[Dbix-class] Caching a resultset?

[Alexander Hartmaier]

On 2013-01-16 13:20, Peter Rabbitson wrote:
> On Wed, Jan 16, 2013 at 11:03:43AM +0100, Alexander Hartmaier wrote:
>> On 2013-01-15 21:49, Peter Rabbitson wrote:
>>> On Tue, Jan 15, 2013 at 05:12:12PM +0100, Alexander Hartmaier wrote:
>>>> On 2013-01-15 16:51, Peter Rabbitson wrote:
>>>>> On Tue, Jan 15, 2013 at 10:09:19AM -0500, Jesse Sheidlower wrote:
>>>>>> On Tue, Jan 15, 2013 at 05:18:06AM +1100, Peter Rabbitson wrote:
>>>>>>> On Mon, Jan 14, 2013 at 11:07:34AM -0500, Jesse Sheidlower wrote:
>>>>>>>>> So apart from the mystery around the nonsensical exception - does this help?
>>>>>>>>>
>>>>>>>>> local $DBIx::Class::ResultSourceHandle::thaw_schema = $c->model(...)->schema;
>>>>>>>> Yes! Putting that before the "unless" seems to make everything work
>>>>>>>> correctly.... Will be testing further this afternoon. Thanks!
>>>>>>> Please let me know if wider testing is succesful.
>>>>>> In one sense, wider testing was indeed successful. The RS was cached
>>>>>> properly, it worked in several different environments, etc.
>>>>>>
>>>>>> However, it didn't "work" in one particularly crucial way, which in
>>>>>> retrospect I'm surprised I didn't think about: the resultset may have
>>>>>> been cached, but once I get it back, it's still just a resultset, so
>>>>>> when I use it again in the template, it hits the database again. Every
>>>>>> time.
>>>>>>
>>>>>> This is exactly what I wanted to avoid by this whole escapade.
>>>>> You need to combine the above with [1] and/or [2].
>>>>>
>>>>> [1] https://metacpan.org/module/DBIx::Class::ResultSet#cache
>>>>> [2] https://metacpan.org/module/DBIx::Class::ResultSet#set_cache
>>>>>
>>>>> Cheers
>>>> You mean don't prefetch the relationships and populate it's cache after
>>>> fetching all results?
>>> Um... prefetch does not touch the cache of the *main* rs. I am not sure
>>> what you mean above - explain.
>> My schema has quite some 'side tables' like types, stati and so on. They
>> almost never change.
>> It would help performance if I could tell the schema to load all rows,
>> cache them and populate a relationship from the cache when prefetched.
>> For example
>>
>> Interface->belongs_to('rel_interface_type', ::Interface_Type,
>> 'fk_interface_type');
>>
>> Schema->connect({
>>     ... ,
>>     prefetch => [qw( Interface_Type )],
>> });
> You are looking at the wrong layer.
>
> 1) At connection time tell the storage you *may* be using Cursor::Cached at
> places: [1]
>
> 2) Add the appropriate cache_for attribute to the relationships you want to
> add it to:
>   Interface->belongs_to('rel_interface_type', ::Interface_Type,
>     'fk_interface_type', {
>       cache_object => do {
>         # an instance of say Cache::FileCache, something that
>         # understands get()[2] set()[3] and remove()[4]
>         # sorry about the links to source, mst sucks at POD,
>         # docpatches more than welcome
>       },
>       cache_for => do { # sub-argument to set as in [3] }
>   );
>
> 3) Optionally register extra relationships )extra names) which never use
> the cache
>
> This way it is just granular enough to be useful, and won't require you
> to change any of the actual app logic.
>
> Cheers
>
> [1] https://metacpan.org/source/ARCANEZ/DBIx-Class-Cursor-Cached-1.001002/lib/DBIx/Class/Cursor/Cached.pm#L101
> [2] https://metacpan.org/source/ARCANEZ/DBIx-Class-Cursor-Cached-1.001002/lib/DBIx/Class/Cursor/Cached.pm#L77
> [3] https://metacpan.org/source/ARCANEZ/DBIx-Class-Cursor-Cached-1.001002/lib/DBIx/Class/Cursor/Cached.pm#L79
> [4] https://metacpan.org/source/ARCANEZ/DBIx-Class-Cursor-Cached-1.001002/lib/DBIx/Class/Cursor/Cached.pm#L86
I had NO idea that's already possible, thanks for the great pointers! Do
we want to include that in the Cookbook?
>
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