# Will memcache bring any benefits with a small DB set? **URL:** \ **Category:** Rails\ **Created:** [February 22, 2010, 2:57pm UTC](https://www.ruby-forum.com/t/will-memcache-bring-any-benefits-with-a-small-db-set/183902 "2010-02-22T14:57:05Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![comopasta](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/59ef9b/32.png) [@comopasta](https://www.ruby-forum.com/u/comopasta)\ **Post date:** [February 22, 2010, 2:57pm UTC](https://www.ruby-forum.com/t/will-memcache-bring-any-benefits-with-a-small-db-set/183902/1 "2010-02-22T14:57:05Z")
Hi, I have a DB that stores strings of XML. There could be hundreds of those, thousands at most. Based on client requests, a binary file is generated, most of the content in the binary file is XML taken from the DB. So there is plenty of parsing to do and several searches to collect the right pieces of XML that I need. I need persistence so I still need the DB and ActiveRecord. But I thought that if I could copy the DB into memory to speed up. This sounds like I could start playing with memcache. But somewhere I read that memcache will only be faster when dealing with millions of records. I won’t have millions of records so will this really bring me any benefits? The load from clients is expected to be heavy though. I’d appreciate your opinions. I will be playing with memcache in the meanwhile as well. Cheers. ---
**Author:** ![comopasta](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/59ef9b/32.png) [@comopasta](https://www.ruby-forum.com/u/comopasta)\ **Post date:** [February 22, 2010, 3:30pm UTC](https://www.ruby-forum.com/t/will-memcache-bring-any-benefits-with-a-small-db-set/183902/2 "2010-02-22T15:30:42Z")
On Feb 22, 1:57 pm, comopasta Gr [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > This sounds like I could start playing with memcache. > But somewhere I read that memcache will only be faster when dealing with > millions of records. I won’t have millions of records so will this > really bring me any benefits? The load from clients is expected to be > heavy though. > > I’d appreciate your opinions. > I will be playing with memcache in the meanwhile as well. It’s hard to talk in generalities about this sort of stuff as there are so many factors that come into play. Your best bet is to benchmark some stuff, also taking into account the pattern of traffic you expect (ie what proportion of cache hits do you expect?) Even in the case where memcache doesn’t make things faster (or even makes things slower) it may still help at high volume if it takes some load off your database. Fred ---
**Author:** ![comopasta](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/59ef9b/32.png) [@comopasta](https://www.ruby-forum.com/u/comopasta)\ **Post date:** [February 22, 2010, 3:50pm UTC](https://www.ruby-forum.com/t/will-memcache-bring-any-benefits-with-a-small-db-set/183902/3 "2010-02-22T15:50:36Z")
Have you had a look at your logs to see how often a particular page gets called. This will give you an idea as to how many entries you might end up with in the cache, if they are not being called repeatedly then the improvement will be slight. Or if the data changes often the the cache will become out of date too often. Also how big are these chunks of data? Again this is the sort of thing you will need to know when sizing the cache. If the data is really large then the cache may expire them before you get to reuse them. That aside parsing and combining xml documents is not the fastest thing on earth so if you can cache final format of the data and reuse it then you should get a good speedup. You need to measure things. ---
**Author:** ![comopasta](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/59ef9b/32.png) [@comopasta](https://www.ruby-forum.com/u/comopasta)\ **Post date:** [February 22, 2010, 10:04pm UTC](https://www.ruby-forum.com/t/will-memcache-bring-any-benefits-with-a-small-db-set/183902/4 "2010-02-22T22:04:59Z")
Hi, Yeah I’m on my way to start playing with memcache after checking some sites. Then I’ll make some tests and see to which side it affects performance. This app won’t be serving pages but providing binary data based on the stored records, no html, js and all the typical web app stuff. I have no patterns of terminal behavior so I can only guess at this point (of course I know the types of requests that clients will make). On the other hand there’s other areas where I need to improve performance, for example I’m thinking of have some real C code for the binary file generation, which I make now with the bindata gem. The nice thing about cache is that I can use it whenever I feel is good since it seems so easy to use, so I can revert changes or move the feature around to play with it. I also slowly started playing with load testing using apachebench so I can stress the server a bit. Thanks for your comments! Regards.