Preview a transform Added in 7.2.0

GET /_transform/{transform_id}/_preview

Generates a preview of the results that you will get when you create a transform with the same configuration.

It returns a maximum of 100 results. The calculations are based on all the current data in the source index. It also generates a list of mappings and settings for the destination index. These values are determined based on the field types of the source index and the transform aggregations.

Path parameters

  • transform_id string Required

    Identifier for the transform to preview. If you specify this path parameter, you cannot provide transform configuration details in the request body.

Query parameters

  • timeout string

    Period to wait for a response. If no response is received before the timeout expires, the request fails and returns an error.

application/json

Body

  • dest object

    Additional properties are allowed.

    Hide dest attributes Show dest attributes object
  • Free text description of the transform.

  • A duration. Units can be nanos, micros, ms (milliseconds), s (seconds), m (minutes), h (hours) and d (days). Also accepts "0" without a unit and "-1" to indicate an unspecified value.

  • pivot object

    Additional properties are allowed.

    Hide pivot attributes Show pivot attributes object
    • Defines how to aggregate the grouped data. The following aggregations are currently supported: average, bucket script, bucket selector, cardinality, filter, geo bounds, geo centroid, geo line, max, median absolute deviation, min, missing, percentiles, rare terms, scripted metric, stats, sum, terms, top metrics, value count, weighted average.

    • group_by object

      Defines how to group the data. More than one grouping can be defined per pivot. The following groupings are currently supported: date histogram, geotile grid, histogram, terms.

      Hide group_by attribute Show group_by attribute object
      • * object Additional properties

        Additional properties are allowed.

        Hide * attributes Show * attributes object
        • Additional properties are allowed.

          Hide date_histogram attributes Show date_histogram attributes object
          • Values are second, 1s, minute, 1m, hour, 1h, day, 1d, week, 1w, month, 1M, quarter, 1q, year, or 1y.

          • Additional properties are allowed.

            Hide extended_bounds attributes Show extended_bounds attributes object
          • Additional properties are allowed.

            Hide hard_bounds attributes Show hard_bounds attributes object
          • field string

            Path to field or array of paths. Some API's support wildcards in the path to select multiple fields.

          • A duration. Units can be nanos, micros, ms (milliseconds), s (seconds), m (minutes), h (hours) and d (days). Also accepts "0" without a unit and "-1" to indicate an unspecified value.

          • format string

            The date format used to format key_as_string in the response. If no format is specified, the first date format specified in the field mapping is used.

          • interval string

            A duration. Units can be nanos, micros, ms (milliseconds), s (seconds), m (minutes), h (hours) and d (days). Also accepts "0" without a unit and "-1" to indicate an unspecified value.

          • Only returns buckets that have min_doc_count number of documents. By default, all buckets between the first bucket that matches documents and the last one are returned.

          • missing string
          • offset string

            A duration. Units can be nanos, micros, ms (milliseconds), s (seconds), m (minutes), h (hours) and d (days). Also accepts "0" without a unit and "-1" to indicate an unspecified value.

          • params object
            Hide params attribute Show params attribute object
            • * object Additional properties

              Additional properties are allowed.

          • script object

            Additional properties are allowed.

            Hide script attributes Show script attributes object
            • source string

              The script source.

            • id string
            • params object

              Specifies any named parameters that are passed into the script as variables. Use parameters instead of hard-coded values to decrease compile time.

            • options object
          • keyed boolean

            Set to true to associate a unique string key with each bucket and return the ranges as a hash rather than an array.

        • Additional properties are allowed.

          Hide geotile_grid attributes Show geotile_grid attributes object
        • Additional properties are allowed.

          Hide histogram attributes Show histogram attributes object
          • Additional properties are allowed.

            Hide extended_bounds attributes Show extended_bounds attributes object
            • max number

              Maximum value for the bound.

            • min number

              Minimum value for the bound.

          • Additional properties are allowed.

            Hide hard_bounds attributes Show hard_bounds attributes object
            • max number

              Maximum value for the bound.

            • min number

              Minimum value for the bound.

          • field string

            Path to field or array of paths. Some API's support wildcards in the path to select multiple fields.

          • interval number

            The interval for the buckets. Must be a positive decimal.

          • Only returns buckets that have min_doc_count number of documents. By default, the response will fill gaps in the histogram with empty buckets.

          • missing number

            The value to apply to documents that do not have a value. By default, documents without a value are ignored.

          • offset number

            By default, the bucket keys start with 0 and then continue in even spaced steps of interval. The bucket boundaries can be shifted by using the offset option.

          • script object

            Additional properties are allowed.

            Hide script attributes Show script attributes object
            • source string

              The script source.

            • id string
            • params object

              Specifies any named parameters that are passed into the script as variables. Use parameters instead of hard-coded values to decrease compile time.

            • options object
          • format string
          • keyed boolean

            If true, returns buckets as a hash instead of an array, keyed by the bucket keys.

  • source object

    Additional properties are allowed.

    Hide source attributes Show source attributes object
    • index string | array[string] Required
    • Hide runtime_mappings attribute Show runtime_mappings attribute object
      • * object Additional properties

        Additional properties are allowed.

        Hide * attributes Show * attributes object
        • fields object

          For type composite

          Hide fields attribute Show fields attribute object
          • * object Additional properties

            Additional properties are allowed.

            Hide * attribute Show * attribute object
            • type string Required

              Values are boolean, composite, date, double, geo_point, ip, keyword, long, or lookup.

        • fetch_fields array[object]

          For type lookup

          Hide fetch_fields attributes Show fetch_fields attributes object
          • field string Required

            Path to field or array of paths. Some API's support wildcards in the path to select multiple fields.

          • format string
        • format string

          A custom format for date type runtime fields.

        • Path to field or array of paths. Some API's support wildcards in the path to select multiple fields.

        • Path to field or array of paths. Some API's support wildcards in the path to select multiple fields.

        • script object

          Additional properties are allowed.

          Hide script attributes Show script attributes object
          • source string

            The script source.

          • id string
          • params object

            Specifies any named parameters that are passed into the script as variables. Use parameters instead of hard-coded values to decrease compile time.

            Hide params attribute Show params attribute object
            • * object Additional properties

              Additional properties are allowed.

          • lang string

            Any of:

            Values are painless, expression, mustache, or java.

          • options object
            Hide options attribute Show options attribute object
            • * string Additional properties
        • type string Required

          Values are boolean, composite, date, double, geo_point, ip, keyword, long, or lookup.

    • query object

      A query clause that retrieves a subset of data from the source index.

      Additional properties are allowed.

  • settings object

    Additional properties are allowed.

    Hide settings attributes Show settings attributes object
    • Specifies whether the transform checkpoint ranges should be optimized for performance. Such optimization can align checkpoint ranges with the date histogram interval when date histogram is specified as a group source in the transform config. As a result, less document updates in the destination index will be performed thus improving overall performance.

    • Defines if dates in the ouput should be written as ISO formatted string or as millis since epoch. epoch_millis was the default for transforms created before version 7.11. For compatible output set this value to true.

    • Specifies whether the transform should deduce the destination index mappings from the transform configuration.

    • Specifies a limit on the number of input documents per second. This setting throttles the transform by adding a wait time between search requests. The default value is null, which disables throttling.

    • Defines the initial page size to use for the composite aggregation for each checkpoint. If circuit breaker exceptions occur, the page size is dynamically adjusted to a lower value. The minimum value is 10 and the maximum is 65,536.

    • unattended boolean

      If true, the transform runs in unattended mode. In unattended mode, the transform retries indefinitely in case of an error which means the transform never fails. Setting the number of retries other than infinite fails in validation.

  • sync object

    Additional properties are allowed.

    Hide sync attribute Show sync attribute object
    • time object

      Additional properties are allowed.

      Hide time attributes Show time attributes object
      • delay string

        A duration. Units can be nanos, micros, ms (milliseconds), s (seconds), m (minutes), h (hours) and d (days). Also accepts "0" without a unit and "-1" to indicate an unspecified value.

      • field string Required

        Path to field or array of paths. Some API's support wildcards in the path to select multiple fields.

  • Additional properties are allowed.

    Hide retention_policy attribute Show retention_policy attribute object
    • time object

      Additional properties are allowed.

      Hide time attributes Show time attributes object
      • field string Required

        Path to field or array of paths. Some API's support wildcards in the path to select multiple fields.

      • max_age string Required

        A duration. Units can be nanos, micros, ms (milliseconds), s (seconds), m (minutes), h (hours) and d (days). Also accepts "0" without a unit and "-1" to indicate an unspecified value.

  • latest object

    Additional properties are allowed.

    Hide latest attributes Show latest attributes object
    • sort string Required

      Path to field or array of paths. Some API's support wildcards in the path to select multiple fields.

    • unique_key array[string] Required

      Path to field or array of paths. Some API's support wildcards in the path to select multiple fields.

Responses

  • 200 application/json
    Hide response attributes Show response attributes object
    • generated_dest_index object Required

      Additional properties are allowed.

      Hide generated_dest_index attributes Show generated_dest_index attributes object
      • aliases object
        Hide aliases attribute Show aliases attribute object
      • mappings object

        Additional properties are allowed.

        Hide mappings attributes Show mappings attributes object
      • settings object

        Additional properties are allowed.

        Hide settings attributes Show settings attributes object
        • index object

          Additional properties are allowed.

        • mode string
        • Additional properties are allowed.

          Hide soft_deletes attributes Show soft_deletes attributes object
          • enabled boolean

            Indicates whether soft deletes are enabled on the index.

          • Additional properties are allowed.

            Hide retention_lease attribute Show retention_lease attribute object
            • period string Required

              A duration. Units can be nanos, micros, ms (milliseconds), s (seconds), m (minutes), h (hours) and d (days). Also accepts "0" without a unit and "-1" to indicate an unspecified value.

        • sort object

          Additional properties are allowed.

          Hide sort attributes Show sort attributes object
        • Values are true, false, or checksum.

        • codec string
        • routing_partition_size number | string

          Some APIs will return values such as numbers also as a string (notably epoch timestamps). This behavior is used to capture this behavior while keeping the semantics of the field type.

          Depending on the target language, code generators can keep the union or remove it and leniently parse strings to the target type.

        • merge object

          Additional properties are allowed.

          Hide merge attribute Show merge attribute object
        • A duration. Units can be nanos, micros, ms (milliseconds), s (seconds), m (minutes), h (hours) and d (days). Also accepts "0" without a unit and "-1" to indicate an unspecified value.

        • blocks object

          Additional properties are allowed.

          Hide blocks attributes Show blocks attributes object
        • analyze object

          Additional properties are allowed.

          Hide analyze attribute Show analyze attribute object
        • Additional properties are allowed.

          Hide highlight attribute Show highlight attribute object
        • routing object

          Additional properties are allowed.

          Hide routing attributes Show routing attributes object
          • Additional properties are allowed.

            Hide allocation attributes Show allocation attributes object
            • enable string

              Values are all, primaries, new_primaries, or none.

            • include object

              Additional properties are allowed.

              Hide include attributes Show include attributes object
            • Additional properties are allowed.

              Hide initial_recovery attribute Show initial_recovery attribute object
            • disk object

              Additional properties are allowed.

              Hide disk attribute Show disk attribute object
          • Additional properties are allowed.

            Hide rebalance attribute Show rebalance attribute object
            • enable string Required

              Values are all, primaries, replicas, or none.

        • A duration. Units can be nanos, micros, ms (milliseconds), s (seconds), m (minutes), h (hours) and d (days). Also accepts "0" without a unit and "-1" to indicate an unspecified value.

        • Additional properties are allowed.

          Hide lifecycle attributes Show lifecycle attributes object
          • name string
          • indexing_complete boolean | string

            Some APIs will return values such as numbers also as a string (notably epoch timestamps). This behavior is used to capture this behavior while keeping the semantics of the field type.

            Depending on the target language, code generators can keep the union or remove it and leniently parse strings to the target type.

          • If specified, this is the timestamp used to calculate the index age for its phase transitions. Use this setting if you create a new index that contains old data and want to use the original creation date to calculate the index age. Specified as a Unix epoch value in milliseconds.

          • Set to true to parse the origination date from the index name. This origination date is used to calculate the index age for its phase transitions. The index name must match the pattern .*-{date_format}-\d+, where the date_format is yyyy.MM.dd and the trailing digits are optional. An index that was rolled over would normally match the full format, for example logs-2016.10.31-000002). If the index name doesn’t match the pattern, index creation fails.

          • step object

            Additional properties are allowed.

            Hide step attribute Show step attribute object
            • A duration. Units can be nanos, micros, ms (milliseconds), s (seconds), m (minutes), h (hours) and d (days). Also accepts "0" without a unit and "-1" to indicate an unspecified value.

          • The index alias to update when the index rolls over. Specify when using a policy that contains a rollover action. When the index rolls over, the alias is updated to reflect that the index is no longer the write index. For more information about rolling indices, see Rollover.

        • creation_date number | string

          Some APIs will return values such as numbers also as a string (notably epoch timestamps). This behavior is used to capture this behavior while keeping the semantics of the field type.

          Depending on the target language, code generators can keep the union or remove it and leniently parse strings to the target type.

        • creation_date_string string | number

          A date and time, either as a string whose format can depend on the context (defaulting to ISO 8601), or a number of milliseconds since the Epoch. Elasticsearch accepts both as input, but will generally output a string representation.

        • uuid string
        • version object

          Additional properties are allowed.

          Hide version attributes Show version attributes object
        • translog object

          Additional properties are allowed.

          Hide translog attributes Show translog attributes object
        • Additional properties are allowed.

          Hide query_string attribute Show query_string attribute object
        • analysis object

          Additional properties are allowed.

          Hide analysis attributes Show analysis attributes object
        • settings object

          Additional properties are allowed.

        • Additional properties are allowed.

          Hide time_series attributes Show time_series attributes object
        • queries object

          Additional properties are allowed.

          Hide queries attribute Show queries attribute object
          • cache object

            Additional properties are allowed.

            Hide cache attribute Show cache attribute object
        • Configure custom similarity settings to customize how search results are scored.

        • mapping object

          Additional properties are allowed.

          Hide mapping attributes Show mapping attributes object
          • coerce boolean
          • Additional properties are allowed.

            Hide total_fields attributes Show total_fields attributes object
            • limit number

              The maximum number of fields in an index. Field and object mappings, as well as field aliases count towards this limit. The limit is in place to prevent mappings and searches from becoming too large. Higher values can lead to performance degradations and memory issues, especially in clusters with a high load or few resources.

            • This setting determines what happens when a dynamically mapped field would exceed the total fields limit. When set to false (the default), the index request of the document that tries to add a dynamic field to the mapping will fail with the message Limit of total fields [X] has been exceeded. When set to true, the index request will not fail. Instead, fields that would exceed the limit are not added to the mapping, similar to dynamic: false. The fields that were not added to the mapping will be added to the _ignored field.

          • depth object

            Additional properties are allowed.

            Hide depth attribute Show depth attribute object
            • limit number

              The maximum depth for a field, which is measured as the number of inner objects. For instance, if all fields are defined at the root object level, then the depth is 1. If there is one object mapping, then the depth is 2, etc.

          • Additional properties are allowed.

            Hide nested_fields attribute Show nested_fields attribute object
            • limit number

              The maximum number of distinct nested mappings in an index. The nested type should only be used in special cases, when arrays of objects need to be queried independently of each other. To safeguard against poorly designed mappings, this setting limits the number of unique nested types per index.

          • Additional properties are allowed.

            Hide nested_objects attribute Show nested_objects attribute object
            • limit number

              The maximum number of nested JSON objects that a single document can contain across all nested types. This limit helps to prevent out of memory errors when a document contains too many nested objects.

          • Additional properties are allowed.

            Hide field_name_length attribute Show field_name_length attribute object
            • limit number

              Setting for the maximum length of a field name. This setting isn’t really something that addresses mappings explosion but might still be useful if you want to limit the field length. It usually shouldn’t be necessary to set this setting. The default is okay unless a user starts to add a huge number of fields with really long names. Default is Long.MAX_VALUE (no limit).

          • Additional properties are allowed.

            Hide dimension_fields attribute Show dimension_fields attribute object
            • limit number

              [preview] This functionality is in technical preview and may be changed or removed in a future release. Elastic will work to fix any issues, but features in technical preview are not subject to the support SLA of official GA features.

        • Additional properties are allowed.

          Hide indexing.slowlog attributes Show indexing.slowlog attributes object
          • level string
          • source number
          • reformat boolean
          • Additional properties are allowed.

            Hide threshold attribute Show threshold attribute object
            • index object

              Additional properties are allowed.

              Hide index attributes Show index attributes object
              • warn string

                A duration. Units can be nanos, micros, ms (milliseconds), s (seconds), m (minutes), h (hours) and d (days). Also accepts "0" without a unit and "-1" to indicate an unspecified value.

              • info string

                A duration. Units can be nanos, micros, ms (milliseconds), s (seconds), m (minutes), h (hours) and d (days). Also accepts "0" without a unit and "-1" to indicate an unspecified value.

              • debug string

                A duration. Units can be nanos, micros, ms (milliseconds), s (seconds), m (minutes), h (hours) and d (days). Also accepts "0" without a unit and "-1" to indicate an unspecified value.

              • trace string

                A duration. Units can be nanos, micros, ms (milliseconds), s (seconds), m (minutes), h (hours) and d (days). Also accepts "0" without a unit and "-1" to indicate an unspecified value.

        • Additional properties are allowed.

          Hide indexing_pressure attribute Show indexing_pressure attribute object
          • memory object Required

            Additional properties are allowed.

            Hide memory attribute Show memory attribute object
            • limit number

              Number of outstanding bytes that may be consumed by indexing requests. When this limit is reached or exceeded, the node will reject new coordinating and primary operations. When replica operations consume 1.5x this limit, the node will reject new replica operations. Defaults to 10% of the heap.

        • store object

          Additional properties are allowed.

          Hide store attributes Show store attributes object
          • type string Required

          • allow_mmap boolean

            You can restrict the use of the mmapfs and the related hybridfs store type via the setting node.store.allow_mmap. This is a boolean setting indicating whether or not memory-mapping is allowed. The default is to allow it. This setting is useful, for example, if you are in an environment where you can not control the ability to create a lot of memory maps so you need disable the ability to use memory-mapping.

      • defaults object

        Additional properties are allowed.

        Hide defaults attributes Show defaults attributes object
        • index object

          Additional properties are allowed.

        • mode string
        • Additional properties are allowed.

          Hide soft_deletes attributes Show soft_deletes attributes object
          • enabled boolean

            Indicates whether soft deletes are enabled on the index.

          • Additional properties are allowed.

            Hide retention_lease attribute Show retention_lease attribute object
            • period string Required

              A duration. Units can be nanos, micros, ms (milliseconds), s (seconds), m (minutes), h (hours) and d (days). Also accepts "0" without a unit and "-1" to indicate an unspecified value.

        • sort object

          Additional properties are allowed.

          Hide sort attributes Show sort attributes object
        • Values are true, false, or checksum.

        • codec string
        • routing_partition_size number | string

          Some APIs will return values such as numbers also as a string (notably epoch timestamps). This behavior is used to capture this behavior while keeping the semantics of the field type.

          Depending on the target language, code generators can keep the union or remove it and leniently parse strings to the target type.

        • merge object

          Additional properties are allowed.

          Hide merge attribute Show merge attribute object
        • A duration. Units can be nanos, micros, ms (milliseconds), s (seconds), m (minutes), h (hours) and d (days). Also accepts "0" without a unit and "-1" to indicate an unspecified value.

        • blocks object

          Additional properties are allowed.

          Hide blocks attributes Show blocks attributes object
        • analyze object

          Additional properties are allowed.

          Hide analyze attribute Show analyze attribute object
        • Additional properties are allowed.

          Hide highlight attribute Show highlight attribute object
        • routing object

          Additional properties are allowed.

          Hide routing attributes Show routing attributes object
          • Additional properties are allowed.

            Hide allocation attributes Show allocation attributes object
            • enable string

              Values are all, primaries, new_primaries, or none.

            • include object

              Additional properties are allowed.

              Hide include attributes Show include attributes object
            • Additional properties are allowed.

              Hide initial_recovery attribute Show initial_recovery attribute object
            • disk object

              Additional properties are allowed.

              Hide disk attribute Show disk attribute object
          • Additional properties are allowed.

            Hide rebalance attribute Show rebalance attribute object
            • enable string Required

              Values are all, primaries, replicas, or none.

        • A duration. Units can be nanos, micros, ms (milliseconds), s (seconds), m (minutes), h (hours) and d (days). Also accepts "0" without a unit and "-1" to indicate an unspecified value.

        • Additional properties are allowed.

          Hide lifecycle attributes Show lifecycle attributes object
          • name string
          • indexing_complete boolean | string

            Some APIs will return values such as numbers also as a string (notably epoch timestamps). This behavior is used to capture this behavior while keeping the semantics of the field type.

            Depending on the target language, code generators can keep the union or remove it and leniently parse strings to the target type.

          • If specified, this is the timestamp used to calculate the index age for its phase transitions. Use this setting if you create a new index that contains old data and want to use the original creation date to calculate the index age. Specified as a Unix epoch value in milliseconds.

          • Set to true to parse the origination date from the index name. This origination date is used to calculate the index age for its phase transitions. The index name must match the pattern .*-{date_format}-\d+, where the date_format is yyyy.MM.dd and the trailing digits are optional. An index that was rolled over would normally match the full format, for example logs-2016.10.31-000002). If the index name doesn’t match the pattern, index creation fails.

          • step object

            Additional properties are allowed.

            Hide step attribute Show step attribute object
            • A duration. Units can be nanos, micros, ms (milliseconds), s (seconds), m (minutes), h (hours) and d (days). Also accepts "0" without a unit and "-1" to indicate an unspecified value.

          • The index alias to update when the index rolls over. Specify when using a policy that contains a rollover action. When the index rolls over, the alias is updated to reflect that the index is no longer the write index. For more information about rolling indices, see Rollover.

        • creation_date number | string

          Some APIs will return values such as numbers also as a string (notably epoch timestamps). This behavior is used to capture this behavior while keeping the semantics of the field type.

          Depending on the target language, code generators can keep the union or remove it and leniently parse strings to the target type.

        • creation_date_string string | number

          A date and time, either as a string whose format can depend on the context (defaulting to ISO 8601), or a number of milliseconds since the Epoch. Elasticsearch accepts both as input, but will generally output a string representation.

        • uuid string
        • version object

          Additional properties are allowed.

          Hide version attributes Show version attributes object
        • translog object

          Additional properties are allowed.

          Hide translog attributes Show translog attributes object
        • Additional properties are allowed.

          Hide query_string attribute Show query_string attribute object
        • analysis object

          Additional properties are allowed.

          Hide analysis attributes Show analysis attributes object
        • settings object

          Additional properties are allowed.

        • Additional properties are allowed.

          Hide time_series attributes Show time_series attributes object
        • queries object

          Additional properties are allowed.

          Hide queries attribute Show queries attribute object
          • cache object

            Additional properties are allowed.

            Hide cache attribute Show cache attribute object
        • Configure custom similarity settings to customize how search results are scored.

        • mapping object

          Additional properties are allowed.

          Hide mapping attributes Show mapping attributes object
          • coerce boolean
          • Additional properties are allowed.

            Hide total_fields attributes Show total_fields attributes object
            • limit number

              The maximum number of fields in an index. Field and object mappings, as well as field aliases count towards this limit. The limit is in place to prevent mappings and searches from becoming too large. Higher values can lead to performance degradations and memory issues, especially in clusters with a high load or few resources.

            • This setting determines what happens when a dynamically mapped field would exceed the total fields limit. When set to false (the default), the index request of the document that tries to add a dynamic field to the mapping will fail with the message Limit of total fields [X] has been exceeded. When set to true, the index request will not fail. Instead, fields that would exceed the limit are not added to the mapping, similar to dynamic: false. The fields that were not added to the mapping will be added to the _ignored field.

          • depth object

            Additional properties are allowed.

            Hide depth attribute Show depth attribute object
            • limit number

              The maximum depth for a field, which is measured as the number of inner objects. For instance, if all fields are defined at the root object level, then the depth is 1. If there is one object mapping, then the depth is 2, etc.

          • Additional properties are allowed.

            Hide nested_fields attribute Show nested_fields attribute object
            • limit number

              The maximum number of distinct nested mappings in an index. The nested type should only be used in special cases, when arrays of objects need to be queried independently of each other. To safeguard against poorly designed mappings, this setting limits the number of unique nested types per index.

          • Additional properties are allowed.

            Hide nested_objects attribute Show nested_objects attribute object
            • limit number

              The maximum number of nested JSON objects that a single document can contain across all nested types. This limit helps to prevent out of memory errors when a document contains too many nested objects.

          • Additional properties are allowed.

            Hide field_name_length attribute Show field_name_length attribute object
            • limit number

              Setting for the maximum length of a field name. This setting isn’t really something that addresses mappings explosion but might still be useful if you want to limit the field length. It usually shouldn’t be necessary to set this setting. The default is okay unless a user starts to add a huge number of fields with really long names. Default is Long.MAX_VALUE (no limit).

          • Additional properties are allowed.

            Hide dimension_fields attribute Show dimension_fields attribute object
            • limit number

              [preview] This functionality is in technical preview and may be changed or removed in a future release. Elastic will work to fix any issues, but features in technical preview are not subject to the support SLA of official GA features.

        • Additional properties are allowed.

          Hide indexing.slowlog attributes Show indexing.slowlog attributes object
          • level string
          • source number
          • reformat boolean
          • Additional properties are allowed.

            Hide threshold attribute Show threshold attribute object
            • index object

              Additional properties are allowed.

              Hide index attributes Show index attributes object
              • warn string

                A duration. Units can be nanos, micros, ms (milliseconds), s (seconds), m (minutes), h (hours) and d (days). Also accepts "0" without a unit and "-1" to indicate an unspecified value.

              • info string

                A duration. Units can be nanos, micros, ms (milliseconds), s (seconds), m (minutes), h (hours) and d (days). Also accepts "0" without a unit and "-1" to indicate an unspecified value.

              • debug string

                A duration. Units can be nanos, micros, ms (milliseconds), s (seconds), m (minutes), h (hours) and d (days). Also accepts "0" without a unit and "-1" to indicate an unspecified value.

              • trace string

                A duration. Units can be nanos, micros, ms (milliseconds), s (seconds), m (minutes), h (hours) and d (days). Also accepts "0" without a unit and "-1" to indicate an unspecified value.

        • Additional properties are allowed.

          Hide indexing_pressure attribute Show indexing_pressure attribute object
          • memory object Required

            Additional properties are allowed.

            Hide memory attribute Show memory attribute object
            • limit number

              Number of outstanding bytes that may be consumed by indexing requests. When this limit is reached or exceeded, the node will reject new coordinating and primary operations. When replica operations consume 1.5x this limit, the node will reject new replica operations. Defaults to 10% of the heap.

        • store object

          Additional properties are allowed.

          Hide store attributes Show store attributes object
          • type string Required

          • allow_mmap boolean

            You can restrict the use of the mmapfs and the related hybridfs store type via the setting node.store.allow_mmap. This is a boolean setting indicating whether or not memory-mapping is allowed. The default is to allow it. This setting is useful, for example, if you are in an environment where you can not control the ability to create a lot of memory maps so you need disable the ability to use memory-mapping.

      • Additional properties are allowed.

        Hide lifecycle attributes Show lifecycle attributes object
        • A duration. Units can be nanos, micros, ms (milliseconds), s (seconds), m (minutes), h (hours) and d (days). Also accepts "0" without a unit and "-1" to indicate an unspecified value.

        • Additional properties are allowed.

          Hide downsampling attribute Show downsampling attribute object
          • rounds array[object] Required

            The list of downsampling rounds to execute as part of this downsampling configuration

            Hide rounds attributes Show rounds attributes object
            • after string Required

              A duration. Units can be nanos, micros, ms (milliseconds), s (seconds), m (minutes), h (hours) and d (days). Also accepts "0" without a unit and "-1" to indicate an unspecified value.

            • config object Required

              Additional properties are allowed.

        • enabled boolean

          If defined, it turns data stream lifecycle on/off (true/false) for this data stream. A data stream lifecycle that's disabled (enabled: false) will have no effect on the data stream.

    • preview array[object] Required

      Additional properties are allowed.

GET /_transform/{transform_id}/_preview
curl \
 -X GET http://api.example.com/_transform/{transform_id}/_preview \
 -H "Content-Type: application/json" \
 -d '{"pivot":{"group_by":{"customer_id":{"terms":{"field":"customer_id","missing_bucket":true}}},"aggregations":{"max_price":{"max":{"field":"taxful_total_price"}}}},"source":{"index":"kibana_sample_data_ecommerce"}}'
Request example
{
  "pivot": {
    "group_by": {
      "customer_id": {
        "terms": {
          "field": "customer_id",
          "missing_bucket": true
        }
      }
    },
    "aggregations": {
      "max_price": {
        "max": {
          "field": "taxful_total_price"
        }
      }
    }
  },
  "source": {
    "index": "kibana_sample_data_ecommerce"
  }
}
Response examples (200)
{
  "preview": [
    {
      "max_price": 171,
      "customer_id": "10"
    },
    {
      "max_price": 233,
      "customer_id": "11"
    },
    {
      "max_price": 200,
      "customer_id": "12"
    },
    {
      "max_price": 301,
      "customer_id": "13"
    },
    {
      "max_price": 176,
      "customer_id": "14"
    },
    {
      "max_price": 2250,
      "customer_id": "15"
    },
    {
      "max_price": 170,
      "customer_id": "16"
    },
    {
      "max_price": 243,
      "customer_id": "17"
    },
    {
      "max_price": 154,
      "customer_id": "18"
    },
    {
      "max_price": 393,
      "customer_id": "19"
    },
    {
      "max_price": 165,
      "customer_id": "20"
    },
    {
      "max_price": 115,
      "customer_id": "21"
    },
    {
      "max_price": 192,
      "customer_id": "22"
    },
    {
      "max_price": 169,
      "customer_id": "23"
    },
    {
      "max_price": 230,
      "customer_id": "24"
    },
    {
      "max_price": 278,
      "customer_id": "25"
    },
    {
      "max_price": 200,
      "customer_id": "26"
    },
    {
      "max_price": 344,
      "customer_id": "27"
    },
    {
      "max_price": 175,
      "customer_id": "28"
    },
    {
      "max_price": 177,
      "customer_id": "29"
    },
    {
      "max_price": 190,
      "customer_id": "30"
    },
    {
      "max_price": 190,
      "customer_id": "31"
    },
    {
      "max_price": 205,
      "customer_id": "32"
    },
    {
      "max_price": 215,
      "customer_id": "33"
    },
    {
      "max_price": 270,
      "customer_id": "34"
    },
    {
      "max_price": 184,
      "customer_id": "36"
    },
    {
      "max_price": 222,
      "customer_id": "37"
    },
    {
      "max_price": 370,
      "customer_id": "38"
    },
    {
      "max_price": 240,
      "customer_id": "39"
    },
    {
      "max_price": 230,
      "customer_id": "4"
    },
    {
      "max_price": 229,
      "customer_id": "41"
    },
    {
      "max_price": 190,
      "customer_id": "42"
    },
    {
      "max_price": 150,
      "customer_id": "43"
    },
    {
      "max_price": 175,
      "customer_id": "44"
    },
    {
      "max_price": 190,
      "customer_id": "45"
    },
    {
      "max_price": 150,
      "customer_id": "46"
    },
    {
      "max_price": 310,
      "customer_id": "48"
    },
    {
      "max_price": 223,
      "customer_id": "49"
    },
    {
      "max_price": 283,
      "customer_id": "5"
    },
    {
      "max_price": 185,
      "customer_id": "50"
    },
    {
      "max_price": 190,
      "customer_id": "51"
    },
    {
      "max_price": 333,
      "customer_id": "52"
    },
    {
      "max_price": 165,
      "customer_id": "6"
    },
    {
      "max_price": 144,
      "customer_id": "7"
    },
    {
      "max_price": 198,
      "customer_id": "8"
    },
    {
      "max_price": 210,
      "customer_id": "9"
    }
  ],
  "generated_dest_index": {
    "aliases": {},
    "mappings": {
      "_meta": {
        "_transform": {
          "version": {
            "created": "10.0.0"
          },
          "transform": "transform-preview",
          "creation_date_in_millis": 1712948905889
        },
        "created_by": "transform"
      },
      "properties": {
        "max_price": {
          "type": "half_float"
        },
        "customer_id": {
          "type": "keyword"
        }
      }
    },
    "settings": {
      "index": {
        "number_of_shards": "1",
        "auto_expand_replicas": "0-1"
      }
    }
  }
}