performance - Is it worth batching subscriptions in Meteor? -

when displaying list of documents, can clearer write subscription @ document level (vs @ list level), in case template reused somewhere else instance. less efficient or meteor handling things magically?

more precisely, can put document logic in document template:

template.itemslist.helpers({   items: function() {     return this.itemsids.map(function(id) { return { _id: id }; });   }, });  <template name="itemslist">   {{#each items}}{{> item}}{{/each}} </template>   template.item.oncreated(function() {   this.subscribe('item', this.data._id); });  <template name="item">   {{#if template.subscriptionsready}}     ...   {{/if}} </template> 

or subscribe once documents @ list level:

template.itemslist.oncreated(function() {   this.subscribe('items', this.data.itemsids); });  template.itemslist.helpers({   items: function() {     return items.find({_id: {$in: this.itemsids}});   }, });  <template name="itemslist">   {{#if template.subscriptionsready}}     {{#each items}}{{> item}}{{/each}}   {{/if}} </template>  <template name="item">   ... </template> 

it looks second approach more efficient, since there 1 call subscription. if talking standard http requests here, there'd no doubt. since meteor socket based , handle lot of things under hood, wondering it worth trouble move logic away document list.

generally better call subscribe once. when run subscribe new params publish method re-runs, makes call db fetch needed documents , sends client. better , more efficient make 1 call db.

but makes sense if sure want display items , if there not many items in items collection.

if there big number of items (hundreds or more) better kind of pagination avoid downloading documents client.