586 lines
18 KiB
Plaintext
586 lines
18 KiB
Plaintext
[[search-aggregations-bucket-composite-aggregation]]
|
|
=== Composite Aggregation
|
|
|
|
experimental[]
|
|
|
|
A multi-bucket aggregation that creates composite buckets from different sources.
|
|
|
|
Unlike the other `multi-bucket` aggregation the `composite` aggregation can be used
|
|
to paginate **all** buckets from a multi-level aggregation efficiently. This aggregation
|
|
provides a way to stream **all** buckets of a specific aggregation similarly to what
|
|
<<search-request-scroll, scroll>> does for documents.
|
|
|
|
The composite buckets are built from the combinations of the
|
|
values extracted/created for each document and each combination is considered as
|
|
a composite bucket.
|
|
|
|
//////////////////////////
|
|
|
|
[source,js]
|
|
--------------------------------------------------
|
|
PUT /sales
|
|
{
|
|
"mappings": {
|
|
"docs": {
|
|
"properties": {
|
|
"product": {
|
|
"type": "keyword"
|
|
},
|
|
"timestamp": {
|
|
"type": "date"
|
|
},
|
|
"price": {
|
|
"type": "long"
|
|
},
|
|
"shop": {
|
|
"type": "keyword"
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
POST /sales/docs/_bulk?refresh
|
|
{"index":{"_id":0}}
|
|
{"product": "mad max", "price": "20", "timestamp": "2017-05-09T14:35"}
|
|
{"index":{"_id":1}}
|
|
{"product": "mad max", "price": "25", "timestamp": "2017-05-09T12:35"}
|
|
{"index":{"_id":2}}
|
|
{"product": "rocky", "price": "10", "timestamp": "2017-05-08T09:10"}
|
|
{"index":{"_id":3}}
|
|
{"product": "mad max", "price": "27", "timestamp": "2017-05-10T07:07"}
|
|
{"index":{"_id":4}}
|
|
{"product": "apocalypse now", "price": "10", "timestamp": "2017-05-11T08:35"}
|
|
-------------------------------------------------
|
|
// NOTCONSOLE
|
|
// TESTSETUP
|
|
|
|
//////////////////////////
|
|
|
|
For instance the following document:
|
|
|
|
[source,js]
|
|
--------------------------------------------------
|
|
{
|
|
"keyword": ["foo", "bar"],
|
|
"number": [23, 65, 76]
|
|
}
|
|
--------------------------------------------------
|
|
// NOTCONSOLE
|
|
|
|
\... creates the following composite buckets when `keyword` and `number` are used as values source
|
|
for the aggregation:
|
|
|
|
[source,js]
|
|
--------------------------------------------------
|
|
{ "keyword": "foo", "number": 23 }
|
|
{ "keyword": "foo", "number": 65 }
|
|
{ "keyword": "foo", "number": 76 }
|
|
{ "keyword": "bar", "number": 23 }
|
|
{ "keyword": "bar", "number": 65 }
|
|
{ "keyword": "bar", "number": 76 }
|
|
--------------------------------------------------
|
|
// NOTCONSOLE
|
|
|
|
==== Values source
|
|
|
|
The `values` parameter controls the sources that should be used to build the composite buckets.
|
|
There are three different types of values source:
|
|
|
|
===== Terms
|
|
|
|
The `terms` value source is equivalent to a simple `terms` aggregation.
|
|
The values are extracted from a field or a script exactly like the `terms` aggregation.
|
|
|
|
Example:
|
|
|
|
[source,js]
|
|
--------------------------------------------------
|
|
GET /_search
|
|
{
|
|
"aggs" : {
|
|
"my_buckets": {
|
|
"composite" : {
|
|
"sources" : [
|
|
{ "product": { "terms" : { "field": "product" } } }
|
|
]
|
|
}
|
|
}
|
|
}
|
|
}
|
|
--------------------------------------------------
|
|
// CONSOLE
|
|
|
|
Like the `terms` aggregation it is also possible to use a script to create the values for the composite buckets:
|
|
|
|
[source,js]
|
|
--------------------------------------------------
|
|
GET /_search
|
|
{
|
|
"aggs" : {
|
|
"my_buckets": {
|
|
"composite" : {
|
|
"sources" : [
|
|
{
|
|
"product": {
|
|
"terms" : {
|
|
"script" : {
|
|
"source": "doc['product'].value",
|
|
"lang": "painless"
|
|
}
|
|
}
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
}
|
|
}
|
|
--------------------------------------------------
|
|
// CONSOLE
|
|
|
|
===== Histogram
|
|
|
|
The `histogram` value source can be applied on numeric values to build fixed size
|
|
interval over the values. The `interval` parameter defines how the numeric values should be
|
|
transformed. For instance an `interval` set to 5 will translate any numeric values to its closest interval,
|
|
a value of `101` would be translated to `100` which is the key for the interval between 100 and 105.
|
|
|
|
Example:
|
|
|
|
[source,js]
|
|
--------------------------------------------------
|
|
GET /_search
|
|
{
|
|
"aggs" : {
|
|
"my_buckets": {
|
|
"composite" : {
|
|
"sources" : [
|
|
{ "histo": { "histogram" : { "field": "price", "interval": 5 } } }
|
|
]
|
|
}
|
|
}
|
|
}
|
|
}
|
|
--------------------------------------------------
|
|
// CONSOLE
|
|
|
|
The values are built from a numeric field or a script that return numerical values:
|
|
|
|
[source,js]
|
|
--------------------------------------------------
|
|
GET /_search
|
|
{
|
|
"aggs" : {
|
|
"my_buckets": {
|
|
"composite" : {
|
|
"sources" : [
|
|
{
|
|
"histo": {
|
|
"histogram" : {
|
|
"interval": 5,
|
|
"script" : {
|
|
"source": "doc['price'].value",
|
|
"lang": "painless"
|
|
}
|
|
}
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
}
|
|
}
|
|
--------------------------------------------------
|
|
// CONSOLE
|
|
|
|
|
|
===== Date Histogram
|
|
|
|
The `date_histogram` is similar to the `histogram` value source except that the interval
|
|
is specified by date/time expression:
|
|
|
|
[source,js]
|
|
--------------------------------------------------
|
|
GET /_search
|
|
{
|
|
"aggs" : {
|
|
"my_buckets": {
|
|
"composite" : {
|
|
"sources" : [
|
|
{ "date": { "date_histogram" : { "field": "timestamp", "interval": "1d" } } }
|
|
]
|
|
}
|
|
}
|
|
}
|
|
}
|
|
--------------------------------------------------
|
|
// CONSOLE
|
|
|
|
The example above creates an interval per day and translates all `timestamp` values to the start of its closest intervals.
|
|
Available expressions for interval: `year`, `quarter`, `month`, `week`, `day`, `hour`, `minute`, `second`
|
|
|
|
Time values can also be specified via abbreviations supported by <<time-units,time units>> parsing.
|
|
Note that fractional time values are not supported, but you can address this by shifting to another
|
|
time unit (e.g., `1.5h` could instead be specified as `90m`).
|
|
|
|
====== Time Zone
|
|
|
|
Date-times are stored in Elasticsearch in UTC. By default, all bucketing and
|
|
rounding is also done in UTC. The `time_zone` parameter can be used to indicate
|
|
that bucketing should use a different time zone.
|
|
|
|
Time zones may either be specified as an ISO 8601 UTC offset (e.g. `+01:00` or
|
|
`-08:00`) or as a timezone id, an identifier used in the TZ database like
|
|
`America/Los_Angeles`.
|
|
|
|
===== Mixing different values source
|
|
|
|
The `sources` parameter accepts an array of values source.
|
|
It is possible to mix different values source to create composite buckets.
|
|
For example:
|
|
|
|
[source,js]
|
|
--------------------------------------------------
|
|
GET /_search
|
|
{
|
|
"aggs" : {
|
|
"my_buckets": {
|
|
"composite" : {
|
|
"sources" : [
|
|
{ "date": { "date_histogram": { "field": "timestamp", "interval": "1d" } } },
|
|
{ "product": { "terms": {"field": "product" } } }
|
|
]
|
|
}
|
|
}
|
|
}
|
|
}
|
|
--------------------------------------------------
|
|
// CONSOLE
|
|
|
|
|
|
This will create composite buckets from the values created by two values source, a `date_histogram` and a `terms`.
|
|
Each bucket is composed of two values, one for each value source defined in the aggregation.
|
|
Any type of combinations is allowed and the order in the array is preserved
|
|
in the composite buckets.
|
|
|
|
[source,js]
|
|
--------------------------------------------------
|
|
GET /_search
|
|
{
|
|
"aggs" : {
|
|
"my_buckets": {
|
|
"composite" : {
|
|
"sources" : [
|
|
{ "shop": { "terms": {"field": "shop" } } },
|
|
{ "product": { "terms": { "field": "product" } } },
|
|
{ "date": { "date_histogram": { "field": "timestamp", "interval": "1d" } } }
|
|
]
|
|
}
|
|
}
|
|
}
|
|
}
|
|
--------------------------------------------------
|
|
// CONSOLE
|
|
|
|
==== Order
|
|
|
|
By default the composite buckets are sorted by their natural ordering. Values are sorted
|
|
in ascending order of their values. When multiple value sources are requested, the ordering is done per value
|
|
source, the first value of the composite bucket is compared to the first value of the other composite bucket and if they are equals the
|
|
next values in the composite bucket are used for tie-breaking. This means that the composite bucket
|
|
`[foo, 100]` is considered smaller than `[foobar, 0]` because `foo` is considered smaller than `foobar`.
|
|
It is possible to define the direction of the sort for each value source by setting `order` to `asc` (default value)
|
|
or `desc` (descending order) directly in the value source definition.
|
|
For example:
|
|
|
|
[source,js]
|
|
--------------------------------------------------
|
|
GET /_search
|
|
{
|
|
"aggs" : {
|
|
"my_buckets": {
|
|
"composite" : {
|
|
"sources" : [
|
|
{ "date": { "date_histogram": { "field": "timestamp", "interval": "1d", "order": "desc" } } },
|
|
{ "product": { "terms": {"field": "product", "order": "asc" } } }
|
|
]
|
|
}
|
|
}
|
|
}
|
|
}
|
|
--------------------------------------------------
|
|
// CONSOLE
|
|
|
|
\... will sort the composite bucket in descending order when comparing values from the `date_histogram` source
|
|
and in ascending order when comparing values from the `terms` source.
|
|
|
|
==== Size
|
|
|
|
The `size` parameter can be set to define how many composite buckets should be returned.
|
|
Each composite bucket is considered as a single bucket so setting a size of 10 will return the
|
|
first 1O composite buckets created from the values source.
|
|
The response contains the values for each composite bucket in an array containing the values extracted
|
|
from each value source.
|
|
|
|
==== After
|
|
|
|
If the number of composite buckets is too high (or unknown) to be returned in a single response
|
|
it is possible to split the retrieval in multiple requests.
|
|
Since the composite buckets are flat by nature, the requested `size` is exactly the number of composite buckets
|
|
that will be returned in the response (assuming that they are at least `size` composite buckets to return).
|
|
If all composite buckets should be retrieved it is preferable to use a small size (`100` or `1000` for instance)
|
|
and then use the `after` parameter to retrieve the next results.
|
|
For example:
|
|
|
|
[source,js]
|
|
--------------------------------------------------
|
|
GET /_search
|
|
{
|
|
"aggs" : {
|
|
"my_buckets": {
|
|
"composite" : {
|
|
"size": 2,
|
|
"sources" : [
|
|
{ "date": { "date_histogram": { "field": "timestamp", "interval": "1d" } } },
|
|
{ "product": { "terms": {"field": "product" } } }
|
|
]
|
|
}
|
|
}
|
|
}
|
|
}
|
|
--------------------------------------------------
|
|
// CONSOLE
|
|
// TEST[s/_search/_search\?filter_path=aggregations/]
|
|
|
|
\... returns:
|
|
|
|
[source,js]
|
|
--------------------------------------------------
|
|
{
|
|
...
|
|
"aggregations": {
|
|
"my_buckets": {
|
|
"buckets": [
|
|
{
|
|
"key": {
|
|
"date": 1494201600000,
|
|
"product": "rocky"
|
|
},
|
|
"doc_count": 1
|
|
},
|
|
{
|
|
"key": { <1>
|
|
"date": 1494288000000,
|
|
"product": "mad max"
|
|
},
|
|
"doc_count": 2
|
|
}
|
|
]
|
|
}
|
|
}
|
|
}
|
|
--------------------------------------------------
|
|
// TESTRESPONSE[s/\.\.\.//]
|
|
|
|
<1> The last composite bucket returned by the query.
|
|
|
|
The `after` parameter can be used to retrieve the composite buckets that are **after**
|
|
the last composite buckets returned in a previous round.
|
|
For the example below the last bucket is `"key": [1494288000000, "mad max"]` so the next
|
|
round of result can be retrieved with:
|
|
|
|
[source,js]
|
|
--------------------------------------------------
|
|
GET /_search
|
|
{
|
|
"aggs" : {
|
|
"my_buckets": {
|
|
"composite" : {
|
|
"size": 2,
|
|
"sources" : [
|
|
{ "date": { "date_histogram": { "field": "timestamp", "interval": "1d", "order": "desc" } } },
|
|
{ "product": { "terms": {"field": "product", "order": "asc" } } }
|
|
],
|
|
"after": { "date": 1494288000000, "product": "mad max" } <1>
|
|
}
|
|
}
|
|
}
|
|
}
|
|
--------------------------------------------------
|
|
// CONSOLE
|
|
|
|
<1> Should restrict the aggregation to buckets that sort **after** the provided values.
|
|
|
|
==== Sub-aggregations
|
|
|
|
Like any `multi-bucket` aggregations the `composite` aggregation can hold sub-aggregations.
|
|
These sub-aggregations can be used to compute other buckets or statistics on each composite bucket created by this
|
|
parent aggregation.
|
|
For instance the following example computes the average value of a field
|
|
per composite bucket:
|
|
|
|
[source,js]
|
|
--------------------------------------------------
|
|
GET /_search
|
|
{
|
|
"aggs" : {
|
|
"my_buckets": {
|
|
"composite" : {
|
|
"sources" : [
|
|
{ "date": { "date_histogram": { "field": "timestamp", "interval": "1d", "order": "desc" } } },
|
|
{ "product": { "terms": {"field": "product" } } }
|
|
]
|
|
},
|
|
"aggregations": {
|
|
"the_avg": {
|
|
"avg": { "field": "price" }
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
--------------------------------------------------
|
|
// CONSOLE
|
|
// TEST[s/_search/_search\?filter_path=aggregations/]
|
|
|
|
\... returns:
|
|
|
|
[source,js]
|
|
--------------------------------------------------
|
|
{
|
|
...
|
|
"aggregations": {
|
|
"my_buckets": {
|
|
"buckets": [
|
|
{
|
|
"key": {
|
|
"date": 1494460800000,
|
|
"product": "apocalypse now"
|
|
},
|
|
"doc_count": 1,
|
|
"the_avg": {
|
|
"value": 10.0
|
|
}
|
|
},
|
|
{
|
|
"key": {
|
|
"date": 1494374400000,
|
|
"product": "mad max"
|
|
},
|
|
"doc_count": 1,
|
|
"the_avg": {
|
|
"value": 27.0
|
|
}
|
|
},
|
|
{
|
|
"key": {
|
|
"date": 1494288000000,
|
|
"product" : "mad max"
|
|
},
|
|
"doc_count": 2,
|
|
"the_avg": {
|
|
"value": 22.5
|
|
}
|
|
},
|
|
{
|
|
"key": {
|
|
"date": 1494201600000,
|
|
"product": "rocky"
|
|
},
|
|
"doc_count": 1,
|
|
"the_avg": {
|
|
"value": 10.0
|
|
}
|
|
}
|
|
]
|
|
}
|
|
}
|
|
}
|
|
--------------------------------------------------
|
|
// TESTRESPONSE[s/\.\.\.//]
|
|
|
|
==== Index sorting
|
|
|
|
By default this aggregation runs on every document that match the query.
|
|
Though if the index sort matches the composite sort this aggregation can optimize
|
|
the execution and can skip documents that contain composite buckets that would not
|
|
be part of the response.
|
|
|
|
For instance the following aggregations:
|
|
|
|
[source,js]
|
|
--------------------------------------------------
|
|
GET /_search
|
|
{
|
|
"aggs" : {
|
|
"my_buckets": {
|
|
"composite" : {
|
|
"size": 2,
|
|
"sources" : [
|
|
{ "date": { "date_histogram": { "field": "timestamp", "interval": "1d", "order": "asc" } } },
|
|
{ "product": { "terms": { "field": "product", "order": "asc" } } }
|
|
]
|
|
}
|
|
}
|
|
}
|
|
}
|
|
--------------------------------------------------
|
|
// CONSOLE
|
|
|
|
\... is much faster on an index that uses the following sort:
|
|
|
|
[source,js]
|
|
--------------------------------------------------
|
|
PUT twitter
|
|
{
|
|
"settings" : {
|
|
"index" : {
|
|
"sort.field" : ["timestamp", "product"],
|
|
"sort.order" : ["asc", "asc"]
|
|
}
|
|
},
|
|
"mappings": {
|
|
"sales": {
|
|
"properties": {
|
|
"timestamp": {
|
|
"type": "date"
|
|
},
|
|
"product": {
|
|
"type": "keyword"
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
--------------------------------------------------
|
|
// CONSOLE
|
|
|
|
WARNING: The optimization takes effect only if the fields used for sorting are single-valued and follow
|
|
the same order as the aggregation (`desc` or `asc`).
|
|
|
|
If only the aggregation results are needed it is also better to set the size of the query to 0
|
|
and `track_total_hits` to false in order to remove other slowing factors:
|
|
|
|
[source,js]
|
|
--------------------------------------------------
|
|
GET /_search
|
|
{
|
|
"size": 0,
|
|
"track_total_hits": false,
|
|
"aggs" : {
|
|
"my_buckets": {
|
|
"composite" : {
|
|
"size": 2,
|
|
"sources" : [
|
|
{ "date": { "date_histogram": { "field": "timestamp", "interval": "1d" } } },
|
|
{ "product": { "terms": { "field": "product" } } }
|
|
]
|
|
}
|
|
}
|
|
}
|
|
}
|
|
--------------------------------------------------
|
|
// CONSOLE
|
|
|
|
See <<index-modules-index-sorting, index sorting>> for more details. |