design - Collection data modeling in mongoDB -

-

i want design model profiles interaction, example <-> interact <-> b , interaction contains common fields , b.
lets have collection called interactions, have few thoughts in mind , looking best practice solution.

  1. separate interaction 2 different documents, 1 each profile 

    {   pid:"a id"   commonfield1:""   commonfield2:""   ..  } {   pid:"b id"   commonfield1:""   commonfield2:""   .. }

    pros: fast read
    cons: each update common field should performed on both of documents

  2. maintain 1 document interaction

    {  pids:['a id','b id']  commonfield1:""  commonfield2:""  .. }

    pros: update common field once
    cons: tricky read

the thing there lot of reading lot of updating , collection should designed lot of millions of documents.

common queries in scenarios:

  • retrieve profile interactions
  • update specific profile interaction

i leaning second choice relying on multikey index on pids fast document lookup , enjoying in single update in each frequent change.

i have no experience in sharded collections have noticed multikey index not supported sharding key, should show stopper second choice?
does reads fast enough kind of index? , other choices use case?

your answer highly appreciated.

i think latter format makes more sense avoid duplication of updates.

for interaction pairs should using compound index rather array. compound index can be used _id , shard key (arrays not valid either).

so document might like:

{     _id: { pid1: 'a', pid2: 'b' },     commonfield1: '',     commonfield2: '', }

if want avoid duplicate pairs sort ids in predictable order. example, pid1 might lesser of 2 values.

the default _id index allow efficiently either (pid1,pid2) or (pid1) interactions, you'll want add index on {'_id.pid2': 1}.


Comments

Post a Comment

Popular posts from this blog

python - Subclassed QStyledItemDelegate ignores Stylesheet -

-
i'm trying subclass qstyleditemdelegate remove focus rectangle in qcombobox . even though i'm calling base implementation of paint function , nothing else, result different. looks if parts of style-sheet influence bounding box of item taken consideration. class pstyleditemdelegate(qstyleditemdelegate): def __init__(self, *args, **kwds): super(pstyleditemdelegate, self).__init__(*args, **kwds) def paint(self, *args, **kwargs): qstyleditemdelegate.paint(*args, **kwargs) what have paint unmodified qstyleditemdelegate ? as suggested tried replacing pyside pyqt4 , works, appears bug. update pyside 1.1.2 1.2.1 result same. unfortunately switch breaks other parts of code, if there no other suggestions i'm going accept answer. edit bug tracked here
Read more

java - HttpClient 3.1 Connection pooling vs HttpClient 4.3.2 -

-
i have used httpclient3.1(java) connection pooling below : import org.apache.commons.httpclient.httpclient; import org.apache.commons.httpclient.multithreadedhttpconnectionmanager; import org.apache.commons.httpclient.params.httpclientparams; import org.apache.commons.httpclient.params.httpmethodparams; import org.apache.log4j.logger; public class httpclientmanager { private static logger logger = logger.getlogger(httpclientmanager.class); private static multithreadedhttpconnectionmanager connectionmanager = new multithreadedhttpconnectionmanager(); private static httpclientparams clientparams = new httpclientparams(); static { try { clientparams.makelenient(); clientparams.setauthenticationpreemptive(false); clientparams.setparameter(httpmethodparams.so_timeout, new integer(30000)); // set so_timeout clientparams.setparameter(httpmethodparams.head_body_check_timeout, new integer(3000)); // head responses ...
Read more

node.js - StackOverflow API not returning JSON -

-
i using node.js script gather data stackoverflow. know responses gzipped, put code in should take care of that. script follows: var request = require('request'); var zlib = require('zlib'); function getstackoverflowresponse(url, callback){ request(url, {encoding: null}, function(err, response, body){ if(response.headers['content-encoding'] == 'gzip'){ zlib.gunzip(body, function(err, dezipped) { callback(dezipped); }); } else { callback(body); } }); } var url = "https://api.stackexchange.com/docs/questions#pagesize=2&order=desc&min=2014-01-04&max=2014-02-02&sort=activity&tagged=apigee&filter=default&site=stackoverflow&run=true"; getstackoverflowresponse(url, function(questions) { console.log(questions); }); instead of getting json output, i'm getting following response: buffer 0d 0a 0d 0a 0d 0a 0d 0a 3c 21 44 4f 43 54 59 50 45 20 48...
Read more