION ASSISTANT (SSMA)
Dmitry Balin
DB Best Technologies
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Confidential and Proprietary © 2011 Microsoft
Last Updated: Monday, May 22, 2017
SESSION OBJECTIVES AND TAKEAWAYS
• Why Migrate to SQL Server
• Database and Application Migration Process
• SQL Server Migration Assistant (SSMA)
• Database Migration Challenges
• Migration Best Practices
• Resources
WHY MIGRATE TO SQL SERVER
What some of our customers say …
We moved nine-terabyte system migrated from Oracle using
SSMA that resulted in significant TCO savings.
We were going for Better - Faster - Cheaper. And we attained
all three!
We not only reduced annual licensing costs but we also
improved uptime.
We improved development productivity and lowered cost
after migrating our mission-critical system from Oracle.
DATABASE AND APPLICATION MIGRATION PROCESS
•
Database Discovery
•
Non-code requirements (HADR, Perf,
•
Migration Impact Assessment
Schema Conversion
Data Migration
Embedded SQL Statements
•
•
•
•
•
locale, maintenance, dependencies, etc.)
Database connectivity
User Login and Permission
DEMO
SQL Server Migration Assistant
SQL SERVER MIGRATION ASSISTANT
Automates and simplifies all phases of database migration
Migration Analyzer
Assess migration complexity
Schema Converter
Convert schema and business logic
Data Migrator
Migration Tester
Migrate data
Validate converted database code
Support migration from Oracle, Sybase, MySQL and Access databases
to SQL Server
DATABASE MIGRATION CHALLENGES
Feature and dialect differences requires non-direct mapping and emulation
User
Db
SysDb
PL/SQL
Master
DEMO
A Closer Look at Schema Conversion
WHAT’S NEW IN SSMA
SSMA 5.0
 Migration to SQL Server
2012
 Multi-thread data
migration
 Globalization support
 Oracle User Defined
Type discovery
 Sybase migration
enhancements
SSMA 5.1
MIGRATION BEST PRACTICES
Customize SSMA project settings
•
•
•
•
65 configuration options for Oracle Migration
55 configuration options for Sybase Migration
65 configuration options for MySQL Migration
25 configuration options for Access Migration
Testing and validation
• Allocate ~30% of the project effort to testing and validation of the converted
code
• Use tools (e.g. DB Best Database Compare Suite) to validate schema and data
conversion
• Performance testing and benchmarking is key metrics for project success
Application conversion
• Analyze and identify all applications interfacing with the Oracle database
• Look for embedded SQL statements spread across the application code
Optimize infrastructure, people and processes
• Server, storage, security, maintenance, monitoring, troubleshooting
• Advanced level training/workshops
RESOURCES
• Database Migration Resources & Whitepaper
http://www.microsoft.com/sqlserver/en/us/productinfo/migration.aspx
• Free Technical Product support
[email protected] (FREE technical support from Microsoft
CSS)
• Discussion Forums
http://social.msdn.microsoft.com/Forums/en-US/sqlservermigration
• SSMA Team Blog
http://blogs.msdn.com/b/ssma/
• Additional migration resources and tools
http://www.DBBest.com
FURTHER. FORWARD. FASTER.
•Learn more
Visit the Microsoft Virtual Academy
Free technical SQL Server training courses
•Get more
Download SQL Server 2012 Trial Software
180-day evaluation of SQL Server 2012
•Do more
Participate in virtual launch activities and collect
points for prizes
The more points you earn, the bigger your prize could be
APPENDIX
CONVERTING DATA TYPES
Migration Challenges
• Dynamic precision and scale
o NUMBER, VARCHAR2
• Wider range of supported value
o Oracle stores from 4712 while SQL
Server’s DATETIME stores from
01/01/1753 and DATETIME2 stores
from 01/01/0001
o TIMESTAMP has nanosecond
precision while DATETIME2 stores
up to 100 nanoseconds
• Complex data type
o User defined type: Object type,
collections
SSMA Conversion Approach
• Convert to maximum possible
o NUMBER converted to float(53),
which has the maximum precision
from SQL Server floating-point
numbers
o VARCHAR2 converted to
VARCHAR(MAX)
• Project setting
o specify how to handle out of bound
values during data migration
– Error, null, closest supported value
• Raise conversion message when
user defined type is used in
table, view, and PL/SQL program
CONVERTING PROCEDURES AND FUNCTIONS
Migration Challenge
• No big differences between
procedure and function in Oracle
–
–
–
–
error handling
DML statement: update, insert, delete
temporary table access
calling procedures (except extended
procedures)
• Parameter
o Support IN, OUT and IN OUT
parameters
o Scale and precision not specified
o Parameter overloading
• Procedures don’t return result sets
o Use cursors, records and collection as
output parameter
• Autonomous Transaction
SSMA Conversion Approach
• Functions converted to function
and stored procedure when
containing operations
forbidden in functions are
needed
– such procedures have $IMPL suffix
• Extended stored procedure to
call procedure within function
and emulate autonomous
transaction
– master..xp_ora2ms_exec2
CONVERTING ORACLE PACKAGES
Migration Challenge
• Oracle specific implementation to
logically group schema objects
• Compare to SQL Server’s Schema:
• No concept of global package
objects
• Variables and constants
• No concepts of private/public
objects
• Private functions, procedures,
types
• No concept of package state
• E.g. invalid because of
compilation errors
• Module nesting
• Definition of procedures/functions
• Inside other modules
SSMA Conversion Approach
• Convert to procedure and function
with the following naming
convention
• dbo.PACKAGENAME$MODULENAME
• Emulate package variable by storing
values in a central table
• Inline substitution for module
nesting
CONVERTING ORACLE SEQUENCES
Migration Challenge
• Generate number sequence –
not bound to a table
• NEXTVAL method to generate
next value of a sequence
• CURRVAL method to retrieve
current value of the sequence
(bound to current session
scope)
SSMA Conversion Approach
• One table per sequence
• Uses IDENTITY
• Get values through
procedures/functions
• Maintenance
• Additional procedures to
drop/create
• Limitation
• Min/max values are not enforced
• Functions are slower
• Use extended stored procedure to exec
procedure
• Some options not available
• NOCYCLE, NOCACHE, NOORDER
CONVERTING ORACLE TRIGGERS
Migration Challenge
• FOR EACH ROW trigger
• The most common Oracle trigger
which fires for each row of the
source statement.
• SQL Server only supports statement
level trigger
• Before trigger
• Possible to modify the actual field
values that will be stored in the
table, or even cancel the execution
• Allow multiple trigger for each
events (INSERT or UPDATE)
• SQL Server only supports one
trigger per event
SSMA Conversion Approach
• Row-level triggers are emulated
with a cursor loop and generate
ROWID for table with trigger.
• BEFORE triggers are converted
to INSTEAD OF trigger
• Incorporate triggering statement
into the trigger body
• Cursor loop to handle affected
multiple rows
• Logic from all BEFORE triggers
on that table into a single target
trigger.
SSMA 5.0 SYBASE MIGRATION ENHANCEMENTS
• Support for migration to SQL Azure.
• Extended data access connectivity to Sybase ASE ADO.NET and ASE ODBC
providers.
• Support for conversion of case sensitive Sybase database to case sensitive
SQL Server.
• Extended support for conversion of Non-ANSI joins for DELETE and
UPDATE statements.
• Removed dependency on separate SYSDB database on target SQL Server.
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