Jim Starkey wrote: > Ask Bjørn Hansen wrote: >> >> On Nov 9, 2008, at 14:27, Jim Starkey wrote: >> >>> Even if it is inconvenient, it is the way to go. Why send a 50MB PDF >>> to the client if the client isn't going to actually request it? >> >> What's the real use case for that? If you don't want it, just don't >> ask for it - no?
> First, the storage engine always has to materialize the blob, even if > the record is part of an exhaustive scan and is rejected. The better solution is to not store the blob in the database, IMHO. Store the metadata about the blob, but not the blob. Use the filesystem for what it was intended. Sure, it may make backups slightly more complex, since you need to back up the filesystem and the database for critical data, but this is a minor inconvenience. > Second, the > program logic may look at non-blob fields to decide whether or not to > fetch the blob. For example, both a PDF and HTML translation may be > stored, but not all records have HTML translations. So the program > selects both and decides on a case by case basis. >> >> At least with InnoDB - IIRC - then you don't even get the page cache >> hit from the data then. >> >> And really - in what kind of application is storing that big blobs a >> good idea?[1] > All modern applications has jpegs and pdfs. It's part of the > environment. Some applications even use Word for textual data entry > because that's what 99% of the world uses. The minimum pdf is about > 50K. The minimum Word document is about 40K. Pdfs produced by crappola > scanners are more like 500K. Jpegs by modern cameras are 1 - 2MB. > > These are bad ideas only if the database is wretched at storing blobs. I see your point, but I also don't see the point of prioritizing the performance of blob storage over other things. IMHO, storing BLOBs in the DB is bad architectural design. We shouldn't focus efforts on optimizing for poor application design. -jay >> I have the impression that most of us here have spent much too much of >> our time just building Javascript driven Kitten websites; so your >> perspective is often intriguing and sometimes puzzling. :-) >> >> >> - ask >> >> [1] I have a couple applications where we use the DB as a kind of file >> system (with a small web server and squid/varnish in front) because it >> used less space and was easier to backup etc than with actual files -- >> but it's a weird use of the database and I'd never mix it with "real" >> data. >> > > > > _______________________________________________ > Mailing list: https://launchpad.net/~drizzle-discuss > Post to : [email protected] > Unsubscribe : https://launchpad.net/~drizzle-discuss > More help : https://help.launchpad.net/ListHelp _______________________________________________ Mailing list: https://launchpad.net/~drizzle-discuss Post to : [email protected] Unsubscribe : https://launchpad.net/~drizzle-discuss More help : https://help.launchpad.net/ListHelp
