No, there is no limit. And you can structure them in subdirectories by using a slash in the database name. Like "your/name/here" will create 2 subdirectories with a database called "here" at the bottom.
On Thu, Mar 4, 2010 at 1:18 PM, Tom Sante <[email protected]> wrote: > Thanks. Are there any limits to the number of databases in couchdb? A few > 1000 probably won't be a problem I guess? > > On 4/03/10 11:49, Simon Metson wrote: >> >> Hi, >> Why not use a database per experiment? Do you need to process data >> across experiments? Can you store your raw data in individual databases >> and then pull summary data into a single database? >> Cheers >> Simon >> >> On 3 Mar 2010, at 22:21, Tom Sante wrote: >> >>> Hi >>> >>> The data is now stored in a mysql table with about a billion (1000 >>> million) rows. >>> These rows are the data of a genetic test (arrayCGH) and build up like >>> this: >>> >>> Every experiment (a few thousand of them total) contains measurements >>> of about 180000 genetic probes. This raw data will be analyzed and the >>> values run through different algorithms, so every probe needs to store >>> more than 1 value after the analysis is done. The values of different >>> analysis are now stored in columns in that table making it a pain if >>> we have to add a analysis to the table not yet part of the existing >>> columns. This is why a schema free document based DB is probably a >>> better fit. >>> The initial idea was to give each probe a separate document, and when >>> the original value is transform to an other value store this in the >>> same document. >>> >>> { >>> "probe_id" : 1234567890, >>> "experiment_id" : 1234567890, >>> "raw_value" : 0.43524, >>> "analysis": { "cbs" : 0.436, "CBS+GLAD" : 0.4356 } >>> } >>> >>> Once added to the database almost all changes to the data will be >>> contained within an experiment. >>> >>> MongoDB has something like collections that would be a appropriate >>> abstraction ~ experiment. But in couchdb I would have to add all these >>> probe documents in 1 big database without collections. So if I only >>> make changes to probes within an experiment this would influence the >>> views of all the other billions document in the db. Because of the >>> large number of documents it would be good to know beforehand what the >>> implications are of this performance wise? >>> >>> Any suggestions are welcome. >>> >>> Tom >> > >
