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OpenSearch:Basic built-in features

Last Updated:Apr 01, 2026

OpenSearch Industry Algorithm Edition provides pre-computed features for use in custom sorting models. These features are automatically derived from your application's search logs and behavioral data, or passed in at query time — no manual computation required.

Feature categories

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Built-in features fall into two categories:

  • Item features: Derived from item properties and historical interaction statistics.

  • User features: Derived from the current user's query context.

Item features

Field features

Field features are derived from the fields in your application schema. All fields are included by default. For each field, select a processing method based on the field type:

  • Text fields: tokenization or vectorization

  • Numeric fields: original value mapping

To use fields that are not in your application schema, import them via a MaxCompute external table.

Processing methods

Each processing method transforms field content differently. The following example uses the input "White T-shirt" to illustrate each method:

Processing methodOutputNotes
Original value mappingWhite T-shirtReturns the raw field value unchanged.
TokenizationWhite^]T-shirtSplits the value into tokens separated by ^].
Generating lookup features after tokenizationWhite:White^]T-shirt:T-shirtProduces token:token pairs, separated by ^].
Counting the number of terms after tokenization2Returns the number of tokens as an integer.
The ^] separator used in tokenization output is the same delimiter used in built-in feature values for fields such as system_query_score_decay and system_qterm_seq_decay. For example: query1:score1^]query2:score2.

Statistical features

Statistical features are computed automatically from your application's search logs and behavioral data. They capture item-level interaction signals — impressions, clicks, and click-through rate (CTR) — over the previous seven days.

Built-in item features

Field nameTypeDescription
system_item_idSTRINGThe unique identifier of the item.
system_all_nid_ctr_30BIGINTThe CTR of the item in the previous 30 days. Discretized.
system_all_nid_ctr_7BIGINTThe CTR of the item in the previous seven days. Discretized.
system_all_nid_ctr_1BIGINTThe CTR of the item within the previous day. Discretized.
system_all_nid_pv_30BIGINTThe number of impressions of the item in the previous 30 days. Discretized.
system_all_nid_pv_7BIGINTThe number of impressions of the item in the previous seven days. Discretized.
system_all_nid_pv_1BIGINTThe number of impressions of the item within the previous day. Discretized.
system_all_nid_ipv_30BIGINTThe number of clicks on the item in the previous 30 days. Discretized.
system_all_nid_ipv_7BIGINTThe number of clicks on the item in the previous seven days. Discretized.
system_all_nid_ipv_1BIGINTThe number of clicks on the item within the previous day. Discretized.
system_query_score_decaySTRINGThe click ratios of the top N queries relevant to the item (default N=20). Format: query1:score1^]query2:score2.
system_qterm_score_decaySTRINGThe click ratios of the top N query terms relevant to the item (default N=300). Format: term1:score1^]term2:score2.
system_query_ctr_decaySTRINGThe CTRs of the top N queries relevant to the item. Format: query1:ctr1^]query2:ctr2.
system_qterm_ctr_decaySTRINGThe CTRs of the top N query terms relevant to the item. Format: term1:ctr1^]term2:ctr2.
system_query_match_decaySTRINGThe search queries and their matches in the top N queries relevant to the item. Format: query1:query1^]query2:query2.
system_qterm_match_decaySTRINGThe search query terms and their matches in the top N query terms relevant to the item. Format: term1:term1^]term2:term2.
system_query_seq_decaySTRINGThe top N queries relevant to the item. Multi-valued feature. Format: query1^]query2.
system_qterm_seq_decaySTRINGThe top N query terms relevant to the item. Multi-valued feature. Format: term1^]term2.
system_query_cntBIGINTThe number of values in system_query_seq_decay.
system_qterm_cntBIGINTThe number of values in system_qterm_seq_decay.
dtSTRINGThe time partition by day. Example: 20230316.

User features

User features capture information about the current user and their query. Two sub-types are available:

  • Query features: Passed via raw_query in the query request. These determine query-related signals such as query tokens and vectorization.

  • User profile features: Imported via a MaxCompute external table for model training. Parameters are passed using the query field during behavior prediction.

User profile features are not supported in OpenSearch.

Built-in user features

Feature nameTypeDescription
system_exp_timeSTRINGThe day of the week on which the behavior occurred. Examples: Monday, Tuesday.
system_terms2STRINGThe first 15 query tokens.
system_user_idSTRINGThe user ID.
system_raw_q_ultraSTRINGThe original query before tokenization.
system_term_seqSTRINGThe sequence feature of the query.
system_term_seq_lengthDOUBLEThe length of the query sequence feature.