1
vote
1answer
46 views

MongoDB index strategy

I'm developing a system to back-up computers and store the files / data with retention for a while. The actual files are stored in an object store, while I'm planning to keep the metadata of the files ...
2
votes
2answers
83 views

Is it always faster to create indexes after loading data?

I have a large number of records (~1 billion) that I need to load into MongoDB (actually TokuMX, but whatever). I have about 6 different indices I need to create on the collection. Is it always faster ...
0
votes
1answer
120 views

MongoDB insert performance rapidly dropping

I'm currently experiencing a rapid decrease of the insert Performance. I have a rather simple data model { "Id": "ObjectId", "SomeProp": "xy", "SomeTags": [ { "key": ...
3
votes
1answer
97 views

How are Mongodb indexes stored on disk?

So let me first start the question with my understanding of how MongoDb stores data on disk: So when you create a database in mongodb, it allocates a large file named <databasename>.0 and within ...
1
vote
0answers
204 views

Error with Solr DataImporter using Mongodb

I've configured my environment and I've downloading Solr 4.7 The idea is make an indexing my mongodb database. For this I've installed the mongo-connector like appear here: ...
0
votes
3answers
119 views

How MongoDB indexes differs from MySQL indexes?

I am a newbie to MongoDB. I know how Indexes works and what it's importance in MySQL. Are MongoDB indexes are the same as MySQL ?
1
vote
1answer
110 views

How to find MongoDB index statistics

Is there any way we can figure out what all indexes are cached into RAM ? I want to know page related stats for individual indexes (# of hits and miss )
0
votes
1answer
126 views

Should I index before or after importing a dump?

I am using mongodb to persist a very big-size (90G), which has nearly 40,000,000 items. I read and parse this file and insert all items into mongodb (my programming language is perl, batch_insert, and ...
1
vote
1answer
278 views

optimizing MySQL for traffic analytics system

background : I've developed a URL shortener system like Bitly with same features , so the system also tracks clickers info and represent as graphs to the person who has shorten the link as ...
1
vote
2answers
285 views

Mongodb multikey index and $all in queries

I have such structure of documents in my products collection: { title: 'Samsung Galaxy S III', category_id: ObjectId("50bcc2f0b910a6c1936a4424"), properties: [ { title: 'OS', ...
0
votes
1answer
55 views

Why $in is much faster then $all

I am well aware of what those 2 do. $in take .3 seconds. And $all take 26 seconds. Huge different. If anything $in should take longer because it returns more data. Also if the limit is removed, $in ...
1
vote
1answer
763 views

How to interpret this “db.explain()” for this mongodb query

db.tablebusiness.find({ "LongitudeLatitude" : { "$within" : { "$centerSphere" : [[106.772835, -6.186753], 0.0089967464101566] } }, "indexContents" : { "$all" : ["warung"] }, "Prominent" : { "$gte" : ...
0
votes
1answer
140 views

The sort column must be the last column used in the index - MongoDB Indexing Advice

MongoDB docs advices that: The sort column must be the last column used in the index Here is the example: db.foo.ensureIndex({a: 1, b: 1, c: 1}) Good: find(a=1).sort(a) find(a=1).sort(b) ...
4
votes
1answer
870 views

How to index dynamic attributes in MongoDB

I have following kind of data (simplified a bit from my real case) in MongoDB: { "name":"some name", "attrs":[ {"n":"subject","v":"Some subject"}, {"n":"description","v":"Some ...
10
votes
1answer
1k views

How do databases store index key values (on-disk) for variable length fields?

Context This question pertains to the low-level implementation details of indexes in both SQL and NoSQL database systems. Actual structure of the index (B+ tree, hash, SSTable, etc.) is irrelevant as ...