Database Migration Or The Act Of Moving Computer Science Essay

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DB2s cost model, a migration consists of two parts. First is a direct translation, it migrate code from the source flavor SQL or procedural logic to the target. This translation is a strict syntactic translation of the code. For example, to rewrite for loop because the target system uses a different syntax than the source would be called a translation. The second part is the implementation of workarounds for incompatible instances that have been identified by the analyzer.

A workaround is when the target database does not support certain features used in the source system, and the migration team would need to re-implement part of the code that uses these features and produce new code for the target system that is of equal semantic behavior. For example, calls to a proprietary natural language processing function would require a workaround. The costs of implementing workarounds are stored in the knowledge base. Migration costs vary significantly depending on an extensive list of factors, most notably the experience level of the migration team as well as the tools used in the migration process. For example, some tools can help with the direct translation between different flavors of SQL, e.g. IBM's Migration Toolkit, and the usage of these tools can significantly cut down the cost.

Oracle Database Migration

Pitfalls and Promise An EnterpriseDB White Paper

for DBAs, Application Developers, and Enterprise Architects

July, 2009

Migration tools also don't have human intelligence to decide that simply

converting syntax to syntax may not be the best performing result either.

So, even after the tool converts the code, manual intervention is

necessary. These tools also can't guarantee the converted code will

actually execute the same way as the original code and thus potentially

return incorrect results!

In addition, these migration tools typically focus on the server / database

side and completely ignore the application and any embedded SQL or

calls to stored functions. This becomes the customer's responsibility to

analyze and manually modify the application logic.

Data Migration

Concepts & Challenges-

By Gershon Pick March 2001

"Data migration solutions extract data from a source system, correct errors, reformat, restructure and load the data into a replacement target system".

Data migration is not a job to be taken casually. The data is an immensely valuable asset, built up over years of operations. The whole replacement project relies on successful migration. If the migration project runs into problems, the future of your company may be at stake.

Data Migration is a field that is often overlooked as a simple step between retiring an existing platform and bringing to life a new one.

The actual task of data migration is a complex one requiring experience and a detailed understanding of the steps to be taken, both in terms of business process and technical implementation. This includes a clear delineation of responsibility between IT and business, since far too often the job of manipulating data is relegated to IT, well outside of their core competency. Enabling the migration requires a team experienced in abstracting the technical details such that the business team can implement their rules for migration without ever writing a single line of code, at ask for IT.

Data migration requires human intervention. From planning and change control through the data movement and server or application restart process, there are several levels of staff labor and effort.

This section highlights the often tedious methods of planning, copy, move and verification tasks that are required to be completed by the IT staff and/or external consulting resources.

"Complete the change without anybody in the business realizing that it has happened"

- Rob Dagley, CTO, Global Technology Services, IBM

There are many challenges associated with data migration. First, the amount of data to be migrated is increasing as quickly as storage capacity grows. Second, data migration is problematic for most users.

As storage capacity continues to grow exponentially, it's important to reevaluate the advantages and costs of data migration tools.

Migrating from one database to another is often a high-risk, expensive, and time-consuming process.

Migrating from one database platform can be difficult and time consuming due to differences in standards between vendors.

Data migration is the process of transferring data between storage types, formats, or computer systems. Data migration is usually performed programmatically to achieve an automated migration, freeing up human resources from tedious tasks. It is required when organizations or individuals change computer systems or upgrade to new systems, or when systems merge (such as when the organizations that use them undergo a merger or takeover). (Wiki 20/03/2013)

1 INTRODUCTION

General Introduction

An independent software vendor (ISV) is an individual or business that builds, develops and sells consumer or enterprise software. Although ISV-provided software is consumed by end users, it remains the property of the vendor. ISVs often specialize in building applications for a specific niche or business vertical, such as financial, marketing and educational software.

In short under independent software vendor (ISV), company is making, selling or acquiring software. As a part of IBM's strategic business portfolio improvement, this industry giant keep on acquiring new products like OpenPages, i2, Sterling commerce, UNICA Campaign and PSS Atlas etc. Such application products typically rely on Relational Database Management System (RDBMS) products as their backend data server.

IBM DB2 is a relational model database server developed by IBM. There are three main products in the DB2 family-

DB2 for LUW (Linux, Unix, and Windows),

DB2 for z/OS (mainframe),

DB2 for iSeries (formerly OS/400).

DB2 UDB is a database leader in several technologies, and offers true multi-platform support and scalability. The same database is able to mix workloads on a single server. The DB2 UDB design handles workloads from high-volume online transaction processing (OLTP) to complex multi-user queries while maintaining excellent performance. DB2 UDB is a true cross-platform relational database management system (RDBMS), running on a wide variety of systems including Windows, Solaris, HP-UX, AIX®, and Linux. IBM is perusing various projects to integrate their internal ISV products with DB2. There are six reason to migration database performance, cost saving, usability, scalability, reliability and efficiency from source to IBM DB2

Recently IBM owned a software company Tealeaf which is a Customer Experience Management (CEM) company. Tealeaf used Microsoft SQL Server database. So, Enable IBM's internal Independent Software Vendor (ISV) products on DB2.

Data migration is a subset of the data integration market. Data Migration is the process of transferring data from one system to another while changing the storage, database or application. Typically data migration occurs during an upgrade of existing hardware or transfer to a completely new system. Examples include: migration to or from hardware platform; upgrading a database or migrating to new software; or company-mergers when the parallel systems in the two companies need to be merged into one. There are three main options to accomplish data migration:

Merge the systems from the two companies into a brand new one

Migrate one of the systems to the other one.

Leave the systems as they are but create a common view on top of them - a data warehouse.

Data migration is a key element to consider when adopting any new system, either through purchase or new development. The process of translating data from one format to another is a migration.

Data migration is necessary when an organization decides to use a new computing systems or database management system that is incompatible with the current system.

Data migration is the process of creating a copy of data from one platform to another without disrupting the running applications. Enablement means converting or adjusting the application as per the need of database. Integration is nothing but the combination of both data migration and enablement. Tealeaf company software is having Microsoft SQL Server database which is integrated into IBM DB2. In integration the database is move from MS SQL Server to IBM DB2 server (Database Migration) and according to it there may be changes in application (Enablement).

Figure 1.1: Typical Migration Architecture

Figure 1.1 shows typical Database migration architecture which contains a source database is migrated into target database. In this project source database is Microsoft SQL Server migrated to target database as an IBM DB2 (as shown in Figure 1.4). The migration can be done by using different tools such as a Database Migration Toolkit which is vendor dependent. Tool convert database scripts, tables, stored procedure, triggers, functions and many objects from source to target database. The migration tool is migrate not only database objects but also data.

The following Figure 1.2 show actual working of Internal ISV - DB2 Integration team.

The integration team works on

Assessment

Database schema migration

Resolve issues / Answer queries.

ISV team work on other part such as unit test, QA coverage, performance test and installation.

Figure 1.2: Internal ISV- DB2 Integration / Enablement steps.

Working of Integration team

Assessment

The assessment begins with collecting information about both the source and target environments. Assessment is evaluation or estimation of the nature, quality, or ability of someone or something. Assessment mean calculating or evaluating time and cost require for migration. It can be evaluated by using following points:-

Accessing the environments

In accessing the environments first gather all the information about application and source database as well as target database and then list different software/drivers require to connect to the databases. So this steps gives the cost and time require to access the environments.

Tools

Different types of tools present in the market for assessment purpose which is vendor dependent. Tools carried out specific task and on that basis calculate the assessment. IBM uses tools for assessment purpose know as Migration Evaluation and Enablement Tool (MEET). It is used for automatically evaluation purpose which gives information about how much database objects is directly migrated (compatible objects) and the objects which is not directly migrated ( incompatible objects) .

Database schema Migration

Figure 1.3: Database Migration.

Database migration is rather straight forward, assuming the database is used just as storage. It "only" requires moving the data from one database to another. However, even this may be a difficult task. The main issues one may encounter include:

Unmatched data types (number, date, sub-records)

Different character sets (encoding)

Different data types can be handled easily by approximating the closest type from the target database to maintain data integrity. If a source database supports complex data formats (e.g. sub-record), but the target database does not, amending the applications using the database is necessary. Similarly, if the source database supports different encoding in each column for a particular table but the target database does not, the applications using the database need to be thoroughly reviewed.

When a database is used not just as data storage, but also to represent business logic in the form of stored procedures and triggers, close attention must be paid when performing a feasibility study of the migration to target database. Again, if the target database does not support some of the features, changes may need to be implemented by applications or by middleware software.

Data migration is the process of making an exact copy of an organization's current data from one device to another device, preferably without disrupting or disabling active applications and then redirecting all input/output (I/O) activity to the new device.

IBM has series of tools to carried out this migration,

IBM Data Movement Tool (IDMT)

IBM Migration Toolkit (MTK)

By using this tools migration is done for compatible objects and remaining incompatible objects is migrated by using DB2 Command Line- Processor (CLP) i.e. by manually. Migrated database is sent to ISV team for carried out next steps. Team accomplishes the unit test, QA coverage and performance test. During this process if they get any issues / queries regarding to database migration is send back to DB2 migration team.

Resolve issues / Answer queries

Integration /Enablement team will solve the issues given by ISV team. After solving the issues there is again different types of test is carried out to check the working of application.

Migration Process flow

Figure 1.5 shows the flow of migration process. It contains following different process

Access the Migration Project: - The process is come under the assessment part of an integration team.

Migrate the Schema & Data: - Migration of MS SQL Server database schema and data into IBM DB2 by using different tools of IBM.

Migrate the Business Logic: - As per need of database make changes into the Business logic and migrate it. In SQL server database had several schemas which are migrating in DB2 by making three schemas.

Test the converted database: - The migrated database must be test to check whether it is working properly or not.

Migrate Application: - After successful database migration, application migration should be done.

Test, integrate & deploy: - Integrate the migrated application with target database and then carried out test and deployment.

Optimize the performance: - IBM having different tools used to optimize the performance.

Figure 1.4: Migration process flow.

DB2 Integration Details Process Working

Figure 1.5: DB2 Integration Details Process Working.

Integration can be extremely difficult for a numerous reasons. First, databases often store the same data in different ways, sometimes drastically so. Mapping between these differences can be time consuming, especially when ensuring that the information transfers back and forth correctly. Secondly, data is often generated by third-party programs and then inserted into the database. When you integrate systems, you need to be sure you are not breaking those third-party systems' communication processes. Lastly, databases are often stored on different computers on different networks so keeping the data secure can be tricky.

Data Integration Areas

Data integration is a term covering several distinct sub-areas such as:

Data warehousing

Data migration

Data integration involves combining data from several disparate sources, which are stored using various technologies and provide a unified view of the data. Data integration becomes increasingly important in cases of merging systems of two companies or consolidating applications within one company to provide a unified view of the company's data assets. The later initiative is often called a data warehouse.

Here the project is working on 2nd part where data migration is main thing.

Server. You can also use the

IBM DB2 Migration Toolkit (MTK) to retrieve structural and object information

from a SQL Server database.

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