Solution for

database transformation / migration

1. IntroductionDatabases are the long-term memory ofenterprises: their content must be ported from onetechnology generation to the next one. Currently,the database market is « hot » regardinginnovations: NoSql, Big Data / Hadoop, key-datadatabases, in-memory databases, cloud databases,etc. are becoming de facto standards after a periodof stability around the canonical relationaldatabase model materialized by IBM Db2, OracleDatabase, Microsoft Sql Server as dominantcommercial players.

The CIO must carry this « enterprise memory »from current standard to next one whilemaximizing smoothness and invisibility when hemigrates those business data to a new platform. Asafe and riskless approach is key in order toguarantee business continuity and stable qualityof services for the mission-critical applications.

This task is more complex than it seems becauseeach database, supposedly respecting the SQLstandard, extends it with additional proprietaryservices often used by applications. Moreover, theSQL standard is not sufficiently precise or is evenincomplete on some specification aspects: itleaves room for incompatibilities betweenimplementation in sql requests, data formats, etc.

To satisfy this need for database transformation,Eranea proposes a solution which is:

• Comprehensive: it covers transformationof structures (tables, indexes) as well astransformation of data but also real-timeadaptation of sql access requests to avoidany impact on application source code.

• Incremental: data migration can happen inconsecutive steps: only one fragment ofthe whole database in migrated at a time.Transactional integrity mechanisms likethe X/Open XA protocol are used toguarantee, during migration, full integrityof data splitted between old and newdatabase management system.

• Transparent: data access requests areadapted to the syntax of the new databaseon the fly to avoid any requested changeon application source code during themigration. Eranea's transformation enginewill intercept sql requests (select, insert,update, delete,etc.) and responses in realtime and adapt their format to makeapplication source code compatible withthe new syntax of the new databasemanager and make new answers fullyequivalent to old answers in their structureand content. So, no change at all isrequired on application source code.

• Efficient: the transformation enginesupplied by Eranea concentrates, in oneplace, all changes made to sql requests anddata results. The migration is invisible toapplication developers who can remainfocused on the implementation of newbusiness requirements.

• Riskless: the transparency of the switch tothe new system and the incrementality ofthis transformation eliminate all risks ofthe project in order to guarantee businesscontinuity.

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2. ObjectivesThe CIO pursues various objectives when hetakes the decision to migrate databases:

• Cost optimization: Open Source databaseslike PostgreSQL have vastly progressed inthe last years. The last 2015 « MagicQuadrant » from Gartner Group positionsthose OSS databases on par - regardingfunctions and performances - withproprietary and commercial systems. But,the cost advantage for OSS databasesremains unbeatable: their license is freeand their cost may be limited to some veryaffordable support contract.

source: Gartner Group 2015

• Rationalization: new application after newapplication, diversity, and evenincoherence has emerged in the IT systemof the enterprise through the use ofvarious database technologies. The CIOmust reorganize this landscape throughunification on an homogeneous platformin order to put all data under control withmaximum efficiency, in a period where thevolume of this data explodes.

• Flexibility / Agility: the innovation in thearea of database technology is currently« boiling ». Optimal management andleverage of corporate data through newtechnologies (Big Data / Hadoop, etc.) isessential to maximize businesscompetitive advantage. So, data

transformation toward those newplatforms must be fully automated, simpleand efficient.

3. ReferencesEranea's technology already allowed multipledatabase migrations, especially through large-scale projects aimed at transforming mainframe(Cobol) or mission critical applications towardJava/web for cloud computing, core business ofour company.

To mention some among most recent ones:

• Transformation from DB2 to PostgreSQLfor database of the core banking of a largeinternational private bank: 14'000relational tables representing 5 terabytesof data.

• Transformation from DB2 to Sql Serverfor an insurance company: 1'500 tablestotaling 500 gigabytes of relational data.Heavy use of triggers and referentialintegrity.

Hence, Eranea's technology is proven and willallow you to move your data toward a newplatform through a safe and efficient project.

4. MethodologyEranea applies to data transformation the sametechniques that we practice daily in global systemtransformation toward cloud computing:

• Automation: the various steps (example:database unload / reload) of a databasemigration are, by essence, repeatedmultiple times during the course of large-scale migration project. Eranea uses fullyautomated tools to analyze and transformddl (creation of structures), to unload /reload data, to analyze and transform dml(data access). This way, those steps can berepeated as often and as much as needed

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without incurring a cost explosion inhuman resources and duration. Thedatabase structure and content as well asthe application can then continue to evolvewithout constraint while the migrationproject is progressing.

• Incrementality:

◦ The techniques implemented in oursolution allow the database to bemigrated in chunks toward the newtarget: data is partitioned intoindependent subsets throughautomated full-scale activity analysis.Those subsets can then be migratedone after the other. Data integrity isensured via XA from X/Open.

◦ The switch toward new target databaseis initially invisible for the applicationuntil full migration is achieved: thereal-time sql transformation enginewill intercept sql requests, analyze andreformulate them to reachcompatibility with new system whilepreserving strict iso-functionality inthe returned results (data formats,return codes, etc.) with previousdatabase system. So, developers won'tsuffer any impact during migration.Only after migration project can theystart implementing, in their referencesource code, the changes done « underthe hood » by the transformationengine in order to get rid of it.

• Productivity: the entire transformationhappens in a manner totally invisible todevelopers and without any freeze ofapplication maintenance for end-users.The maximum productivity of allstakeholders is then fully maintained.

• Safety: fine-grained incrementality andfull transparency of the solution, coupledto an objective and quantified testing, also

supplied by Eranea, delivers a fullyriskless transformation.

• Transparency: multiple reports producedby analysis tools deliver very clear andprecise global information as well as fulldetails on the level of changes executed bythe various components on structures, dataas well as on access requests. It allows, inparticular, the customer to evaluate earlythe amount of retro-fitting needed toremove transformation engine after theproject.

5. TechnologyEranea's solution is mostly composed offollowing services:

• A tool to analyze and transform thecontainers (ddl: tables, indexes,referential integrity constraints, triggers,authorizations, etc.): it guarantees that thedefinition of those containers is adaptedto match the requirement of the targetsystem with a minimum level of changeswhen compared to their initial structure.

• A tool to unload / reload data: fullyparallel (= highly multi-threaded), itallows to handle very large sets of datawith top-level performances. Duringreloading, the tool will automaticallyadapt data (encoding, structure, etc.) to aformat compatible with new databasesystem.

• The request transformation engine: basedon various interception techniquesdepending on technical context, theengine will capture the text of the originalsql request as produced by theapplication. Then, the integrated sqlanalyzer will parse it and regenerate it ina new format compatible with the targetsystem. When answers are returned, theengine will also, as needed, adapt the

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format of those answers (data, responsecodes) to guarantee full transparency forthe application. This engine can alsooperate in passive mode where it onlycaptures requests and answers to analyzeto details and where it produces metrics(response time, throughput, etc.)regarding database activity.

Those cornerstones of our technology are alsoequipped with detailed reporting capabilities inorder to obtain very granular details on alltransformations performed to reach compatibitywith new target.

Finally, all the components work in a fullyautomated mode in order to be executedrepeatedly as needed at no additional HR costduring the project and to leverage best DevOpspractices.

6. Project organizationA standard project will usually incur thefollowing steps:

1. Analysis and execution of structure(tables, indexes, etc.) transformation tomatch constraints of new target (done in atest environment).

2. Analysis and execution of data unload /reload (done in a test environment).

3. In parallel with steps above, installationand activation of interception engine inpassive mode on production systems tomeasure and analyze database activity aswell as to evaluate all requiredtransformations of sql requests.

4. Execution of functional test scenarios(transactional and batch) as supplied bycustomer. Quantification of their relevancethrough automated analysis of source codecoverage. Strict and automatic validationof iso-functionality, request per request,through comparison of responses obtained

by the application and of changes (directlythrough application or indirectly viareferential integrity or triggers) made ondata in the system for an execution on theold system and an execution on the newsystem.

5. Incremental transformation of productivesystems through incremental migration ofindependent data subsets, eachindependent from each other from a dataintegrity standpoint (ACID properties).During this step, transformation is fullyinvisible to application: no change insource code.

6. Subsequent retro-fitting of needed changesto match new database system constraints:sql requests in application source code areadapted. These adaptations can be donevery quietly and smoothly: as long as thetransformation engine remains in place, hewill transform automatically all sqlrequests not yet changed by developers,who can adapt at their own pace, forexample when they need to work on agiven module for functionalimprovements.

In those projects, Eranea can provide, as needed,additional professional services to train teams tothe new platform and to work as well on thecorresponding evolution of system architecture(high availability, optimal performances, disasterrecovery, etc.) and the evolution of operations(administration, data backup / recovery, etc.).

7. Next stepsYour mission-critical databases have to bemigrated smoothly and safely toward a newsystem in order to optimize, transform the core ITsystems of your enterprise ?

We are available for any additional question thatyou may have or information that you may need.Drop us a mail: contact@eranea.com.

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