perf(clickhouse): add task_events_v2 trace_id bloom-filter skip index

Mono-RevId: 507cf22bb577a9a495820c9028bc7cd7a0c7fede

Author: Mariefay

internal-packages/clickhouse/schema/047_add_task_events_v2_trace_id_index.sql

@@ -0,0 +1,13 @@
+-- +goose Up
+-- Bloom-filter skip index on trace_id (the trailing ORDER BY column) so a
+-- single-trace read prunes to the trace's footprint, matching the existing
+-- run_id / span_id indexes. Metadata-only: ADD INDEX covers new parts only (no
+-- MATERIALIZE), so existing parts stay indexed only once they merge or age out
+-- under retention -- coverage ramps in, it is not immediate. See the PR for the
+-- rollout-window details.
+ALTER TABLE trigger_dev.task_events_v2
+  ADD INDEX IF NOT EXISTS idx_trace_id trace_id TYPE bloom_filter(0.001) GRANULARITY 1;
+
+-- +goose Down
+ALTER TABLE trigger_dev.task_events_v2
+  DROP INDEX IF EXISTS idx_trace_id;