26

When I first committed to DBA, it was generically named as "Databases". Now that we have the private beta up and running - what questions are allowed in here ?

The site name indicates that the questions allowed are more from an database administration point of view - which would mean most of the questions deemed as "on-topic" during A51 stage might be considered off-topic now ( one of the main reasons why I keep harping on why was it renamed)

In short: Are the questions voted as "on-topic" still hold relevance ? Or will these be closed / migrated to SO ?

Note : When looking at the answers below, you should click on the current vote tally for an answer ( or click here which sorts on a newest answer first basis) -- some are at 1 or 2 because they're new and people haven't voted on them (or people haven't voted as they're not sure or don't care), while others have a number of both + and - minus votes that cancel out.

6
  • 1
    I like to follow the definition on Area51 but in this case we have a change of the target. To avoid problems later we should get new definition here quickly. P.SE teach us that a wrong perception on begin is very hard to change later.
    – Maniero
    Commented Jan 4, 2011 at 13:29
  • 1
    @bigown Agree, setting the precident on what questions are acceptable early on will prevent There are x questions on xyz - why are they not closed? kinda comments(flames?)
    – Sathyajith Bhat
    Commented Jan 4, 2011 at 13:33
  • 2
    So there's actually some way to vote for/against topics for inclusion, it'll be best to just answer w/ one topic that's not too ambiguous ... I'll go add a few.
    – Joe
    Commented Jan 4, 2011 at 14:59
  • okay, there's 9 ... feel free to vote 'em down if you don't think they're relevant, or add some that are at the edges that we need to vote yes/no on to really set the scope.
    – Joe
    Commented Jan 4, 2011 at 15:19
  • @bigown I fear that we're too late already. So many questions have already started to proliferate the wrong topic target. At this point in time, in the middle of private beta where committed individuals should be more targeted in their approach to asking/answering questions, I'm dismayed at the lack of quality and focus in the posted questions.
    – ScottCher
    Commented Jan 4, 2011 at 21:15
  • 3
    @Joe Thanks - that's a good smattering of on and off topic questions. Now we only need to get the current private beta users to read them and start adjusting their questions. I think we should be relatively rutheless in closing off-topic questions while in private beta so we don't get buried in public beta - by then it will be too late to correct the course.
    – ScottCher
    Commented Jan 4, 2011 at 21:18

25 Answers 25

Reset to default
22

Query Tuning

Improving queries from the developer side (using hints, forcing a better style of join for those without hints, etc.)

2
  • 2
    this should be allowed but it's a tricky subject , it in time this will turn into "Please write me a faster query" ( just like on stackoverflow ) when it should be "Why is this query slow and how can i improve it" .
    – poelinca
    Commented Jan 4, 2011 at 15:42
  • I was thinking more of the 'how can I force a sort-merge join in postgresql' ... but you're right, we might need to refine it some more. Either toss it in as separate option, or feel free to edit this one until people have either voted for/against it. (so we don't change the meaning of their vote)
    – Joe
    Commented Jan 4, 2011 at 16:40
19

Data Modeling

How to organize data to be stored within a database.

10
  • So to me this seems like your saying schema concerns. But that to me reeks of either pure SQL (so it would be a SO question) or else a question of programming concepts, so seems to be a matter of P.SE. Can you explain for me how this wouldn't be for either of those two sites? Just so we're clear. ~ Or do you by chance mean "indexes placed on spindle A, data files on spindle B" sort of "organization"?
    – jcolebrand Mod
    Commented Jan 5, 2011 at 2:53
  • 1
    @dracherstern : I don't know what you mean by 'schema concerns' ... (unless maybe you mean in terms of conceptual/logical/physical schemas). Conceptual schemas are likely out of scope, but trying to identify classes and determine how to store it in a database (for an RDBMS, normalizing your tables, etc.). I typically think of the physical schema issues (that goes on which disk) to fall under tuning, but that's just my take on things.
    – Joe
    Commented Jan 5, 2011 at 3:14
  • I think we're in sync. I meant logical schemas, and I figured they would be out of scope. As for how to map a (eg) C# class to a table ... isn't that the realm of SO or did I lose you again? The rest yes.
    – jcolebrand Mod
    Commented Jan 5, 2011 at 3:28
  • @drachenstern : sorry, I meant 'class' as in 'class diagrams' a la UML (ie, ER modeling), not a specific software implementation, which is one of the database-y things that we don't currently have a good place for w/ Server Fault or Stack Overflow.
    – Joe
    Commented Jan 5, 2011 at 5:07
  • Oh, ok. So do we mean like how to translate a UML into the language of the database in particular?
    – jcolebrand Mod
    Commented Jan 5, 2011 at 5:08
  • @drachenstern : there's that, and there's also the bottom-up approach of taking the values to be stored, and coming up with a good class diagram/ER model of how to represent it (and possibly figuring out if it's a better for an RDBMS or some other type of database) ... but that might get into a little much to handle on this type of site.
    – Joe
    Commented Jan 5, 2011 at 5:44
  • Or it might be just what we need. Let's see if anyone else comments.
    – jcolebrand Mod
    Commented Jan 5, 2011 at 5:50
  • 1
    IMHO Data Modelling is not strictly database administration - sure, plenty of DBAs do it, but it doesn't mean it's a "db admin" task. Data modelling (esp. conceptual/logical) is a (very important) part of software design. For this reason, there would be too large an overlap between SO and DBA if data modelling questions were encouraged here.
    – Jeffrey Kemp
    Commented Jan 5, 2011 at 15:11
  • @Jeffrey : Robert has said the name isn't fixed in stone ... so consider where a good boundry would be, not what is/isn't the role of a DBA. And besides, data modeling fits under SO? Are you going to have the same experts in Information Architecture hanging around SO?
    – Joe
    Commented Jan 5, 2011 at 15:20
  • I have a question about designing an SQL database schema. I have several tables and relations between them and I would like to optimize them. Is creating a new question about it a valid use under the data-modeling tag?
    – Alator
    Commented Apr 13, 2021 at 12:15
18

Database Tuning

Tuning from the server side (indexes, memory allocation, etc.)

17

Database Administration

To include setup/install, backups, restores, troubleshooting problems.

3
  • 1
    possibly, but this might overlap with Server Fault a bit
    – Jeff Atwood
    Commented Jan 4, 2011 at 17:31
  • 3
    we are going to have to live with some overlap no matter what. It is hard to eliminate all overlap when we have Server Fault, SO, Programmers, SuperUser (which does have some access and VBA type programming questions). So far the overlap kind of works though because you can ask in a different place in order to get a "Flavored" answer. For instance, a DBA's expert answer about restores may be more specific or have a couple things to watch out for DB wise then a Server Fault expert might have.
    – Beth Lang
    Commented Jan 4, 2011 at 17:52
  • 1
    I think that there is a range where the DBA has to step in, with knowledge specific to the DB platform. I think this is appropriate within limits. I agree we need to try to establish those limits, but even once again we run into I'll know it when I see it :(
    – jcolebrand Mod
    Commented Jan 5, 2011 at 3:06
17

Data Warehousing

Data warehousing and OLAP questions are... an extremely different breed to most questions so far, and tend to involve quite a lot of programming and hardware expertise.

16

Nonrelational database systems.

I use GAE and quite a lot of ideas translate over from RDBMSes, but the more "nonrelational" you get, you get fuzzy on the whole Database thing.

Bad Example: Questions on XML used as a database Good Example: Questions on object DMBses

1
  • There are 'XML databases' ... but I'm a fan of hierarchical databases (eg, LDAP) for storing registry information ... I never could understand why people liked sparsely populated RDBMSes.
    – Joe
    Commented Jan 7, 2011 at 16:50
15

Possible Database Bugs

I'm doing ..., but getting unexpected results ... Is this a bug?

1
14

Questions about database terminology / concepts

Eg:

  • What's the difference between a LEFT OUTER JOIN and a RIGHT OUTER JOIN
  • What is the difference between a clustered and non-clustered index, and when should I use each?
  • What are database triggers? What are the advantages/disadvantages and when is the right time to use them?
  • questions about fundamental differences between RDBMS vs. hierarchical vs. network vs. key/value stores.

(first three from the area51 definition)

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  • 2
    I think most of these are valid, so I'm upvoting it, but I disagree with the first one (currently what's the diff between joins)
    – BlackICE
    Commented Jan 4, 2011 at 19:38
  • Agreed - all but the first bullet seem appropriate. There's already a question about the difference between INNER and OUTER JOIN - something so easily searched on the web that I made this: lmgtfy.com/?q=difference+between+INNER+and+OUTER+JOIN
    – ScottCher
    Commented Jan 4, 2011 at 21:03
  • I see "joins" and "triggers" as the same. The others probably are different enough. But I think these are acceptable.
    – jcolebrand Mod
    Commented Jan 5, 2011 at 3:07
  • 1
    @ScottCher : yes, it's possible to find lots of responses to the question that someone still might not understand, which is why it likely gets asked & answered so many times.
    – Joe
    Commented Jan 5, 2011 at 19:23
  • Why would the first one (Difference between LEFT and RIGHT on join) be a poor choice for this site?
    – corsiKa
    Commented May 31, 2011 at 0:45
14

I don't think this is already considered in the other list of suggested answers.

Questions about ACIDity. I'm still not sure if this is for here or CompSciTheory or SO or P.SE so I'm tossing it to the community.

6
  • yay, an option I can actually vote for, as I'm not allowed to vote on my own submissions!
    – Joe
    Commented Jan 5, 2011 at 5:08
  • lol, you're welcome Joe ;)
    – jcolebrand Mod
    Commented Jan 5, 2011 at 5:32
  • 3
    This should be decided case-by-case. When a question affects the dba job, it's appropriate here, when it's mainly a programming or academic problem, it's off-topic.
    – Maniero
    Commented Jan 5, 2011 at 16:34
  • @Bigown ~ Indeed. That's what I'm thinking, but as I see this being the precursor to a FAQ I wanted to get it in early.
    – jcolebrand Mod
    Commented Jan 7, 2011 at 21:26
  • I agree "case-by-case". I believe it would be on-topic if someone needed to know how they were implemented in a product (eg Oracle vs SQl Server) or how it might impact a high-concurrency process.
    – Gary
    Commented Jan 10, 2011 at 5:35
  • That's sort of what I was thinking there @Gary when I posted this. I also wanted to point out that we need to differentiate and specify the types of these questions that are permitted. Some ACID questions will inevitably be CSTheory. etc.
    – jcolebrand Mod
    Commented Jan 10, 2011 at 5:38
13

Database Features / Comparisons

Either questions of what databases have what features, or how to accomplish things from one database in another one, or even helping to select a good database for a given task.

13

Database-related Software

Questions about software related to database backups, replication, administrative GUIs, etc.

(Should this also include things like client software, eg, perl DBI ?)

1
  • 1
    If not here, then SF. Is there a line between this and SF?
    – jcolebrand Mod
    Commented Jan 5, 2011 at 3:03
12

Theory of Databases

Questions on relational algebra and original database research that never touches questions about code.

2
  • Wouldn't want to see theoretical questions, but questions like when would I use a Document database rather than relational should be allowed.
    – Gary
    Commented Jan 10, 2011 at 5:41
  • 1
    @Gary Why aren't theoretical questions OK. Can you make 2 answers with a subset that you do and don't want to see?
    – Brian Ballsun-Stanton
    Commented Jan 10, 2011 at 6:24
11

Database Queries

Questions of the form 'if my tables look like (x), how can I extract (y)' ?

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  • 9
    only if they're ninja-level extremely complicated "for experts" type queries IMO
    – Jeff Atwood
    Commented Jan 4, 2011 at 17:31
  • 6
    Why not simpler ones? I guess what I'm asking is are we still encouraging SQL programming to be only on SO and if so why? The problem I see with doing that is you force someone who is really a DB only person to be on two sites. Also, who will be the ninja judge? Should we just post something on either dba.se or SO and then rely on migration if people vote that you have it in the wrong place? It seems nicer to the user to give them a cut and dry answer of SQL/DB on one site, non-DB on the other or DB only here and SQL/non-DB on SO.
    – Beth Lang
    Commented Jan 4, 2011 at 17:46
  • 2
    I'm with Jeff here, SO is the go-to site for all things programming related (except subjective stuff, where you go to programmers.SE). Based on the of the site, I'm going more with DBA stuff, which IMO doesn't really include querying the database much.
    – BlackICE
    Commented Jan 4, 2011 at 19:36
  • 1
    @Jeff : I can hope for things like anything Quassnoi answers ... see his blog at Explain Extended, but if people ask stupidly simple questions, they'll get downvoted, just as if someone asked a stupid perl/C/python question on Stack Overflow. You know the ones I'm talking about
    – Joe
    Commented Jan 5, 2011 at 1:36
  • 1
    Basically I agree with Jeff. This is a pro site, decision should be based on specific content. It's too early but I post some questions relatively simple and I got wrong or bad answers. Worse, the wrong answer got some up-votes.
    – Maniero
    Commented Jan 5, 2011 at 16:49
9

Dedicated Database Server Setups

Questions about hardware requirements (memory, disk, etc) when setting up dedicated database servers

5
  • meta.dba.stackexchange.com/questions/11/… handles that
    – Sathyajith Bhat
    Commented Jan 6, 2011 at 16:52
  • @Sathya : they don't have to be mutually exclusive (although, it helps to keep the list from getting too long) ... sometimes it's good to break out a narrow topic if you don't agree with the way the votes are going on it, to see if people are voting on the broader grouping and accepting it by default, or really don't agree on an edge case. So for this one, I can't make up my mind -- does it belong here, or on ServerFault as a sysadmin type question.
    – Joe
    Commented Jan 6, 2011 at 19:16
  • 1
    @Joe that's kind of what i was thinking. I posted this one because the hardware aspects seem to belong on SF, so didn't think it fit with the other group. However, the more I think about it, it's going to be a DBA who is more familiar with hardware requirements of a properly tuned database server.
    – Derek Downey
    Commented Jan 6, 2011 at 20:00
  • Seems like this belongs more to ServerFault.
    – Beth Lang
    Commented Jan 9, 2011 at 20:46
  • 1
    I was thinking ... in some ways, this falls under 'database tuning' ... putting the database on the right hardware to get the best performance.
    – Joe
    Commented Jan 10, 2011 at 7:41
9

Subset of: Database-related Software

Third-party database tools

Are questions on TOAD ok? Are questions on one of the tools mentioned Tool to generate large datasets of test data here OK?

7

How to use the Documentation

Oracle docs are horrible in their complexity and there may be many questions that could be answered by reading them if the querent knew what to look for. How "meta" in this regard can we go?

3
  • Also, Possibly subjective in nature
    – Sathyajith Bhat
    Commented Jan 8, 2011 at 5:29
  • Better off asking for alternative information sources for a product (which should be a valid question)
    – Gary
    Commented Jan 10, 2011 at 5:43
  • @Sathya yeah, but the oracle docs do need a helping hand of "What's going on?"
    – Brian Ballsun-Stanton
    Commented Jan 10, 2011 at 5:45
5

Programming in Databases

Writing triggers, stored procedures and the like in PL/SQL, T-SQL, plperl, etc.

7
  • 1
    I think this falls in the same place as Database Queries, these types of questions should be on SO.
    – BlackICE
    Commented Jan 4, 2011 at 19:37
  • 1
    Since the name was changed to DBA, I agree that this is not appropriate. I'm bummed that the name was changed between having committed and the private beta but I'm adjusting. I don't think the majority of others are. I mean really - what's the difference between an INNER and OUTER JOIN?!? Really?
    – ScottCher
    Commented Jan 4, 2011 at 21:00
  • right now it's called database administrators ... Robert has already said that could change -- see his response to my comment. So focus on what should be included in a database-y SE site, not what belongs on 'dba.stackexchange'
    – Joe
    Commented Jan 4, 2011 at 22:00
  • 4
    Then in that case I think that triggers are the domain of DBA since most coders don't deal with such things
    – jcolebrand Mod
    Commented Jan 5, 2011 at 3:19
  • @drachenstern : if it's a case of 'most people haven't had to deal with it' (and it's DB-related), does coding that require cursors count, too?
    – Joe
    Commented Jan 5, 2011 at 3:27
  • 1
    Actually ... I've seen coders screw up cursors, because they don't understand them. I might say yes to cursors, but I know my bent as I come onto the site.
    – jcolebrand Mod
    Commented Jan 5, 2011 at 3:30
  • 2
    There is some sort of Meta-Programming, i.e. stored procedures to maintain database, which uses the procedural features of databases stored procedures, functions etc which ought be treated here. The difference is that these scripts are doing. I haven't yet a suitable name. Definitely I want avoid to call it programming.
    – bernd_k
    Commented Jan 5, 2011 at 21:41
5

Theories of Data

(Integrating my question about "Can I ask about the philosophy of data"). The ontological underpinnings of databases are sometimes really important. But are they on topic for this site?

2
5

Writing Database Software

I don't mean using a database ... I mean questions by the developers of databases, eg, how to implement new features whenever the next SQL standard is released.

4
  • To which DBMS are you referring? In context with the main players like SQL-Server and Oracle for me it seems to be off topic, but in context of OpenSorce systems I guess it's boarderline
    – bernd_k
    Commented Jan 8, 2011 at 15:32
  • @bernd_k : I doubt we'd get MS or Oracle asking ... even MySQL and PostgreSQL likely have their own forums ... I was thinking it'd most likely be people writing small custom databases or the like, but I could see people asking question about where to get info on how to extend/modify mysql or postgresql.
    – Joe
    Commented Jan 8, 2011 at 16:02
  • 1
    +1 It is a good idea to encourage developers to ask DBAs and not to let them invent wheels by their own.
    – bernd_k
    Commented Jan 8, 2011 at 16:20
  • I think it is off-topic. It is mostly going to be a programming issue, and how a specific product 'does' something could well be covered by intellectual property rights anyway.
    – Gary
    Commented Jan 10, 2011 at 5:38
4

Questions about standards & interoperability

Not necessarily SQL as a standard, but different standard schemas / codings / formats / etc used in different industries, either as they relate to storage within a database or extraction from one.

2

Instead of Manual Lookups

Canonical example: How does the Oracle DUAL table work?

We're going to get a lot of those: "I don't know what question to ask of the manual, so I'll ask a general one here."

We need a rule for these.

1
2

Database Recommendations

"What model should I use?" "What DBMS should I use?"

We need a level of "you need to tell us this much before we can make a recommendation" or forbid these vague questions entirely.

1
  • 1
    Only if the answer back isn't necessarily an RDBMS ... too many people use 'em without understanding when other types of databases are a better alternative.
    – Joe
    Commented Jan 10, 2011 at 7:38
0

Interview Questions

I am specifically thinking of interview questions that can't be answered from a single piece of documentation such as:

The database crashed and you lost a drive containing one of your control files and another drive containing an entire redo log group. You have a level 0 backup from yesterday morning, a differential backup from yesterday evening, and a cumulative backup from this morning. In addition three days of redo logs are on disk. You backed up the control file to trace just an hour before the crash. How do you recover the database?

-4

Trick Questions

Is it OK to ask a question knowing that due to the specific wording of the question or a specific trick that an answer other than the expected one is correct?

3
  • No, if you want to ask this goto CodeGolf.SE or the like. ;)
    – jcolebrand Mod
    Commented Apr 21, 2011 at 18:47
  • 1
    That was my opinion as well, but I wanted to see it listed specifically.
    – Leigh Riffel
    Commented Apr 21, 2011 at 19:35
  • Agreed. Good to go ahead and get it out there.
    – jcolebrand Mod
    Commented Apr 21, 2011 at 19:57
-12

Programming that uses databases

Writing software that uses a database for its data storage. (just general 'usage' of a database: select / insert / update, etc.)

11
  • 1
    For sure an SE topic.
    – Beth Lang
    Commented Jan 4, 2011 at 17:52
  • SE == Stack Exchange, or do you mean SF == ServerFault? I'd have thought it to be a Stack Overflow (SO) question, myself.
    – Joe
    Commented Jan 4, 2011 at 18:17
  • 4
    I think he meant SO, this is surely a SO topic.
    – BlackICE
    Commented Jan 4, 2011 at 19:38
  • 3
    Yes, CRUD should be on SO.
    – jcolebrand Mod
    Commented Jan 5, 2011 at 3:10
  • 2
    However, what about questions on ACIDity?
    – jcolebrand Mod
    Commented Jan 5, 2011 at 3:10
  • 2
    Should be on SO
    – bernd_k
    Commented Jan 5, 2011 at 21:28
  • Should be on "programmers" or stack overflow.
    – Tangurena
    Commented Jan 6, 2011 at 20:39
  • 2
    Generally off-topic, but if it extends to locking/contention issues arising then a DBA is probably better able to suggest why than a programmer.
    – Gary
    Commented Jan 10, 2011 at 5:57
  • off topic , definitely for SO
    – paranjai
    Commented Jan 10, 2011 at 9:57
  • What about stored procedures and plugin languages for databases like PostgreSQL?
    – Kirk Roybal
    Commented Jul 15, 2014 at 16:19
  • @KirkRoybal : meta.dba.stackexchange.com/a/26/51
    – Joe
    Commented Jul 15, 2014 at 19:06

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