Metadata Examples and Use Cases

Metadata filters enable highly versatile and granular control over query results. This section provides real-world examples and use cases to illustrate how metadata filters can be applied to solve common business and technical challenges.

Language-specific filtering

In multilingual documents, different sections may be in different languages. Use part-level metadata to target specific language segments.

**Example: **Filter for German-language customer reviews with a rating higher than 3 stars.

LANGUAGE FILTER

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The lang metadata tag used in this example is detected and set automatically by the platform at indexing time. It's set at the part level for accuracy, because a single document may contain content in multiple languages.

Date-specific document retrieval

More complicated expressions are possible, such as the one below, which checks for documents with a publication date in 2021.

Example: Retrieve documents published in 2021 using epoch time.

DATA-SPECIFIC FILTER

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Here, pub_epoch stores the date in epoch time.

You can find a full list of supported operations on the Functions and Operators page, and a full list of how to specify literals on Data Types.

Filter by document status

For auditing purposes, you may want to limit results to documents marked as Published instead of Draft:

doc.status = 'Published'

Filter by custom tag

Custom metadata fields enable filtering based on business-specific criteria, such as priority, category, or internal tags.

Example: Filter documents tagged as High Priority in the Technology category.

BUSINESS-SPECIFIC CRITERIA

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Example query with a document-level filter

This example asks the question "What are the key benefits of cloud computing?" from the Cloud Computing References corpus. Within the corpora object, we specified a metadata_filter to filter though published documents with "metadata_filter": "doc.status = 'Published'",

METADATA EXAMPLE

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Example response with a document-level filter

The example response returns documents with a "status": "Published", in the document metadata. This response also shows other metadata associated with each document_id.

RESPONSE EXAMPLE

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Example query with part-level metadata

Now let's send a query with part-level meta for part.concept = 'Overview'.

We will only change the metadata_filter value from the previous example so that it filters for this part-level metadata:

METADATA EXAMPLE

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Example response with part-level metadata

PART-LEVEL METADATA EXAMPLE

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