Getting one or more Documents from each Type











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I have the following problem with CouchDB:
I want to have an application for Devices with many Sensors of various type. Each device has its own database.



The content of one database looks somehow like this:



{
"_id": "xxxxx1",
"type": "sensor1",
"value": "23"
}
{
"_id": "xxxxx2",
"type": "sensor1",
"value": "42"
}
{
"_id": "xxxxx3",
"type": "sensor2",
"value": "474"
}
{
"_id": "xxxxx4",
"type": "sensor1",
"value": "86"
}
....


So I have many measurements. The id is incrementing.
When I do a GET request to a certain view, the result should be one (or better the latest) document from every type.



For example:



{
"_id": "xxxxx3",
"type": "sensor2",
"value": "474"
}
{
"_id": "xxxxx4",
"type": "sensor1",
"value": "86"
}
....


The different values are unknown, so I can not just use some "if(doc.type =="value1")" conditions in the mapping function.



Any advice? Is it even possible to do efficiently, if one database can have several thousand entries, and up to 100 different types?










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  • stackoverflow.com/questions/10389110/…
    – Alexis Côté
    Nov 22 at 19:48















up vote
0
down vote

favorite












I have the following problem with CouchDB:
I want to have an application for Devices with many Sensors of various type. Each device has its own database.



The content of one database looks somehow like this:



{
"_id": "xxxxx1",
"type": "sensor1",
"value": "23"
}
{
"_id": "xxxxx2",
"type": "sensor1",
"value": "42"
}
{
"_id": "xxxxx3",
"type": "sensor2",
"value": "474"
}
{
"_id": "xxxxx4",
"type": "sensor1",
"value": "86"
}
....


So I have many measurements. The id is incrementing.
When I do a GET request to a certain view, the result should be one (or better the latest) document from every type.



For example:



{
"_id": "xxxxx3",
"type": "sensor2",
"value": "474"
}
{
"_id": "xxxxx4",
"type": "sensor1",
"value": "86"
}
....


The different values are unknown, so I can not just use some "if(doc.type =="value1")" conditions in the mapping function.



Any advice? Is it even possible to do efficiently, if one database can have several thousand entries, and up to 100 different types?










share|improve this question
























  • stackoverflow.com/questions/10389110/…
    – Alexis Côté
    Nov 22 at 19:48













up vote
0
down vote

favorite









up vote
0
down vote

favorite











I have the following problem with CouchDB:
I want to have an application for Devices with many Sensors of various type. Each device has its own database.



The content of one database looks somehow like this:



{
"_id": "xxxxx1",
"type": "sensor1",
"value": "23"
}
{
"_id": "xxxxx2",
"type": "sensor1",
"value": "42"
}
{
"_id": "xxxxx3",
"type": "sensor2",
"value": "474"
}
{
"_id": "xxxxx4",
"type": "sensor1",
"value": "86"
}
....


So I have many measurements. The id is incrementing.
When I do a GET request to a certain view, the result should be one (or better the latest) document from every type.



For example:



{
"_id": "xxxxx3",
"type": "sensor2",
"value": "474"
}
{
"_id": "xxxxx4",
"type": "sensor1",
"value": "86"
}
....


The different values are unknown, so I can not just use some "if(doc.type =="value1")" conditions in the mapping function.



Any advice? Is it even possible to do efficiently, if one database can have several thousand entries, and up to 100 different types?










share|improve this question















I have the following problem with CouchDB:
I want to have an application for Devices with many Sensors of various type. Each device has its own database.



The content of one database looks somehow like this:



{
"_id": "xxxxx1",
"type": "sensor1",
"value": "23"
}
{
"_id": "xxxxx2",
"type": "sensor1",
"value": "42"
}
{
"_id": "xxxxx3",
"type": "sensor2",
"value": "474"
}
{
"_id": "xxxxx4",
"type": "sensor1",
"value": "86"
}
....


So I have many measurements. The id is incrementing.
When I do a GET request to a certain view, the result should be one (or better the latest) document from every type.



For example:



{
"_id": "xxxxx3",
"type": "sensor2",
"value": "474"
}
{
"_id": "xxxxx4",
"type": "sensor1",
"value": "86"
}
....


The different values are unknown, so I can not just use some "if(doc.type =="value1")" conditions in the mapping function.



Any advice? Is it even possible to do efficiently, if one database can have several thousand entries, and up to 100 different types?







couchdb






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edited Nov 22 at 16:07

























asked Nov 22 at 15:46









Seff2

133




133












  • stackoverflow.com/questions/10389110/…
    – Alexis Côté
    Nov 22 at 19:48


















  • stackoverflow.com/questions/10389110/…
    – Alexis Côté
    Nov 22 at 19:48
















stackoverflow.com/questions/10389110/…
– Alexis Côté
Nov 22 at 19:48




stackoverflow.com/questions/10389110/…
– Alexis Côté
Nov 22 at 19:48

















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