Why I cannot see the name of the index mongodb uses?

Question

db.tablebusiness.find({ "LongitudeLatitude" : { "$nearSphere" : [106.772835, -6.186753], "$maxDistance" : 0.053980478460939611 }, "Prominent" : { "$gte" : 15 }, "indexContents" : { "$all" : [/^soto/, /^nasi/] } }).limit(200).explain();




{
        "cursor" : "GeoSearchCursor",
        "nscanned" : 48,
        **"nscannedObjects" : 48,**
        "n" : 48,
        "millis" : 8563,
        "nYields" : 0,
        "nChunkSkips" : 0,
        "isMultiKey" : false,
        "indexOnly" : false,
        "indexBounds" : {
        }
}
>

So what's the name of the index? I saw some questions where name of index do show up. Take a look here MongoDB: why doesn't sorting by multiple keys use an index? for example

I've also heard of explain(true) somewhere that's simply not documented here:

http://www.mongodb.org/display/DOCS/Explain

Note that mongodb.org/display/DOCS/Geospatial+Indexing indicates that you may only have 1 geospatial index per collection. That means that "GeoSearchCursor" must be using that one index. — Asya Kamsky
– Asya Kamsky, Commented Sep 11, 2012 at 13:39
Wait a minute. What about if we sometimes want to search dots sorted by prominent and latter want to search dots based on title. We need 2 geospatial index each of which belong to two different combination. — user4951
– user4951, Commented Sep 14, 2012 at 5:08

Macdiesel · Accepted Answer · 2012-09-12 00:49:25Z

2

I'm unsure if it's intentional or a defect but when a geospatial index is used the name of the index used is not shown in the explain plan.

Only when using a BtreeCursor is the index name show.

As noted in the comment above, there can be only one geospatial index on a collection. Under this parameter you can assume that that if the cursor is the "GeoSearchCursor" it is using the index you want for this collection.

edited Sep 12, 2012 at 0:49

answered Sep 11, 2012 at 13:09

Macdiesel

9351 gold badge9 silver badges19 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Gregor · Accepted Answer · 2012-09-11 13:28:46Z

2

This is a known issue. Please see https://jira.mongodb.org/browse/SERVER-4213

answered Sep 11, 2012 at 13:28

Gregor

1,4689 silver badges9 bronze badges

Collectives™ on Stack Overflow

Why I cannot see the name of the index mongodb uses?

2 Answers 2

Comments

Comments

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Linked

Related