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Added info to better explain how to use pagingSpec

This commit is contained in:
Igal Levy 2014-11-06 14:50:01 -08:00
parent 5a98fcf5b9
commit 8f0b675e23
1 changed files with 28 additions and 2 deletions
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30
docs/content/SelectQuery.md
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@ -28,7 +28,7 @@ There are several main parts to a select query:
|filter|See [Filters](Filters.html)|no| |filter|See [Filters](Filters.html)|no|
|dimensions|The list of dimensions to select. If left empty, all dimensions are returned.|no| |dimensions|The list of dimensions to select. If left empty, all dimensions are returned.|no|
|metrics|The list of metrics to select. If left empty, all metrics are returned.|no| |metrics|The list of metrics to select. If left empty, all metrics are returned.|no|
|pagingSpec|A JSON object indicating offsets into different scanned segments. Select query results will return a pagingSpec that can be reused for pagination.|yes| |pagingSpec|A JSON object indicating offsets into different scanned segments. Query results will return a `pagingIdentifiers` value that can be reused in the next query for pagination.|yes|
|context|An additional JSON Object which can be used to specify certain flags.|no| |context|An additional JSON Object which can be used to specify certain flags.|no|
The format of the result is: The format of the result is:
@ -140,4 +140,30 @@ The format of the result is:
} ] } ]
``` ```
The result returns a global pagingSpec that can be reused for the next select query. The offset will need to be increased by 1 on the client side. The `threshold` determines how many hits are returned, with each hit indexed by an offset.
The results above include:
```json
"pagingIdentifiers" : {
"wikipedia_2012-12-29T00:00:00.000Z_2013-01-10T08:00:00.000Z_2013-01-10T08:13:47.830Z_v9" : 4
},
```
This can be used with the next query's pagingSpec:
```json
{
"queryType": "select",
"dataSource": "wikipedia",
"dimensions":[],
"metrics":[],
"granularity": "all",
"intervals": [
"2013-01-01/2013-01-02"
],
"pagingSpec":{"pagingIdentifiers": {"wikipedia_2012-12-29T00:00:00.000Z_2013-01-10T08:00:00.000Z_2013-01-10T08:13:47.830Z_v9" : 5}, "threshold":5}
}
Note that in the second query, an offset is specified and that it is 1 greater than the largest offset found in the initial results. To return the next "page", this offset must be incremented by 1 with each new query. When an empty results set is recieved, the very last page has been returned.