class Aws::CloudSearchDomain::Types::SearchRequest

Container for the parameters to the `Search` request.

@note When making an API call, you may pass SearchRequest

data as a hash:

    {
      cursor: "Cursor",
      expr: "Expr",
      facet: "Facet",
      filter_query: "FilterQuery",
      highlight: "Highlight",
      partial: false,
      query: "Query", # required
      query_options: "QueryOptions",
      query_parser: "simple", # accepts simple, structured, lucene, dismax
      return: "Return",
      size: 1,
      sort: "Sort",
      start: 1,
      stats: "Stat",
    }

@!attribute [rw] cursor

Retrieves a cursor value you can use to page through large result
sets. Use the `size` parameter to control the number of hits to
include in each response. You can specify either the `cursor` or
`start` parameter in a request; they are mutually exclusive. To get
the first cursor, set the cursor value to `initial`. In subsequent
requests, specify the cursor value returned in the hits section of
the response.

For more information, see [Paginating Results][1] in the *Amazon
CloudSearch Developer Guide*.

[1]: http://docs.aws.amazon.com/cloudsearch/latest/developerguide/paginating-results.html
@return [String]

@!attribute [rw] expr

Defines one or more numeric expressions that can be used to sort
results or specify search or filter criteria. You can also specify
expressions as return fields.

You specify the expressions in JSON using the form
`\{"EXPRESSIONNAME":"EXPRESSION"\}`. You can define and use multiple
expressions in a search request. For example:

` \{"expression1":"_score*rating", "expression2":"(1/rank)*year"\} `

For information about the variables, operators, and functions you
can use in expressions, see [Writing Expressions][1] in the *Amazon
CloudSearch Developer Guide*.

[1]: http://docs.aws.amazon.com/cloudsearch/latest/developerguide/configuring-expressions.html#writing-expressions
@return [String]

@!attribute [rw] facet

Specifies one or more fields for which to get facet information, and
options that control how the facet information is returned. Each
specified field must be facet-enabled in the domain configuration.
The fields and options are specified in JSON using the form
`\{"FIELD":\{"OPTION":VALUE,"OPTION:"STRING"\},"FIELD":\{"OPTION":VALUE,"OPTION":"STRING"\}\}`.

You can specify the following faceting options:

* `buckets` specifies an array of the facet values or ranges to
  count. Ranges are specified using the same syntax that you use to
  search for a range of values. For more information, see [
  Searching for a Range of Values][1] in the *Amazon CloudSearch
  Developer Guide*. Buckets are returned in the order they are
  specified in the request. The `sort` and `size` options are not
  valid if you specify `buckets`.

* `size` specifies the maximum number of facets to include in the
  results. By default, Amazon CloudSearch returns counts for the top
  10. The `size` parameter is only valid when you specify the `sort`
  option; it cannot be used in conjunction with `buckets`.

* `sort` specifies how you want to sort the facets in the results:
  `bucket` or `count`. Specify `bucket` to sort alphabetically or
  numerically by facet value (in ascending order). Specify `count`
  to sort by the facet counts computed for each facet value (in
  descending order). To retrieve facet counts for particular values
  or ranges of values, use the `buckets` option instead of `sort`.

If no facet options are specified, facet counts are computed for all
field values, the facets are sorted by facet count, and the top 10
facets are returned in the results.

To count particular buckets of values, use the `buckets` option. For
example, the following request uses the `buckets` option to
calculate and return facet counts by decade.

`
\{"year":\{"buckets":["[1970,1979]","[1980,1989]","[1990,1999]","[2000,2009]","[2010,\}"]\}\}
`

To sort facets by facet count, use the `count` option. For example,
the following request sets the `sort` option to `count` to sort the
facet values by facet count, with the facet values that have the
most matching documents listed first. Setting the `size` option to 3
returns only the top three facet values.

` \{"year":\{"sort":"count","size":3\}\} `

To sort the facets by value, use the `bucket` option. For example,
the following request sets the `sort` option to `bucket` to sort the
facet values numerically by year, with earliest year listed first.

` \{"year":\{"sort":"bucket"\}\} `

For more information, see [Getting and Using Facet Information][2]
in the *Amazon CloudSearch Developer Guide*.

[1]: http://docs.aws.amazon.com/cloudsearch/latest/developerguide/searching-ranges.html
[2]: http://docs.aws.amazon.com/cloudsearch/latest/developerguide/faceting.html
@return [String]

@!attribute [rw] filter_query

Specifies a structured query that filters the results of a search
without affecting how the results are scored and sorted. You use
`filterQuery` in conjunction with the `query` parameter to filter
the documents that match the constraints specified in the `query`
parameter. Specifying a filter controls only which matching
documents are included in the results, it has no effect on how they
are scored and sorted. The `filterQuery` parameter supports the full
structured query syntax.

For more information about using filters, see [Filtering Matching
Documents][1] in the *Amazon CloudSearch Developer Guide*.

[1]: http://docs.aws.amazon.com/cloudsearch/latest/developerguide/filtering-results.html
@return [String]

@!attribute [rw] highlight

Retrieves highlights for matches in the specified `text` or
`text-array` fields. Each specified field must be highlight enabled
in the domain configuration. The fields and options are specified in
JSON using the form
`\{"FIELD":\{"OPTION":VALUE,"OPTION:"STRING"\},"FIELD":\{"OPTION":VALUE,"OPTION":"STRING"\}\}`.

You can specify the following highlight options:

* `format`\: specifies the format of the data in the text field:
  `text` or `html`. When data is returned as HTML, all
  non-alphanumeric characters are encoded. The default is `html`.
* `max_phrases`\: specifies the maximum number of occurrences of the
  search term(s) you want to highlight. By default, the first
  occurrence is highlighted.
* `pre_tag`\: specifies the string to prepend to an occurrence of a
  search term. The default for HTML highlights is `<em>`. The
  default for text highlights is `*`.
* `post_tag`\: specifies the string to append to an occurrence of a
  search term. The default for HTML highlights is `</em>`. The
  default for text highlights is `*`.

If no highlight options are specified for a field, the returned
field text is treated as HTML and the first match is highlighted
with emphasis tags: `<em>search-term</em>`.

For example, the following request retrieves highlights for the
`actors` and `title` fields.

`\{ "actors": \{\}, "title": \{"format": "text","max_phrases":
2,"pre_tag": "","post_tag": ""\} \}`
@return [String]

@!attribute [rw] partial

Enables partial results to be returned if one or more index
partitions are unavailable. When your search index is partitioned
across multiple search instances, by default Amazon CloudSearch only
returns results if every partition can be queried. This means that
the failure of a single search instance can result in 5xx (internal
server) errors. When you enable partial results, Amazon CloudSearch
returns whatever results are available and includes the percentage
of documents searched in the search results (percent-searched). This
enables you to more gracefully degrade your users' search
experience. For example, rather than displaying no results, you
could display the partial results and a message indicating that the
results might be incomplete due to a temporary system outage.
@return [Boolean]

@!attribute [rw] query

Specifies the search criteria for the request. How you specify the
search criteria depends on the query parser used for the request and
the parser options specified in the `queryOptions` parameter. By
default, the `simple` query parser is used to process requests. To
use the `structured`, `lucene`, or `dismax` query parser, you must
also specify the `queryParser` parameter.

For more information about specifying search criteria, see
[Searching Your Data][1] in the *Amazon CloudSearch Developer
Guide*.

[1]: http://docs.aws.amazon.com/cloudsearch/latest/developerguide/searching.html
@return [String]

@!attribute [rw] query_options

Configures options for the query parser specified in the
`queryParser` parameter. You specify the options in JSON using the
following form
`\{"OPTION1":"VALUE1","OPTION2":VALUE2"..."OPTIONN":"VALUEN"\}.`

The options you can configure vary according to which parser you
use:

* `defaultOperator`\: The default operator used to combine
  individual terms in the search string. For example:
  `defaultOperator: 'or'`. For the `dismax` parser, you specify a
  percentage that represents the percentage of terms in the search
  string (rounded down) that must match, rather than a default
  operator. A value of `0%` is the equivalent to OR, and a value of
  `100%` is equivalent to AND. The percentage must be specified as a
  value in the range 0-100 followed by the percent (%) symbol. For
  example, `defaultOperator: 50%`. Valid values: `and`, `or`, a
  percentage in the range 0%-100% (`dismax`). Default: `and`
  (`simple`, `structured`, `lucene`) or `100` (`dismax`). Valid for:
  `simple`, `structured`, `lucene`, and `dismax`.
* `fields`\: An array of the fields to search when no fields are
  specified in a search. If no fields are specified in a search and
  this option is not specified, all text and text-array fields are
  searched. You can specify a weight for each field to control the
  relative importance of each field when Amazon CloudSearch
  calculates relevance scores. To specify a field weight, append a
  caret (`^`) symbol and the weight to the field name. For example,
  to boost the importance of the `title` field over the
  `description` field you could specify:
  `"fields":["title^5","description"]`. Valid values: The name of
  any configured field and an optional numeric value greater than
  zero. Default: All `text` and `text-array` fields. Valid for:
  `simple`, `structured`, `lucene`, and `dismax`.
* `operators`\: An array of the operators or special characters you
  want to disable for the simple query parser. If you disable the
  `and`, `or`, or `not` operators, the corresponding operators (`+`,
  `|`, `-`) have no special meaning and are dropped from the search
  string. Similarly, disabling `prefix` disables the wildcard
  operator (`*`) and disabling `phrase` disables the ability to
  search for phrases by enclosing phrases in double quotes.
  Disabling precedence disables the ability to control order of
  precedence using parentheses. Disabling `near` disables the
  ability to use the ~ operator to perform a sloppy phrase search.
  Disabling the `fuzzy` operator disables the ability to use the ~
  operator to perform a fuzzy search. `escape` disables the ability
  to use a backslash (``) to escape special characters within the
  search string. Disabling whitespace is an advanced option that
  prevents the parser from tokenizing on whitespace, which can be
  useful for Vietnamese. (It prevents Vietnamese words from being
  split incorrectly.) For example, you could disable all operators
  other than the phrase operator to support just simple term and
  phrase queries: `"operators":["and","not","or", "prefix"]`. Valid
  values: `and`, `escape`, `fuzzy`, `near`, `not`, `or`, `phrase`,
  `precedence`, `prefix`, `whitespace`. Default: All operators and
  special characters are enabled. Valid for: `simple`.
* `phraseFields`\: An array of the `text` or `text-array` fields you
  want to use for phrase searches. When the terms in the search
  string appear in close proximity within a field, the field scores
  higher. You can specify a weight for each field to boost that
  score. The `phraseSlop` option controls how much the matches can
  deviate from the search string and still be boosted. To specify a
  field weight, append a caret (`^`) symbol and the weight to the
  field name. For example, to boost phrase matches in the `title`
  field over the `abstract` field, you could specify:
  `"phraseFields":["title^3", "plot"]` Valid values: The name of any
  `text` or `text-array` field and an optional numeric value greater
  than zero. Default: No fields. If you don't specify any fields
  with `phraseFields`, proximity scoring is disabled even if
  `phraseSlop` is specified. Valid for: `dismax`.
* `phraseSlop`\: An integer value that specifies how much matches
  can deviate from the search phrase and still be boosted according
  to the weights specified in the `phraseFields` option; for
  example, `phraseSlop: 2`. You must also specify `phraseFields` to
  enable proximity scoring. Valid values: positive integers.
  Default: 0. Valid for: `dismax`.
* `explicitPhraseSlop`\: An integer value that specifies how much a
  match can deviate from the search phrase when the phrase is
  enclosed in double quotes in the search string. (Phrases that
  exceed this proximity distance are not considered a match.) For
  example, to specify a slop of three for dismax phrase queries, you
  would specify `"explicitPhraseSlop":3`. Valid values: positive
  integers. Default: 0. Valid for: `dismax`.
* `tieBreaker`\: When a term in the search string is found in a
  document's field, a score is calculated for that field based on
  how common the word is in that field compared to other documents.
  If the term occurs in multiple fields within a document, by
  default only the highest scoring field contributes to the
  document's overall score. You can specify a `tieBreaker` value to
  enable the matches in lower-scoring fields to contribute to the
  document's score. That way, if two documents have the same max
  field score for a particular term, the score for the document that
  has matches in more fields will be higher. The formula for
  calculating the score with a tieBreaker is `(max field score) +
  (tieBreaker) * (sum of the scores for the rest of the matching
  fields)`. Set `tieBreaker` to 0 to disregard all but the highest
  scoring field (pure max): `"tieBreaker":0`. Set to 1 to sum the
  scores from all fields (pure sum): `"tieBreaker":1`. Valid values:
  0.0 to 1.0. Default: 0.0. Valid for: `dismax`.
@return [String]

@!attribute [rw] query_parser

Specifies which query parser to use to process the request. If
`queryParser` is not specified, Amazon CloudSearch uses the `simple`
query parser.

Amazon CloudSearch supports four query parsers:

* `simple`\: perform simple searches of `text` and `text-array`
  fields. By default, the `simple` query parser searches all `text`
  and `text-array` fields. You can specify which fields to search by
  with the `queryOptions` parameter. If you prefix a search term
  with a plus sign (+) documents must contain the term to be
  considered a match. (This is the default, unless you configure the
  default operator with the `queryOptions` parameter.) You can use
  the `-` (NOT), `|` (OR), and `*` (wildcard) operators to exclude
  particular terms, find results that match any of the specified
  terms, or search for a prefix. To search for a phrase rather than
  individual terms, enclose the phrase in double quotes. For more
  information, see [Searching for Text][1] in the *Amazon
  CloudSearch Developer Guide*.
* `structured`\: perform advanced searches by combining multiple
  expressions to define the search criteria. You can also search
  within particular fields, search for values and ranges of values,
  and use advanced options such as term boosting, `matchall`, and
  `near`. For more information, see [Constructing Compound
  Queries][2] in the *Amazon CloudSearch Developer Guide*.
* `lucene`\: search using the Apache Lucene query parser syntax. For
  more information, see [Apache Lucene Query Parser Syntax][3].
* `dismax`\: search using the simplified subset of the Apache Lucene
  query parser syntax defined by the DisMax query parser. For more
  information, see [DisMax Query Parser Syntax][4].

[1]: http://docs.aws.amazon.com/cloudsearch/latest/developerguide/searching-text.html
[2]: http://docs.aws.amazon.com/cloudsearch/latest/developerguide/searching-compound-queries.html
[3]: http://lucene.apache.org/core/4_6_0/queryparser/org/apache/lucene/queryparser/classic/package-summary.html#package_description
[4]: http://wiki.apache.org/solr/DisMaxQParserPlugin#Query_Syntax
@return [String]

@!attribute [rw] return

Specifies the field and expression values to include in the
response. Multiple fields or expressions are specified as a
comma-separated list. By default, a search response includes all
return enabled fields (`_all_fields`). To return only the document
IDs for the matching documents, specify `_no_fields`. To retrieve
the relevance score calculated for each document, specify `_score`.
@return [String]

@!attribute [rw] size

Specifies the maximum number of search hits to include in the
response.
@return [Integer]

@!attribute [rw] sort

Specifies the fields or custom expressions to use to sort the search
results. Multiple fields or expressions are specified as a
comma-separated list. You must specify the sort direction (`asc` or
`desc`) for each field; for example, `year desc,title asc`. To use a
field to sort results, the field must be sort-enabled in the domain
configuration. Array type fields cannot be used for sorting. If no
`sort` parameter is specified, results are sorted by their default
relevance scores in descending order: `_score desc`. You can also
sort by document ID (`_id asc`) and version (`_version desc`).

For more information, see [Sorting Results][1] in the *Amazon
CloudSearch Developer Guide*.

[1]: http://docs.aws.amazon.com/cloudsearch/latest/developerguide/sorting-results.html
@return [String]

@!attribute [rw] start

Specifies the offset of the first search hit you want to return.
Note that the result set is zero-based; the first result is at index
0. You can specify either the `start` or `cursor` parameter in a
request, they are mutually exclusive.

For more information, see [Paginating Results][1] in the *Amazon
CloudSearch Developer Guide*.

[1]: http://docs.aws.amazon.com/cloudsearch/latest/developerguide/paginating-results.html
@return [Integer]

@!attribute [rw] stats

Specifies one or more fields for which to get statistics
information. Each specified field must be facet-enabled in the
domain configuration. The fields are specified in JSON using the
form:

 `\{"FIELD-A":\{\},"FIELD-B":\{\}\}` There are currently no options supported for statistics.
@return [String]

Constants

SENSITIVE