Add docs about map fields #65
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@c-ehrlich This looks great! Thank you so much for writing up the base. |
tothmano
changed the title
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| If you are ingesting tracing data using the [OTLP/HTTP endpoint for traces and logs](/send-data/opentelemetry), you may have noticed that some attributes are moved into the `attributes.custom` map field. | ||
| The benefit of map fields is that you can store additional attributes without adding more fields. This is particularly useful when the shape of your data is unpredictable (for example, additional attributes added by an OpenTelemetry instrumentation). Using map fields means that you can avoid reaching the field limit of a dataset and improve query performance. |
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"by OpenTelemetry instrumentation" sounds more natural i think
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| ```kusto | ||
| ['otel-demo-traces'] | ||
| | where ['attributes.http.url'] == 'http://opentelemetry-demo-frontendproxy:8080/api/cart' |
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this is a string field, not a map (given it's being compared against a string value)
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| [Run in playground](https://play.axiom.co/axiom-play-qf1k/explorer?initForm=%7b%22apl%22%3a%22%5b%27otel-demo-traces%27%5d%5cn%7c%20where%20%5b%27attributes.http.url%27%5d%20%3d%3d%20%27http%3a%2f%2fopentelemetry-demo-frontendproxy%3a8080%2fapi%2fcart%27%22%2c%22queryOptions%22%3a%7b%22quickRange%22%3a%2230d%22%7d%7d) | ||
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| To access `http.protocol` inside the `attributes.custom` map field, use the syntax `['MAP_FIELD_NAME']['INDEX_TO_MAP_FIELD']` instead: |
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the bracketing only needs to happen when there's dots (or other special chars) in the name
if the field is called for example attrs and the property foo, attrs.foo is perfectly valid (but of course ['attrs']['foo'] also works, and so would attrs['foo'] or ['attrs'].foo)
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| Map fields are a special type of field that can hold a collection of nested key-value pairs within a single field. You can think of the content of a map field as a JSON object. | ||
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| ## Benefits of map fields |
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should also mention drawbacks - querying them uses more query gbms, there's no visibility into them from the schema (ie autocomplete will not know what properties are inside the map)
Preview: https://axiom-map-fields-docs.mintlify.app/apl/data-types/map-fields