On 8 Jan 2011, at 9:45am, srl309 wrote: > I am trying to create a system that will save frequently queried values that > are not indexed to index's. The total amount of indices allocated this way > would have a set size and would be dropped and created depending on how > often they and other values are used. I was thinking since these indices are > used frequently it would be a good idea to save them to memory dropping them > when the connection closes.
You can definitely make up ad-hoc indexes as your data is used in unexpected ways. Then, as your application is quit, just go through and delete all the indexes you've noted as temporary. But the technique of keeping indexes in memory as you describe is what a good adisk caching algorithm does. If your OS and hardware are working properly, then areas of disk frequently used should be cached. Whatever system you work out can't be more efficient than disk caching, since the caching system itself knows which areas of disk are most deserving of keeping in memory. So just make up whatever indexes you think will be used, and rely on your operating system to work out what's worth caching. Your question does make me think of premature optimization. So I suggest you write your application first. Only once you find it's too slow is it time to worry about ways to speed it up. If it turns out that the best way to improve it is to keep more of your indexes to be kept in memory, buy more RAM ! The exception is probably the case where the programmer can't possibly work out what indexes to create. For instance, if you're trying to produce a general tool for handling data, and don't know what your users are going to use the variables for. If it turns out that you really do need cached temporary indices (which is the technical name for what you describe) then you might be better-off using MySQL or one of the other implementations of SQL which has server/client architecture. Most of those have cached temporary indexing built in. Simon. _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
