how to display Events.Attributes in grafana plugin?

[stchenlucas]

the sql example below shows how to display SpanAttributes and ResourceAttributes in grafana plugin, but how to display Events.Attributes ?

SELECT
    TraceId AS traceID,
    SpanId AS spanID,
    SpanName AS operationName,
    ParentSpanId AS parentSpanID,
    ServiceName AS serviceName,
    Duration / 1000000 AS duration,
    Timestamp AS startTime,
    arrayMap(key -> map('key', key, 'value', SpanAttributes[key]), mapKeys(SpanAttributes)) AS tags,
    arrayMap(key -> map('key', key, 'value', ResourceAttributes[key]), mapKeys(ResourceAttributes)) AS serviceTags
FROM otel.otel_traces
WHERE TraceId = '61d489320c01243966700e172ab37081'
ORDER BY startTime ASC

table definition

CREATE TABLE otel_traces
(
    `Timestamp`         DateTime64(9) CODEC (Delta(8), ZSTD(1)),
    `TraceId`           String CODEC (ZSTD(1)),
    `SpanId`            String CODEC (ZSTD(1)),
    `ParentSpanId`      String CODEC (ZSTD(1)),
    `TraceState`        String CODEC (ZSTD(1)),
    `SpanName` LowCardinality(String) CODEC (ZSTD(1)),
    `SpanKind` LowCardinality(String) CODEC (ZSTD(1)),
    `ServiceName` LowCardinality(String) CODEC (ZSTD(1)),
    `ResourceAttributes` Map(LowCardinality(String), String) CODEC (ZSTD(1)),
    `ScopeName`         String CODEC (ZSTD(1)),
    `ScopeVersion`      String CODEC (ZSTD(1)),
    `SpanAttributes` Map(LowCardinality(String), String) CODEC (ZSTD(1)),
    `Duration`          Int64 CODEC (ZSTD(1)),
    `StatusCode` LowCardinality(String) CODEC (ZSTD(1)),
    `StatusMessage`     String CODEC (ZSTD(1)),
    `Events.Timestamp`  Array(DateTime64(9)) CODEC (ZSTD(1)),
    `Events.Name`       Array(LowCardinality(String)) CODEC (ZSTD(1)),
    `Events.Attributes` Array(Map(LowCardinality(String), String)) CODEC (ZSTD(1)),
    `Links.TraceId`     Array(String) CODEC (ZSTD(1)),
    `Links.SpanId`      Array(String) CODEC (ZSTD(1)),
    `Links.TraceState`  Array(String) CODEC (ZSTD(1)),
    `Links.Attributes`  Array(Map(LowCardinality(String), String)) CODEC (ZSTD(1)),
    INDEX idx_trace_id TraceId TYPE bloom_filter(0.001) GRANULARITY 1,
    INDEX idx_res_attr_key mapKeys(ResourceAttributes) TYPE bloom_filter(0.01) GRANULARITY 1,
    INDEX idx_res_attr_value mapValues(ResourceAttributes) TYPE bloom_filter(0.01) GRANULARITY 1,
    INDEX idx_span_attr_key mapKeys(SpanAttributes) TYPE bloom_filter(0.01) GRANULARITY 1,
    INDEX idx_span_attr_value mapValues(SpanAttributes) TYPE bloom_filter(0.01) GRANULARITY 1,
    INDEX idx_duration Duration TYPE minmax GRANULARITY 1
)
    ENGINE = MergeTree
        PARTITION BY toDate(Timestamp)
        ORDER BY (ServiceName, SpanName, toUnixTimestamp(Timestamp), TraceId)
        TTL toDateTime(Timestamp) + toIntervalDay(3)
        SETTINGS index_granularity = 8192, ttl_only_drop_parts = 1;

[tatchi]

I'm facing the same issue. I think the expected output format is the following (source)

export type TraceKeyValuePair<T = any> = {
  key: string;
  value: T;
  type?: string;
};

/**
 * Type representing a log in a span.
 */
export type TraceLog = {
  // Millisecond epoch time
  timestamp: number;
  fields: TraceKeyValuePair[];
  name?: string;
};

I managed to output an array with name and timestamp

arrayMap(
i -> map(
  'name', Events.Name[i],
  'timestamp', toString(toUnixTimestamp64Milli(Events.Timestamp [i])),
),
arrayEnumerate(Events.Name)
) AS logs

But I cannot figure out how to add the nested attributes array (because a map can only have values of the same type). So the following doesn't work

arrayMap(
i -> map(
  'name', Events.Name[i],
  'timestamp', toString(toUnixTimestamp64Milli(Events.Timestamp [i])),
  'attributes', arrayMap(key -> map('key', key, 'value', Events.Attributes[i][key]), mapKeys(Events.Attributes[i]))
),
arrayEnumerate(Events.Name)
) AS logs

And wrapping the entire arrayMap in toString doesn't work either

[tatchi]

The following works (thanks to @andreypopp for the solution)

SELECT
  arrayMap(
    (name, timestamp, attributes) -> tuple(
      name,
      toString(toUnixTimestamp64Milli(timestamp)),
      arrayMap(
        key -> map('key', key, 'value', attributes[key]),
        mapKeys(attributes)
      )
    )::Tuple(
      name String,
      timestamp String,
      fields Array(Map(String, String))
    ),
    Events.Name,
    Events.Timestamp,
    Events.Attributes
  ) AS logs