Ross Bates wrote:
Hi All - I have about 600 of documents with 3 attributes:
parent, child, level
When I run the following map/reduce everything looks correct at first in
that I get an array back where the key is the level and the value is a
collection of arrays that have share the same level value. So if there were
5 unique levels there would be 5 rows
function(doc) {
emit( parseInt(doc.level), [doc.child,doc.parent]);
};
function(a,b){
return b;
}
The problem is that when I run this on a larger data set the value array
starts getting chunked into arbitrary sizes (50, 83, etc....) When I say
chunked, the row has a bunch of additional nested arrays to store the
key/value.
Is there some sort of max array size imposed by couch db?
Many Thanks,
Ross
Ross,
Firstly, the chunked bits you're seeing is couchdb running rereduce on
your reduce output. The full signature of a reduce function is:
function(keys, values, rereduce)
Where rereduce is a boolean that flags if the function is being called
on its own output.
Also, the function as you have it would eventually tip over as its
returning too much data. For your particular use case I would suggest
omitting the reduce function entirely and then doing a selection on the
map and any post-processing client side.
HTH,
Paul Davis
