225 lines
11 KiB
Markdown
225 lines
11 KiB
Markdown
---
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layout: default
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title: Search
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nav_order: 75
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redirect_from:
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- /opensearch/rest-api/search/
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---
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# Search
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**Introduced 1.0**
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{: .label .label-purple }
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The Search API operation lets you execute a search request to search your cluster for data.
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## Example
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```json
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GET /movies/_search
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{
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"query": {
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"match": {
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"text_entry": "I am the night"
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}
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}
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}
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```
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{% include copy-curl.html %}
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## Path and HTTP Methods
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```
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GET /<target-index>/_search
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GET /_search
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POST /<target-index>/_search
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POST /_search
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```
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## URL Parameters
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All URL parameters are optional.
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Parameter | Type | Description
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:--- | :--- | :---
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allow_no_indices | Boolean | Whether to ignore wildcards that don’t match any indexes. Default is true.
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allow_partial_search_results | Boolean | Whether to return partial results if the request runs into an error or times out. Default is true.
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analyzer | String | Analyzer to use in the query string.
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analyze_wildcard | Boolean | Whether the update operation should include wildcard and prefix queries in the analysis. Default is false.
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batched_reduce_size | Integer | How many shard results to reduce on a node. Default is 512.
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cancel_after_time_interval | Time | The time after which the search request will be canceled. Request-level parameter takes precedence over cancel_after_time_interval [cluster setting]({{site.url}}{{site.baseurl}}/api-reference/cluster-settings). Default is -1.
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ccs_minimize_roundtrips | Boolean | Whether to minimize roundtrips between a node and remote clusters. Default is true.
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default_operator | String | Indicates whether the default operator for a string query should be AND or OR. Default is OR.
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df | String | The default field in case a field prefix is not provided in the query string.
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docvalue_fields | String | The fields that OpenSearch should return using their docvalue forms.
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expand_wildcards | String | Specifies the type of index that wildcard expressions can match. Supports comma-separated values. Valid values are all (match any index), open (match open, non-hidden indexes), closed (match closed, non-hidden indexes), hidden (match hidden indexes), and none (deny wildcard expressions). Default is open.
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explain | Boolean | Whether to return details about how OpenSearch computed the document's score. Default is false.
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from | Integer | The starting index to search from. Default is 0.
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ignore_throttled | Boolean | Whether to ignore concrete, expanded, or indexes with aliases if indexes are frozen. Default is true.
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ignore_unavailable | Boolean | Specifies whether to include missing or closed indexes in the response. Default is false.
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lenient | Boolean | Specifies whether OpenSearch should accept requests if queries have format errors (for example, querying a text field for an integer). Default is false.
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max_concurrent_shard_requests | Integer | How many concurrent shard requests this request should execute on each node. Default is 5.
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phase_took | Boolean | Whether to return phase-level `took` time values in the response. Default is false.
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pre_filter_shard_size | Integer | A prefilter size threshold that triggers a prefilter operation if the request exceeds the threshold. Default is 128 shards.
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preference | String | Specifies the shards or nodes on which OpenSearch should perform the search. For valid values, see [The `preference` query parameter](#the-preference-query-parameter).
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q | String | Lucene query string’s query.
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request_cache | Boolean | Specifies whether OpenSearch should use the request cache. Default is whether it’s enabled in the index’s settings.
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rest_total_hits_as_int | Boolean | Whether to return `hits.total` as an integer. Returns an object otherwise. Default is false.
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routing | String | Value used to route the update by query operation to a specific shard.
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scroll | Time | How long to keep the search context open.
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search_type | String | Whether OpenSearch should use global term and document frequencies when calculating relevance scores. Valid choices are `query_then_fetch` and `dfs_query_then_fetch`. `query_then_fetch` scores documents using local term and document frequencies for the shard. It’s usually faster but less accurate. `dfs_query_then_fetch` scores documents using global term and document frequencies across all shards. It’s usually slower but more accurate. Default is `query_then_fetch`.
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seq_no_primary_term | Boolean | Whether to return sequence number and primary term of the last operation of each document hit.
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size | Integer | How many results to include in the response.
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sort | List | A comma-separated list of <field> : <direction> pairs to sort by.
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_source | String | Whether to include the `_source` field in the response.
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_source_excludes | List | A comma-separated list of source fields to exclude from the response.
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_source_includes | List | A comma-separated list of source fields to include in the response.
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stats | String | Value to associate with the request for additional logging.
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stored_fields | Boolean | Whether the get operation should retrieve fields stored in the index. Default is false.
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suggest_field | String | Fields OpenSearch can use to look for similar terms.
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suggest_mode | String | The mode to use when searching. Available options are `always` (use suggestions based on the provided terms), `popular` (use suggestions that have more occurrences), and `missing` (use suggestions for terms not in the index).
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suggest_size | Integer | How many suggestions to return.
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suggest_text | String | The source that suggestions should be based off of.
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terminate_after | Integer | The maximum number of documents OpenSearch should process before terminating the request. Default is 0.
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timeout | Time | How long the operation should wait for a response from active shards. Default is `1m`.
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track_scores | Boolean | Whether to return document scores. Default is false.
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track_total_hits | Boolean or Integer | Whether to return how many documents matched the query.
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typed_keys | Boolean | Whether returned aggregations and suggested terms should include their types in the response. Default is true.
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version | Boolean | Whether to include the document version as a match.
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include_named_queries_score | Boolean | Whether to return scores with named queries. Default is false.
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### The `preference` query parameter
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The `preference` query parameter specifies the shards or nodes on which OpenSearch should perform the search. The following are valid values:
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- `_primary`: Perform the search only on primary shards.
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- `_replica`: Perform the search only on replica shards.
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- `_primary_first`: Perform the search on primary shards but fail over to other available shards if primary shards are not available.
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- `_replica_first`: Perform the search on replica shards but fail over to other available shards if replica shards are not available.
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- `_local`: If possible, perform the search on the local node's shards.
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- `_prefer_nodes:<node-id-1>,<node-id-2>`: If possible, perform the search on the specified nodes. Use a comma-separated list to specify multiple nodes.
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- `_shards:<shard-id-1>,<shard-id-2>`: Perform the search only on the specified shards. Use a comma-separated list to specify multiple shards. When combined with other preferences, the `_shards` preference must be listed first. For example, `_shards:1,2|_replica`.
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- `_only_nodes:<node-id-1>,<node-id-2>`: Perform the search only on the specified nodes. Use a comma-separated list to specify multiple nodes.
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- `<string>`: Specifies a custom string to use for the search. The string cannot start with an underscore character (`_`). Searches with the same custom string are routed to the same shards.
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## Request body
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All fields are optional.
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Field | Type | Description
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:--- | :--- | :---
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docvalue_fields | Array of objects | The fields that OpenSearch should return using their docvalue forms. Specify a format to return results in a certain format, such as date and time.
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fields | Array | The fields to search for in the request. Specify a format to return results in a certain format, such as date and time.
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explain | String | Whether to return details about how OpenSearch computed the document's score. Default is false.
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from | Integer | The starting index to search from. Default is 0.
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indices_boost | Array of objects | Values used to boost the score of specified indexes. Specify in the format of <index> : <boost-multiplier>
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min_score | Integer | Specify a score threshold to return only documents above the threshold.
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query | Object | The [DSL query]({{site.url}}{{site.baseurl}}/opensearch/query-dsl/index) to use in the request.
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seq_no_primary_term | Boolean | Whether to return sequence number and primary term of the last operation of each document hit.
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size | Integer | How many results to return. Default is 10.
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_source | | Whether to include the `_source` field in the response.
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stats | String | Value to associate with the request for additional logging.
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terminate_after | Integer | The maximum number of documents OpenSearch should process before terminating the request. Default is 0.
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timeout | Time | How long to wait for a response. Default is no timeout.
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version | Boolean | Whether to include the document version in the response.
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## Response body
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```json
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{
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"took": 3,
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"timed_out": false,
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"_shards": {
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"total": 1,
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"successful": 1,
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"skipped": 0,
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"failed": 0
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},
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"hits": {
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"total": {
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"value": 1,
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"relation": "eq"
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},
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"max_score": 1.0,
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"hits": [
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{
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"_index": "superheroes",
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"_id": "1",
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"_score": 1.0,
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"_source": {
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"superheroes": [
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{
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"Hero name": "Superman",
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"Real identity": "Clark Kent",
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"Age": 28
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},
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{
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"Hero name": "Batman",
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"Real identity": "Bruce Wayne",
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"Age": 26
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},
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{
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"Hero name": "Flash",
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"Real identity": "Barry Allen",
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"Age": 28
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},
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{
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"Hero name": "Robin",
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"Real identity": "Dick Grayson",
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"Age": 15
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}
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]
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}
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}
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]
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}
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}
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```
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## The `ext` object
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Starting with OpenSearch 2.10, plugin authors can add an `ext` object to the search response. The purpose of the `ext` object is to contain plugin-specific response fields. For example, in conversational search, the result of Retrieval Augmented Generation (RAG) is a single "hit" (answer). Plugin authors can include this answer in the search response as part of the `ext` object so that it is separate from the search hits. In the following example response, the RAG result is in the `ext.retrieval_augmented_generation.answer` field:
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```json
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{
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"took": 3,
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"timed_out": false,
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"_shards": {
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"total": 3,
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"successful": 3,
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"skipped": 0,
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"failed": 0
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},
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"hits": {
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"total": {
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"value": 110,
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"relation": "eq"
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},
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"max_score": 0.55129033,
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"hits": [
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{
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"_index": "...",
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"_id": "...",
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"_score": 0.55129033,
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"_source": {
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"text": "...",
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"title": "..."
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}
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},
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{
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...
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}
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...
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{
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...
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}
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],
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}, // end of hits
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"ext": {
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"retrieval_augmented_generation": { // a search response processor
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"answer": "RAG answer"
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}
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}
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}
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```
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