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I'm in the planning phase of developing a very tag heavy website. Everything will essentially be associated with tags and the entire site would be based on searching these tags.
Now, I've been thinking a lot about going the nosql route here, since from what I read and understand, it makes the most sense for something like this.
Would it be best to go with this database system? Would it makes sense to go with the relational database system? Should I think incorporating something like SOLR?
What would the ideal setup be?
UPDATE:
Ideally they would be user generated, but we all know how that would turn out with giving users that much power. So, let’s change up the requirements and say that users WILL NOT have the power to create tags.
Searching on tags based on text matches is something that would probably be useful and needed. If the tag is “garage sale”, the search for “sale” should also pick this up, at a lower relevance for sure.
I can’t imagine the usage being so much that scaling would be an issue.
Thanks
I would spend a bit of time thinking about these tags. For example, are these tags going to be user generated or will you provide a few tags and let users select which ones they want?
Will you need to search on tags based on text matches? For example if a tag is "garage sale" do you want to search for "sale" to also pick this up? Maybe at a lower relevance?
Also, what kind of usage are you looking at? One good thing about Solr is that it's super easy to scale and synchronize data, it is easy to deploy multiple nodes, shard collections and replicate data to other nodes, something that traditional databases struggle with.
Another thing to keep in mind is that most of the time, Solr is not the official "repository of record", most of the time the data gets fed to it from a DB somewhere, but all reading activities are done from Solr.
See this answer for a SQL solution. Offhand I can't think of any advantage to using most NoSQL databases (i.e. key-value, columnar, or document) as the SQL solution will be more compact and ought to give good performance; a graph database may be appropriate if you're doing a lot of navigational type queries on your tags, but it doesn't sound like that's the case.
Use of Solr (or ElasticSearch or whatever) is orthogonal to your primary database; it may be appropriate to incorporate a search tool if users are typing inexact tags for search, but I recommend integrating a stemming library or something along those lines before turning to a full blown search tool.
I am trying to design a database with search-ability at its core. My knowledge of database design and SQL is all self-taught and still fairly beginner-level, so my questions may possibly have easy answers.
Suppose I have a single table containing a large number of records. For example, suppose that each record contains details of a different computer application (name, developer, version number, etc). A list of keywords are associated with each record, such as a list of programming languages used to write the applications.
I wish to be able to enter one or more keywords (each separated by a space) into a search box, and I wish to have all associated records returned. How should I design the database to store the keywords, and what SQL query would I need to apply to the search text? (The search should be uppercase/lowercase independent.)
My next challenge would then be to order search results by relevance, and to allow entire key-phrases as well as keywords to be associated with each record. For example, if I type "Visual Basic" into the search field, I want the first results to have exactly the key-phrase "Visual Basic" associated with them. The next results should all have both keywords "Visual" and "Basic" associated with them, and the remaining results should have only one of these keywords. Again, please could anyone advise on how to implement this?
The final challenge I believe would be much harder: how much 'intelligent interpretation' can I design my database and SQL code to handle? For example, if I search for "CSS", can I get the records with the key-phrase "Cascading Style Sheets" to appear? Can I also get SQL to identify and search for similar words, such as plurals of search phrases or, for example, "programmer" or "programming" when "program" is input? Thanks!
Learn relational algebra, normalization rules, and SQL.
Start with entity relationships. Sounds like you could have an APPLICATION table as parent for a FEATURE child table, with a one-to-many relationship between the two. You'll query them by JOINing one to the other:
SELECT A.NAME, F.NAME
FROM APPLICATION AS A
JOIN FEATURE AS F
ON F.APP_ID = A.ID
Your challenges would not suggest SQL and relations to me. I would think more in terms of a parser, an indexer and search engine like Lucene, and a NoSQL document database like MongoDB.
I've come to the conclusion, after a LOT of research, that #duffymo's answer is hinting in the right direction. For the benefit of other n00bs like me, here's the conclusion I've drawn:
Many open source search engine server apps are out there to install for free. Lucene was the first I had ever heard of them, but others do exist and I think my favourite at the moment is Sphinx. As far as I can tell, the 'indexer' that #duffymo mentions is built into it. I have learnt that the indexer is the program that will examine my database for keywords and will automatically keep a record of which results should be returned for different input queries. I have also now learnt that the terminology for the behaviour I was looking for (and which Sphinx has) is 'stemming'. I'm still not sure what role a parser plays in all this...
A more basic approach would be to use SQL itself. Whilst I was already aware of the most basic of these (ie. using the LIKE keyword with 'wildcards'), I also discovered something a little more powerful: natural language / full-text search. For anyone not interested in installing a server app, I recommend you look this up.
Also, I see no reason why I would need to use NoSQL instead of SQL (as #duffymo has suggested), and so I'm going to stick with SQL for the moment (at least until I come across some good entry-level books to learn NoSQL from). Furthermore, I have very little intention to learn relational algebra until I know why I should and how it would be useful. The message here is that other beginners shouldn't be off-put by these things, as I don't think Sphinx requires any knowledge of them.
while I like #duffymo's answer, I will also suggest you research SPARQL and the wordnet project for your semantic equivalence questions.
If you choose Oracle, you can use the spatial option triple store to implement the SPARQL endpoint and do some very nice seaching like your css = Cascading Style Sheet example.
So far there've been several questions regarding this, and they've all come down to the same answer: one table for the language-neutral data, 1-* to a table with the translations and an indexed language ID field.
This has several problems:
Twice as much CRUD.
Need for Ajax CRUD if you want a decently friendly web UI.
More than twice the validation -- you need to ensure that the relationship is 1-* rather than 0-*.
Collation differences between languages isn't accommodated.
Queries require joins.
If you want slugs in multiple languages, oh boy.
A lot of database people have worked on all sorts of theoretical and practical problems, but surprisingly few people work on this one.
I think what we need ultimately is:
A field type that'll store multiple versions of strings
Multiple indices for each such field, one for each language or variation, with the option to specify the correct collation mode
A standard ORM object for this crazy thing
UI elements
Overkill? Sure, maybe, but the whole problem is a real nightmare as it is. And it's not exactly an uncommon scenario.
We gotta try to convince server vendors to work on this.
Edit: By the way, this is my first time using the community wiki; hopefully I'm doing it right.
Edit 2: Something about my wording seems to have made people think that I'm attacking the very concept of DBMS. I'm not; I'm simply saying that built-in support for localization is a much-needed feature.
I probably shouldn't have mentioned performance; it's of course completely negligible most of the time. The focus of my concern is on the fact that this really stifles productivity.
I'll provide an example. Suppose I have a very trivial table for a decidedly trivial store:
Products (id, price, description, name, slug)
In EF/MVC, I'd throw this in the ORM designer, maybe encapsulate it in a repository, build a Products controller, and have actions for Index, Details, Create, Update, Edit and Delete. To identify a product in any of the items, I'd simply do a WHERE(slug = #slug). I'd make a view model for the create/edit actions, design the form control, and wire it up straight to the repository. Done and done. To access the details for a product, the user would go to /products/details/product-slug.
But then since the rest of the website is bilingual, I decide to change the products table accordingly.
Products (id, price)
ProductsText (productId, language, description, name, slug)
Hey, that's not so bad. Yeah, not yet. Then you write your relationships and your constraints, and then you write you write out all your properties in the view-model, and then you make a complete CRUD controller for the ProductsText data or use jQuery/Ajax to add create/update/edit buttons on your Products controller, and then you add validation logic to make sure the user enters at least the primary language, and then when you want to read data for the end-user pages you write another query to take join ProductsText.slug and ProductsText.language with Products... I probably missed something, but you get the idea.
The complexity of the program just explodes with boilerplate code once you have localization involved.
Of course, I don't expect the problem to be solved completely, and it's obviously just as much a UI problem as it is a database problem. But there's just so much that could be done to make all this easier. A "multistring" field type might be a really good start.
Edit 3: Anyone ever hear of SQL Server Modeling Services? It has some localization tools in it that could be a step in the right direction. Still CTP though.
-- Simulate the French locale with the SET LANGUAGE statement.
SET LANGUAGE French
select Id, CountryName,
[System.Globalization].[SessionsString](CountryName, 1) as CountryNameString
from [Location].[CountriesTable]
What is a localized database field?
Typically in applications we've worked in, the UI is localized. This is accomplished using a database, and we put all the translations (and potentially the master phrases) in the table with a locale-code and phraseid being the primary key. This is fairly straightforward, requires a single reusable set of stored procs and has good performance and the usage is well-understood. We often allow translation on the fly so that the app interface includes a translation feature where corrections can be made and other users will see them live - either rich forms applications or web forms applications (depending on caching - which is another key feature of UI localization)
As far as querying requiring joins - that's just a fact of life in a normalized relational database, and performance there is usually managed with a good normalized design and proper indexing.
In other "data", it has made little sense to localize except under direction of the application requirements. For instance, even though you may offer a product in multiple countries, the SKU and distributor may be different. This level of localization is very application specific and we often dealt with it as a separate database and there really isn't anything tying those individually country database together - many products were not available although there may have been equivalent products in the other countries.
If you are selling the same products around the world, then you kind of fall into the original scenario in a kind of multi-lingual CMS. This requires significant work besides the low-level database. For instance, if someone corrects the default product description, what flags the translators that the translations need to also be corrected? These questions are non-trivial. Although I can see where database vendors could assist with features, these are intrinsic difficulties of application requirements and design and not necessarily something the database can add features which will universally solve.
The collation issue is indeed a little awkward. Typically data is stored in nvarchar and you would not know the collation you wanted for retrieval at the time you wrote the stored proc, since the locale would be a parameter. This only affects collections retrieved which need to be ordered by content, not usually natural key and certainly not retrieval by key - it's not a large problem, but is one which cannot easily be handled without dynamic SQL (casting using the preferred collation from a table depending upon the location passed in, if you mix data from different locales, you would have to decide if you want to sort by locale first and then it may be difficult to pick a collation which might work properly within all locales in the same result set). You are probably going to want to use a Windows collation with such a wide variety of data.
Similarly with ORMs, we typically treated the composite unique key of locale/phraseid as the key to retrieve objects (we typically also had a surrogate identity primary key) - I know that traditional ORMs don't necessarily like this departure from retrieval by a meaningless surrogate key.
I've encountered all of these issues for localized CRM-style web sites. Not fun to design and optimize, but it can be done. My 2¢ worth:
1. Twice as much CRUD.
This depends on how your CRUD is designed. Any of my stored procedures or functions that can retrieve a possibly-localized field take a locale/culture code parameter. All of these fields are also NVARCHAR to avoid encoding issues.
2. Need for Ajax CRUD if you want a decently friendly web UI.
I suppose so, but this is application-dependent. Should defer to the "internal" CRUD (DRY principle).
3. More than twice the validation -- you need to ensure that the relationship is 1-* rather than 0-*.
This also assumes that all content is required in all supported locales, instead of using a fallback mechanism. For example, Microsoft's MSDN content is available in multiple locales, but some is in only one (generally this is US English, the "neutral" locale for Microsoft).
For a CRM-style system, any locale can be used for the initial content as long as the fallback uses that if the neutral content is not available.
4. Collation differences between languages isn't accommodated.
I find that it is easier to put all collation support at the UI/reporting layer. Multilingual-aware tables with collation/locale specified on a row-by-row basis would be a very nice-to-have feature but I wouldn't like to wait for it to become available...
5. Queries require joins.
Yes, definitely makes the query a bit more complicated :-) but no real way around that. Can get even more complicated if locale fallback is included (a "locale specificity" ranking field helps here).
6. If you want slugs in multiple languages, oh boy.
This is the reason that the .NET replacement parameters in the format string were designed to be indexed, not positional (printf(), etc. are positional). An English format may need replacements in 1, 2, 3 order, while the German equivalent uses 3, 1, 2.
To make life easier for localizers, whenever I create a .NET resource bundle I document the parameters including index, data type (including minimum and/or maximum string lengths), and a contextual description - context is important for determining text gender in some locales.
Plurality may also require multiple related resources as some locales need more than just "single" and "plural" (e.g. "0 files", "1 file", "2 files").
The same rules must apply to any localizable column in the database.
Well the answers are not that helpfull so far. I had the same problem on various projects I was doing in the past. And there was never a shortcut nor a solution out of the box that helpped me to solve this problem in a easy way. But your approach is going into the right direction and with a little work on your Data Access Layer you can actualy abstract all the burden that is caused by this requirement.
So for Metadata like Types, Categories, Countries etc. performance is not an issue since the whole stuff can be cached. For freetext entries it is a different story. You most probably can't cache them and they tend to be quite long.
You might already know those pages:
http://www.codeproject.com/KB/aspnet/LocalizedSamplePart2.aspx
http://www.sisulizer.com/online-help/DatabaseLocalization.shtml
Best-practices for localizing a SQL Server (2005/2008) database
In my experience I haven't commonly run into the problem where the data stored in the database has many language-dependent versions of the same text. Typically a developed application will have many language files for all the text that's more or less statically built into the application. Then we see database data for text users enter. While an application may be used by users with many different languages, the situation where users type the same text in multiple languages is not so common. Typically uses of an application will show the UI in their language and then enter and view data in their language.
For example, users of our application in the US vs in Netherlands or Saudi Arabia would see the UI in the language of their choice, but for any given installation, the data they enter will consistently be in their native language.
Obviously this doesn't apply to all cases. CRMs are an example where you would have the same text with multiple translations, like Wikipedia, but I think what I described above is the more common scenario.
"A lot of database people have worked on all sorts of theoretical and practical problems, but surprisingly few people work on this one."
That's because there is nothing to work on, from a theoretical perspective, in your example. The so-called "problems" you mention are, all of them, nothing more than a direct consequence of the fact that you are managing more data.
"Twice as much CRUD."
And why is that a problem ? I know of at least a few systems I built that had a lot more of that than your example.
"Need for Ajax CRUD if you want a decently friendly web UI."
Is that really so ? I don't know, but at any rate how data is handled in the presentation layer, is no concern of the DBMS, and if the programmer thinks it is too difficult/cumbersome, then don't blame the DBMS for that.
More than twice the validation -- you need to ensure that the relationship is 1-* rather than 0-*.
And why is that a problem ? If more business rules are stated, more validation is required.
"Collation differences between languages isn't accommodated."
How so ? What is the sense of collating English text with French ? Of English text with Ukrainian or Russian or Chinese ? Or did you mean something else ?
"Queries require joins."
And why is that a problem ?
"If you want slugs in multiple languages, oh boy."
In what context ? For what purpose ?
SELECT language,nllabel FROM ...
NATURAL JOIN (SELECT 'EN' as language UNION SELECT 'FR' as language)
Oh but wait, I forgot ... JOINs are also a problem.
"and it's obviously just as much a UI problem as it is a database problem."
I disagree that it is. When looking at your problem from a database angle, there are two things that might possibly be a small beginning of a solution :
the possibility to do full view updating (both through JOIN and through GROUP, for your case).
the possibility to have attributes of type 'table' inside database tables. You could then have the entire set of applicable localized names-stuff as a sinle attribute in a single row for your product/...
As for full view updating : don't hold your breath. You'll suffocate long before it has arrived.
As for nested tables : they might already exist, if anyone has them Oracle will, I don't really know, but I'm not really confident that this will really make life easier on the UI side of things.
Oh, and BTW : SQL is nowhere near "theoretically pure".
I was searching the net for something like a wiki database, just like wikipedia but instead stores structured content, editable by users. What I was looking for was an online database accessible by everyone where people can design the schema and data with proper versioning of both schema and data. I couldn't find any such site. I am not sure if it is my search skills or if there really is no wiki database as of now. Does anyone out there know anything like this?
I think there is a great potential for something like this. A possible example will be a website with a GUI for querying a MySQL DB where any website visitor can create DB objects and populate data.
UPDATE: I had registered the domain wikidatabase.org to get started on a tool but I didn't find enough time yet. If anyone is interested in spending some time and coding on this, please let me know at wikidatabase.org
It's not quite what you're looking for, but Semantic Mediawiki adds database-like features to MediaWiki:
http://semantic-mediawiki.org/wiki/Semantic_MediaWiki
It's still fundamentally a Wiki, but you can add semantic tags to pages ([[foo::bar]] [[baz::1000]]) and then do database-type queries across them: SELECT baz FROM pages WHERE foo=bar would be {{#ask: [[foo::bar]] | ?baz}}. There is even an embryonic SPARQL implementation for pseudo-SQL queries.
OK this question is old, but Google led me here, so for anyone else out there looking for a wiki for structured data: Take a look at Foswiki.
This might be like what you're looking for: dbpedia.org. They're working on extracting data from Wikipedia, and encoding it in a structured format using RDF, so that it can be queried using SPARQL.
Linkeddata.org has a big list of RDF data sets.
Do you mean something like http://www.freebase.com?
You should check out https://www.wikidata.org/wiki/Wikidata:Main_Page which is a bit different but still may be of interest.
Something that might come close to your requirements is Google Docs.
What's offered is document editing roughly similar to MS Word, and spreadsheets roughly similar to Excel. I'm thinking of the latter, of course.
In Google Docs, You can create spreadsheets for free; being spreadsheets, they naturally have a row-and-column structure similar to a database, and which you can define flexibly. You can also share these sheets with other people. This seems to be a by-invite-only process rather than open-to-all, but there may be other possibilities I'm not aware of, or that level of sharing might be enough for you in any case.
mindtouch should be able to do it. It's rather easy to get data in / out. (for example: it's trivial to aggregate all the IP's for servers into one table).
I pretty much use it as a DB in the wiki itself (pages have tables, key/value..inheritance, templates, etc...) but you can also interface with the API, write dekiscript, grab the XML...
I like this idea. I have heard of some sites that are trying to pull together large datasets for various things for open consumption, but none that would allow a wiki feel.
You could start with something as simple as an installation of phpMyAdmin with a known password that would allow people to log in, create a database, edit data and query from any other site on the web.
It might suffer from more accuracy problems than wikipedia though.
OpenRecord, development of which seems to have halted in 2008, seems to approach this. It is a structured wiki in which pages are views on the data. Unlike RDBMSes it is loosely typed - the system tries to make a best guess about what data you entered, but defaults to text when it cannot guess. Schemas appear to have been implied.
http://openrecord.org
An example of the typing that is given is that of a date. If you enter '2008' in a record, the system interprets this as a date. If you enter 'unknown' however, the system allows that as well.
Perhaps you might be interested in Couch DB:
Apache CouchDB is a document-oriented
database that can be queried and
indexed in a MapReduce fashion using
JavaScript. CouchDB also offers
incremental replication with
bi-directional conflict detection and
resolution.
I'm working on an Open Source PHP / Symfony / PostgreSQL app that does this.
It allows multiple projects, each project can have multiple directories, each directory has a defined field structure. Admins set all this up.
Then members of the public can suggest new records, edit or report existing ones. All this is moderated and versioned.
It's early days yet but it basically works and is already in real world use in several projects.
Future plans already in progress include tools to help keep the data up to date, better searching/querying and field types that allow translations of content between languages.
There is more at http://www.directoki.org/
I'm surprised that nobody has mentioned Wikibase yet, which is the software that powers Wikidata.
At my work everyone has sql snippets that they use to answer questions. Some are specific to a customer, while some are generic for a given database. I want to consolidate those queries into a library/repository that can be accessed by anyone on the team. The requirements would be:
Accessible
Searchable
Tagable (multiple tags allowed per sql)
Exportable (create a document containing all queries with certain tags)
I'm interested in what has been found to work in other team environments.
You could use a wiki.
You could get started with something as simple as Tiddly wiki.
A wiki is a great approach.
For database specific or project specific snippets it's also very useful to have links to where a similar construct occurs in the code. We use trac's wiki which gives nice integration with out SVN for this.
Rather than pasting SQL snippets, I would consider graduating to an ORM (Object-Relational Mapper) or some other library to make representing and manipulating the data easier. It provides a layer of encapsulation to guard against schema changes and a layer of abstraction so you can think of the data in terms of business logic (ie. a user) rather than a collection of tables (ie. a user table, a password table, an access table...).
In Perl this would be something like DBIx::Class.
Another approach you may want to look at is creating views in your database. 'select * from some_view' can hide quite a bit of SQL. You'll still want to use a wiki to document them, but if its a view you don't have to worry about people keeping outdated copies.