[TraceQL] add support for event attribute query

CHANGELOG.md

@@ -6,6 +6,7 @@
 * [CHANGE] Update Go to 1.22.4 [#3757](https://github.com/grafana/tempo/pull/3757) [#3793](https://github.com/grafana/tempo/pull/3793) (@joe-elliott, @mapno)
 * [FEATURE] TraceQL support for link scope and link:traceID and link:spanID [#3741](https://github.com/grafana/tempo/pull/3741) (@stoewer)
 * [FEATURE] TraceQL support for event scope and event:name intrinsic [#3708](https://github.com/grafana/tempo/pull/3708) (@stoewer)
+* [FEATURE] TraecQL support for event attributes [#3708](https://github.com/grafana/tempo/pull/3748) (@ie-pham)
 * [FEATURE] Flush and query RF1 blocks for TraceQL metric queries [#3628](https://github.com/grafana/tempo/pull/3628) [#3691](https://github.com/grafana/tempo/pull/3691) [#3723](https://github.com/grafana/tempo/pull/3723) (@mapno)
 * [FEATURE] Add new compare() metrics function [#3695](https://github.com/grafana/tempo/pull/3695) (@mdisibio)
 * [ENHANCEMENT] Tag value lookup use protobuf internally for improved latency [#3731](https://github.com/grafana/tempo/pull/3731) (@mdisibio)

docs/sources/tempo/traceql/_index.md

@@ -101,7 +101,7 @@ possible to span-level intrinsics.
 
 ### Attribute fields
 
-There are two types of attributes: span attributes and resource attributes. By expanding a span in the Grafana UI, you can see both its span attributes (1 in the screenshot) and resource attributes (2 in the screenshot).
+TraceQL has three different attribute scopes: span attributes, resource attributes, and event attributes. By expanding a span in the Grafana UI, you can see both its span attributes (1 in the screenshot) and resource attributes (2 in the screenshot).
 
 <p align="center"><img src="assets/span-resource-attributes.png" alt="Example of span and resource  attributes." /></p>
 
@@ -128,6 +128,11 @@ Find any database connection string that goes to a Postgres or MySQL database:
 { span.db.system =~ "postgresql|mysql" }
 ```
 
+You can query for an exception in your span event
+```
+{ event.exception.message =~ "something went wrong" }
+```
+
 ### Unscoped attribute fields
 
 Attributes can be unscoped if you are unsure if the requested attribute exists on the span or resource. When possible, use scoped instead of unscoped attributes. Scoped attributes provide faster query results.