What are the questions should ask to the customer about the existing database?

Question

What are the questions should ask to the customer about the existing database?

C.K.Shaiju

SSCarpal Tunnel

Points: 4228
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May 30, 2012 at 4:19 am

#392380

Hi Guys,
I need a help.
Customer requirement is to merge 3 to 5 databases to a single database. Before proceeding to this I required to know the current details (Configuration, Load, version, users.. etc..etc) of the existing databases. What are the questions should I ask to the customer about the databases?
Please provide your questions or provide any good existing links.
Regards,
Shaiju CK
_____________________________________________
One ounce of practice is more important than tonnes of dreams

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MysteryJimbo SSC-Insane Points: 24203 More actions · Answer 1

C.K.Shaiju (5/30/2012)
Hi Guys,
I need a help.
Customer requirement is to merge 3 to 5 databases to a single database. Before proceeding to this I required to know the current details (Configuration, Load, version, users.. etc..etc) of the existing databases. What are the questions should I ask to the customer about the databases?
Please provide your questions or provide any good existing links.
Regards,
Shaiju CK

Things I can think of

Collation

Growth

Archive processes

Related SQL jobs

Backup schedules

Reporting requirements (logshipping? replication?)

High availablility

Maha-848518 SSC Enthusiast Points: 142 More actions · Answer 2

Security - ensure the users are merged and required access is given.

Recovery Model - do you want the recovery model to be changed?

Koen Verbeeck SSC Guru Points: 259105 More actions · Answer 3

Maintenance jobs

Related products using those databases, such as SSIS, SSAS and SSRS.

Need an answer? No, you need a question
My blog at https://sqlkover.com.
MCSE Business Intelligence - Microsoft Data Platform MVP

C.K.Shaiju SSCarpal Tunnel Points: 4228 More actions · Answer 4

Thanks friends 🙂

Any more questions?

_____________________________________________
One ounce of practice is more important than tonnes of dreams

Koen Verbeeck SSC Guru Points: 259105 More actions · Answer 5

And of course what the databases are used for:

* reporting/analytics (data warehouse)

* OLTP support for an application

* archiving

* ...

Need an answer? No, you need a question
My blog at https://sqlkover.com.
MCSE Business Intelligence - Microsoft Data Platform MVP

Mike Menser Hall of Fame Points: 3679 More actions · Answer 6

Sizes of the databases

Are there existing external connections to the data etc.

ScottPletcher SSC Guru Points: 101097 More actions · Answer 7

I would think that object name clashes would be a potential concern. If they occurred, resolving those could theoretically involve a LOT of work.

SQL DBA,SQL Server MVP(07, 08, 09) "It's a dog-eat-dog world, and I'm wearing Milk-Bone underwear." "Norm", on "Cheers". Also from "Cheers", from "Carla": "You need to know 3 things about Tortelli men: Tortelli men draw women like flies; Tortelli men treat women like flies; Tortelli men's brains are in their flies".

David Webb-CDS SSCoach Points: 17398 More actions · Answer 8

Merge as in "Structures are the same and the data needs to be combined" or "structures are different and objects need to all be in a common database"?

If the former, you'll need to know the data model and the way the related columns interact (all natural keys, generated ids, any ranges of ids that mean something, any intelligence built into generated keys, etc.). If there is a possible duplication if ids, you'll need a strategy for resolving the conflicts and still keep the related data related.

And then again, I might be wrong ...
David Webb

C.K.Shaiju SSCarpal Tunnel Points: 4228 More actions · Answer 9

Mike Menser (5/30/2012)
Are there existing external connections to the data etc.

Hi Mike, I dint understand this line.

ScottPletcher (5/30/2012)
I would think that object name clashes would be a potential concern. If they occurred, resolving those could theoretically involve a LOT of work.

Hi ScottPletcher, Yes object name clashes are there. Agreed. it is a lot of work :(.

David Webb-200187 (5/30/2012)
Merge as in "Structures are the same and the data needs to be combined" or "structures are different and objects need to all be in a common database"?
If the former, you'll need to know the data model and the way the related columns interact (all natural keys, generated ids, any ranges of ids that mean something, any intelligence built into generated keys, etc.). If there is a possible duplication if ids, you'll need a strategy for resolving the conflicts and still keep the related data related.

Hi David, Structures are partially same and need to all be in a common database. For the existing databases, there is no pk fk relations have been created (What a joke) and struggling to find out the relations between tables. Sure, will take care of that duplication issue.

Thanks guys 🙂

_____________________________________________
One ounce of practice is more important than tonnes of dreams

MysteryJimbo SSC-Insane Points: 24203 More actions · Answer 10

C.K.Shaiju (6/1/2012)
ScottPletcher (5/30/2012)
I would think that object name clashes would be a potential concern. If they occurred, resolving those could theoretically involve a LOT of work.
Hi ScottPletcher, Yes object name clashes are there. Agreed. it is a lot of work :(.

Its possible to work around this by using schema's to separate objects. This would require fewer changes in any code. I'd probably consider different filegroups for each "database" upon merge so you could have the ability to backup individually.

What is the justification for this business requirement as I would question it myself? If the databases are on the same server they can cross communicate without impact anyway. 5 databases seems like a minimal administrative overhead.

MysteryJimbo SSC-Insane Points: 24203 More actions · Answer 11

Another idea I've thought of is you could use a logical database (views) merging the physical databases. This would work as a testbed as well if you pursued the idea of merging. You could stage the merges one by one.

Jeff Moden SSC Guru Points: 1004329 More actions · Answer 12

C.K.Shaiju (5/30/2012)
Thanks friends 🙂
Any more questions?

Yes... there are two that are very important that I've not seen, yet, that need to be asked of the customer.

1. Why do you want to do this?

2. What are the benefits that you think you'll get by doing this?

--Jeff Moden

RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
First step towards the paradigm shift of writing Set Based code:
________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.

Change is inevitable... Change for the better is not.

Helpful Links:
How to post code problems
How to Post Performance Problems
Create a Tally Function (fnTally)

manus4u Ten Centuries Points: 1238 More actions · Answer 13

Hope u know me ;-)!!

Port no (incase if they aint using the default one).

&

Service Accounts

Eric M Russell SSC Guru Points: 125561 More actions · Answer 14

One question them or perhaps just you would be:

Are we really talking about consolidating databases that currently exist on the same server, or are we talking about consolidating servers?

Why are they wanting to consolidate into one database; what is the goal?

Can you speak directly with the person who chose to make that architectural decision?

"Do not seek to follow in the footsteps of the wise. Instead, seek what they sought." - Matsuo Basho