Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>See if the following is in line with what you want to accomplish:</p> <pre><code>db.bbticks.aggregate( [ { $match: { time: { $gte: ISODate("2013-08-01") } } }, { $group: { _id: "$time", count: {$sum: 1}, tickers: { $push: { "ticker": "$ticker" , "close": "$close" } } } } , { $match: { count: { $gt: 1 } } } ] ) </code></pre> <p>-- break --</p> <p>For the map-reduce, you could try the following (not very elegant, I think there are better ways but just some ideas to get you started). Also, as this will be a time series that grows, chances are you might want to use an incremental map-reduce (<a href="http://docs.mongodb.org/manual/tutorial/perform-incremental-map-reduce/" rel="nofollow">http://docs.mongodb.org/manual/tutorial/perform-incremental-map-reduce/</a>). But the below can give you some ideas (like I said, it is ugly --- and it might be better to perform a second map-reduce operation rather than my last find statement, but up to you).</p> <pre><code>var mapFunction = function() { var key = this.time var value = { tickers: [ { ticker: this.ticker, close: this.close } ] }; emit( key, value ); }; var reduceFunction = function(keyObject, valuesArray) { var reducedValue = { tickers: [] }; for (var idx = 0; idx &lt; valuesArray.length; idx++) { reducedValue.tickers.push( valuesArray[idx].tickers[0] ) } return reducedValue; }; db.bbticks.mapReduce( mapFunction, reduceFunction, { out: "mr_interim_results", sort: { time: 1 }, query: { time: {$gte: ISODate("2013-08-01") } }, } ) db.mr_interim_results.find( { 'value.tickers': { $not: { $size: 1 } } } ) </code></pre>
    singulars
    1. This table or related slice is empty.
    1. POAggregate multiple time series in Mongodb, where all time series have the same timestamps available
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USKay
    1. USKay
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. POAggregate multiple time series in Mongodb, where all time series have the same timestamps available
      singulars
      1. PTQuestion
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTAcceptedByOriginator
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. CO"errmsg": "aggregation result exceeds maximum document size". Admittedly there are actually 115 series in bbticks, but since 1 August is not so long so even if I were to reduce the series number, I could be in a situation of requiring much longer history than 1 Aug so it must be robust to the 16mb doc size. Perhaps if you wouldn't mind running me through the logic of your aggregation, I might be able to play with it a bit.....
      singulars
      1. PO
      1. USThomas Browne
    2. COI think I may have to go with MapReduce because of this 16mb limitation: http://stackoverflow.com/questions/12337319/mongodb-aggregation-comparison-group-group-and-mapreduce.
      singulars
      1. PO
      1. USThomas Browne
    3. COHi Thomas - as you stated, because of the size limit, you probably should go with MapReduce. In regards to the logic of the aggregation, I first do a $match to find all the documents that match the condition of time >= "2013-08-01". Then, these matching documents are grouped by time, keeping a count and adding a field "tickers" which contain an array of tickers & closing price associated with that time. Then, from these grouping, I do another match to return only those that have count > 1.
      singulars
      1. PO
      1. USKay
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload