Well, that's true of any database, but for most databases if you try to take a "snapshot" of a db file while it's running, chances are pretty good you're not going to like what you get. More often than not a transaction will have been half-written to the file when you "grab" it and back it up. And as we all know, the only thing worse than finding a worm in an apple is finding half a worm...
That's why "online backup" is a key feature requirement for any database worth it's salt. We had to implement it for Sybase, and we had to implement it for Apache Derby. What I'm hearing here is because the way CouchDB works (I'm not sure I fully grok it), at any point you take a copy of the db file, it's in a consistent state. I guess what this means is each document is written as a single atomic write, so you can't end up with half a document in your backup. I know you've told me this works, but call me paranoid - is that really true? What if the document is umpteen gajillibytes long? Is it still written as a *single atomic write* to the disk? Do you all lock the file each time you do a write? Does Time Machine lock the file from writes the whole time it's reading it/taking a snapshot of it? Just want to make really sure we're all on the same page here. Thanks, David On Thu, Jan 28, 2010 at 9:51 PM, de Saint Martin Cédric < [email protected]> wrote: > Tell me if I'm wrong, but CouchDB's databases are stored in files. > So if you backup all these files, there is no risk of corrupting your data. > Conclusion : TimeMachine will work. > > > On 29 janv. 2010, at 00:41, David Van Couvering wrote: > > > Anyone know if a TimeMachine backup of a running CouchDB will work, or is > > there a likelihood of corruption? > > > > -- > > David W. Van Couvering > > > > http://www.linkedin.com/in/davidvc > > http://davidvancouvering.blogspot.com > > http://twitter.com/dcouvering > > > -- David W. Van Couvering http://www.linkedin.com/in/davidvc http://davidvancouvering.blogspot.com http://twitter.com/dcouvering
