Monday
Feb182008
limit on the number of databases open

Have a few doubts.. here are the qs
1) is there any limit on the number of databases that can be accessed simultaneously? (MySQL)
2) will it be a problem to scale in the future if there are large number of small databases(2-5 MB) each?
1) is there any limit on the number of databases that can be accessed simultaneously? (MySQL)
2) will it be a problem to scale in the future if there are large number of small databases(2-5 MB) each?
Reader Comments (3)
In general, I'd so no to both questions but in practice it'll depend on what language & library interface you're using to access the database.
If you want to run a large number of mysql db's on the same db server you will have to think through how you allocate memory and connections. Separate db's usually require separate connections and separately thread buffers for sort/read/join etc. At least on 32bit systems (you can only allocate 2GB of buffer memory) with a lot of databases you could easily run into limitations with the number of concurrent DB connections.
My advice is to have a clear undertanding of the Mysql configuration parameters and making sure these are configured to support the way you expect your application to behave.
i dont think having large number of databases will be a problem if load is not high....
arent all the databases of shared hosting sites saved on a same server?? investigating this might help... if any of you know how shared hosting databases are hosted.. pls share them