Ok I changed cache.ram, 0 to cache.ram, 3600 in the first query as well - I'm assuming web2py knows when something is not in cache, and has to be fetched from db. This makes the "misses" count remain static (not incrementing), and results are correct as well.
On Jul 23, 3:28 pm, Adi <[email protected]> wrote: > Number of 'misses' is incrementing by one every time. This means cache > technique is not working? > > On Jul 23, 3:23 pm, mdipierro <[email protected]> wrote: > > > > > correction > > > cache.ram.storage['web2py_cache_statistics']['total_hits'] > > > counts total calls to cache function while > > > cache.ram.storage['web2py_cache_statistics']['misses'] > > > counts misses, i.e. result not found in cache and recomputed. > > I guess you want to monitor the latter. > > > Massimo > > > On Jul 23, 5:21 am, mdipierro <[email protected]> wrote: > > > > cache.ram.storage['web2py_cache_statistics']['total_hits'] is a > > > counter and you can read its status before and after. > > > Mind it will be affected by other concurrent ptocesses. > > > > On Jul 23, 5:09 am, Adi <[email protected]> wrote: > > > > > Seems to work. One last question - how can I check if a particular > > > > call hit the db or not? > > > > > On Jul 23, 3:03 pm, Adi <[email protected]> wrote: > > > > > > Great. That's what I was looking for - in memory filtering. Will try > > > > > and let you know! > > > > > > On Jul 23, 3:02 pm, mdipierro <[email protected]> wrote: > > > > > > > No because they two queries are different. The second query will not > > > > > > find the cached results from the first and pull them again. > > > > > > > You can do > > > > > > > def index(): > > > > > > videos = db( myquery ).select(cache=(cache.ram,0)) # myquery is > > > > > > across multiple tables, with joins. > > > > > > > def favorites(): > > > > > > fav_videos =db( myquery ).select(cache=(cache.ram, > > > > > > 3600)).find(lambda row: row.video.folder=='favorites') > > > > > > > The find command will give you a subset of an existing Rows object > > > > > > (in > > > > > > this case the cached one) > > > > > > > On Jul 23, 4:52 am, Adi <[email protected]> wrote: > > > > > > > > Ok I'm going to bug you a little more till I understand this well > > > > > > > enough :) > > > > > > > > there are two functions in controller: > > > > > > > def index(): > > > > > > > # here I will hit database because user first comes here > > > > > > > videos = db( myquery ).select(cache=(cache.ram,0)) # myquery > > > > > > > is > > > > > > > across multiple tables, with joins. > > > > > > > > def favorites(): > > > > > > > # here I want to get a subset of "videos" > > > > > > > fav_videos = db( myquery & db.videos.folder == > > > > > > > 'favorites').select(cache=(cache.ram, 3600)) > > > > > > > # this query should not hit database because of the earlier > > > > > > > query > > > > > > > in index() > > > > > > > > Is this the correct behavior? > > > > > > > > On Jul 23, 2:45 pm, mdipierro <[email protected]> wrote: > > > > > > > > > You place > > > > > > > > > videos=db(db.video.id>0).select(cache=(cache.ram,0)) > > > > > > > > > where you want the videos to be extracted from db. > > > > > > > > > videos=db(db.video.id>0).select(cache=(cache.ram,3600)) > > > > > > > > > everywhere you need to get the list of videos. > > > > > > > > > On Jul 23, 4:38 am, Adi <[email protected]> wrote: > > > > > > > > > > But where will I place this query, for "videos" to be > > > > > > > > > accessible > > > > > > > > > everywhere else? > > > > > > > > > > On Jul 23, 2:29 pm, mdipierro <[email protected]> wrote: > > > > > > > > > > > videos=db(db.video.id>0).select(cache=(cache.ram,3600)) > > > > > > > > > > > 3600 are seconds and it is the cache time. If you replace > > > > > > > > > > the value > > > > > > > > > > with 0, it will be re-computed. > > > > > > > > > > > On Jul 23, 4:13 am, Adi <[email protected]> wrote: > > > > > > > > > > > > Hi all, > > > > > > > > > > > > I have this use-case: > > > > > > > > > > > > There is a set of rows being queried from the database. > > > > > > > > > > > > videos=db(db.video.id>0).select() > > > > > > > > > > > > Now I have three different views (in same controller) > > > > > > > > > > > where I want to > > > > > > > > > > > access these rows (with additional filters), but I want > > > > > > > > > > > to prevent > > > > > > > > > > > multiple db calls. > > > > > > > > > > > > def index(): > > > > > > > > > > > # use videos here with an additional filter > > > > > > > > > > > home_videos = [v for v in videos if v.folder == > > > > > > > > > > > 'home'] > > > > > > > > > > > > def favorites(): > > > > > > > > > > > fav_videos = [v for v in videos if v.folder == > > > > > > > > > > > 'favorites'] > > > > > > > > > > > > These views essentially fetch subset of the same dataset > > > > > > > > > > > and display > > > > > > > > > > > them. > > > > > > > > > > > > Question: > > > > > > > > > > > ------------- > > > > > > > > > > > Is there a way to "cache" the first db call "videos = ... > > > > > > > > > > > " and be > > > > > > > > > > > able to access "videos" variable without hitting database > > > > > > > > > > > again, as > > > > > > > > > > > long as this session exists? > > > > > > > > > > > > I am not sure if and how I can use global variables here, > > > > > > > > > > > and will > > > > > > > > > > > they reliably persist.
