What are some cons of storing html in a database for use?

Altough its very easy to do a search about the topic, it's not as easy to come t开发者_StackOverflowo a conclusion. What are some cons of storing html in a database for use?

HTML is static, and querying the data from a database uses database resources; database resources are typically among the more restricted on moderate to heavy use systems, therefore it makes sense to not store HTML in the database, but to place it on the filesystem, where it can be retrieved without using critical resources.

In the broadest sense, HTML is a document markup language and serves to structure data into a document. The database on the other hand should contain raw data organized along its logical relations. Documents use formatting and may present data redundantly, but the true, underlying data is always fixed. Thus you should store the most immediate, raw form of data that you possibly can, and retrieve it in meaningful ways using both the query language itself to create suitable views for your purposes, and other, output-specific data processing to generate documents.

Of course you may like to cache the result of an output formatting operation, and you may choose to store the cache in a database, too. That's fine of course. But concerning the raw payload data, I would always go for the above.

That depends on the use of the HTML in the database. If it's data that you only ever access as a blob (meaning you never/rarely query the contents of the HTML), then I think it can be a good idea in some cases. Then the question is essentially the same as "Should I store files in xyz format in my database?" And the answer to questions like that depends on several things:

1. How large are the files? Would storing them on the filesystem, with just their filename/path in the DB be more efficient?
2. Do you need to replicate the data to other servers? If so, then storing raw files in the DB may be easier than on the FS, if you already have DB-sync infrastructure in place.
3. What are your query uses like? Are they friendlier to a DB or a file system storage?

Now, if you're talking about storing HTML data that you frequently have to query, that changes the game entirely.

Any database normalization nazi would tell you never to do it. But there might be cases when it's useful. For instance, if you're using some sort of full-text searching engine, you may want that in a database--or in whatever form the full-text search engine uses.