Method: fhir.search

Full name: projects.locations.datasets.fhirStores.fhir.search

Searches for resources in the given FHIR store according to criteria specified as query parameters.

Implements the FHIR standard search interaction (DSTU2, STU3, R4) using the search semantics described in the FHIR Search specification (DSTU2, STU3, R4).

Supports four methods of search defined by the specification:

• GET [base]?[parameters] to search across all resources.
• GET [base]/[type]?[parameters] to search resources of a specified type.
• POST [base]/_search?[parameters] as an alternate form having the same semantics as the GET method across all resources.
• POST [base]/[type]/_search?[parameters] as an alternate form having the same semantics as the GET method for the specified type.

The GET and POST methods do not support compartment searches. The POST method does not support application/x-www-form-urlencoded search parameters.

On success, the response body contains a JSON-encoded representation of a Bundle resource of type searchset, containing the results of the search. Errors generated by the FHIR store contain a JSON-encoded OperationOutcome resource describing the reason for the error. If the request cannot be mapped to a valid API method on a FHIR store, a generic GCP error might be returned instead.

The server's capability statement, retrieved through capabilities, indicates what search parameters are supported on each FHIR resource. A list of all search parameters defined by the specification can be found in the FHIR Search Parameter Registry (STU3, R4). FHIR search parameters for DSTU2 can be found on each resource's definition page.

Supported search modifiers: :missing, :exact, :contains, :text, :in, :not-in, :above, :below, :[type], :not, and recurse (DSTU2 and STU3) or :iterate (R4).

Supported search result parameters: _sort, _count, _include, _revinclude, _summary=text, _summary=data, and _elements.

The maximum number of search results returned defaults to 100, which can be overridden by the _count parameter up to a maximum limit of 1000. The server might return fewer resources than requested to prevent excessively large responses. If there are additional results, the returned Bundle contains a link of relation "next", which has a _page_token parameter for an opaque pagination token that can be used to retrieve the next page.

Resources with a total size larger than 5MB or a field count larger than 50,000 might not be fully searchable as the server might trim its generated search index in those cases.

Note: FHIR resources are indexed asynchronously, so there might be a slight delay between the time a resource is created or changed, and the time when the change reflects in search results. The only exception is resource identifier data, which is indexed synchronously as a special index. As a result, searching using resource identifier is not subject to indexing delay. To use the special synchronous index, the search term for identifier should be in the pattern identifier=[system]|[value] or identifier=[value], and any of the following search result parameters can be used:

• _count
• _include
• _revinclude
• _summary
• _elements

If your query contains any other search parameters, the standard asynchronous index will be used instead. Note that searching against the special index is optimized for resolving a small number of matches. The search isn't optimized if your identifier search criteria matches a large number (i.e. more than 2,000) of resources. For a search query that will match a large number of resources, you can avoiding using the special synchronous index by including an additional _sort parameter in your query. Use _sort=-_lastUpdated if you want to keep the default sorting order. Note: The special synchronous identifier index are currently disabled for DocumentReference and DocumentManifest searches.

For samples and detailed information, see Searching for FHIR resources and Advanced FHIR search features.