https://hobo.lighthouseapp.com/projects/8324/tickets/261-calling-respond_to-on-something-that-might-be-a-scoped-association-can-cause-the-full-collection-to-load
Yep, that's probably the most likely culprit. On Thu, Aug 13, 2009 at 4:40 PM, Matt Jones <[email protected]> wrote: > > There's a old bug that we still haven't pinned down that sometimes > causes extra association loads when calling respond_to? on an > AssociationCollection. I don't have the Lighthouse number handy, but > it's a known issue (possibly with AR itself and not Hobo). > > This may be a related issue. > > --Matt Jones > > On Aug 13, 2009, at 7:14 PM, Scott Bronson wrote: > > > I don't see why the count tag would be loading your whole > > association. Here's the full line: > > > > c = this.try.to_int || this.try.total_entries || (this.try.loaded? > > && this.try.length) || this.try.count || this.try.length > > > > piece by piece: > > > > this.try.to_int: would never load an association > > this.try.total_entries: just an attr_reader, will never load > > (this.try.loaded? && this.try.length): won't load if it's not > > already loaded > > this.try.count: would fire off a COUNT but won't load > > anything > > this.try.length: finally, yes, this would load the assoc > > > > > > So, if your association is already loaded, (this.try.loaded? && > > this.try.length) would fire and compute the length from the array. > > If not, this.try.count would fire off a SQL COUNT. > > > > Either way, it should already behave exactly like this.try.size. It > > should not cause any associations to be loaded. > > > > Can you explain more? > > > > - Scott > > > > > > Some notes, probably ignroable... > > > > > > Trying to figure out the intent behind that line of code... > > > > first, check to see if the argument is already numeric: > > this.try.to_int > > works for: Integer, Float, Numeric, BigDecimal > > (It also works for Symbol, which is unfortunate: > > >> :abc.to_int > > => 158489 > > Don't pass symbols to the count tag!) > > > > Then, see if you have a will_paginate collection: > > this.try.total_entries > > > > Then, duplicate the size call: (this.try.loaded? && this.try.length) > > || this.try.count > > If the association is loaded, call length, else call count. > > works for: ActiveRecord associations > > > > Finally, if count fails, fall back to length: this.try.length > > works for: anything else! > > > > > > > > Appendix 2: what's the difference between count, length and size > > anyway? > > > > In http://blog.hasmanythrough.com/2008/2/27/count-length-size Josh > > says: > > Model.count: always runs a SQL COUNT query > > Model.length: loads the association if it isn't loaded, then > > counts the array > > Model.size: like length if the association is loaded, and like > > count if it isn't > > > > I concur. count always runs the sql query: > > > > >> c=Channel.first; c.shows.count && c.shows.count && c.shows.count > > Channel Load (0.3ms) SELECT * FROM "channels" LIMIT 1 > > SQL (0.2ms) SELECT count(*) AS count_all FROM "shows" INNER JOIN > > "channel_shows" ON "shows".permid_id = "channel_shows".show_id WHERE > > (("channel_shows".channel_id = 2147005940)) > > SQL (0.2ms) SELECT count(*) AS count_all FROM "shows" INNER JOIN > > "channel_shows" ON "shows".permid_id = "channel_shows".show_id WHERE > > (("channel_shows".channel_id = 2147005940)) > > SQL (0.2ms) SELECT count(*) AS count_all FROM "shows" INNER JOIN > > "channel_shows" ON "shows".permid_id = "channel_shows".show_id WHERE > > (("channel_shows".channel_id = 2147005940)) > > => 23 > > > > length loads the association if it's not already loaded, then > > returns the array length: > > > > >> c=Channel.first; c.shows.length && c.shows.length && c.shows.length > > Channel Load (0.3ms) SELECT * FROM "channels" LIMIT 1 > > Show Load (3.6ms) SELECT "shows".* FROM "shows" INNER JOIN > > "channel_shows" ON "shows".permid_id = "channel_shows".show_id WHERE > > (("channel_shows".channel_id = 2147005940)) > > => 23 > > > > size acts like count if the association isn't loaded, and like > > length if it is: > > > > >> c=Channel.first; c.shows.size && c.shows.size && c.shows.reload > > && c.shows.size && c.shows.size > > Channel Load (0.3ms) SELECT * FROM "channels" LIMIT 1 > > SQL (0.2ms) SELECT count(*) AS count_all FROM "shows" INNER JOIN > > "channel_shows" ON "shows".permid_id = "channel_shows".show_id WHERE > > (("channel_shows".channel_id = 2147005940)) > > SQL (0.2ms) SELECT count(*) AS count_all FROM "shows" INNER JOIN > > "channel_shows" ON "shows".permid_id = "channel_shows".show_id WHERE > > (("channel_shows".channel_id = 2147005940)) > > Show Load (3.6ms) SELECT "shows".* FROM "shows" INNER JOIN > > "channel_shows" ON "shows".permid_id = "channel_shows".show_id WHERE > > (("channel_shows".channel_id = 2147005940)) > > => 23 > > > > > > > > > > On Tue, Aug 11, 2009 at 3:54 PM, kevinpfromnm > > <[email protected]> wrote: > > > > No, I haven't yet. > > > > On Aug 11, 8:18 am, Owen <[email protected]> wrote: > > > Cool. Have you alerted Bryan or Tom? > > > > > > On Aug 7, 2:02 am, kevinpfromnm <[email protected]> wrote: > > > > > > > I made one small change to a local version of the count tag and it > > > > kept it from loading the whole association every time I used it. > > > > > > > I added this.try.size || to the beginning of the c = line. The > > > > try.to_int was causing it to load the whole association. Size > > is nice > > > > because if it's already loaded it uses array length. If it's > > not, it > > > > uses count. And it will use an auto cache counter column if it's > > > > available. > > > > > > > > > > > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Hobo Users" group. 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