white crystal
I have huge database model of around 1 million records, and on request I only want to get last 50 records from the database. Currently I do that by this
$models = Model::latest('id')->take(50)->get();
but when I look at debugbar, it shows 1 mil models were used, it also used a big amount of memory and rapidly slowed the request.
Is there any way of not storing whole database model into memory and just take those last records ?
jolly flare
Are you sure that's where it originates from? Afaik that would end up with a query like select * from models order by id DESC limit 50 so that wouldn't load all records.
And running that locally with an explain results in the following; https://explainmysql.com/e/SraYEVQYlo9WBWe6RrNgtL, so I guess it won't be an expensive query either
left lantern
It's probably another line of code that loads all those rows/models
jolly flare
@white crystal 
white crystal
sorry I have been on dinner
and yeah, I found what si causing it
// changed this:
Model::latest()->pluck('id')->first()
// into this:
Model::latest()->first()->id
that was loading id of all records I guess and after that took the first one
left lantern
Yeah, you can do ->first('id')->id if you want to change that SELECT * to SELECT id
white crystal
Yeah, you can do `->first('id')->id` if you want to change that `SELECT *` to ` ...
you mean ->first('id') ?
left lantern
That performs a SELECT id FROM ... WHERE ... and loads that specific model, yes.
If you then want the primitive id value, you do ->id
first() performs a SELECT *. If you only need the id column (like you wrote before), then first('id') is much more performant
white crystal
I understand
jolly flare
Great, so this is solved then? 🙂