mirror of
https://github.com/GreptimeTeam/greptimedb.git
synced 2026-10-19 02:12:28 +00:00
discord9
981e84caef
A table whose own schema carries a column spelled __name__ cannot be interpreted as PromQL input: the semantic metric name is the table's identity, so a second, ordinary business column of that name would be ambiguous. setup_context() now refuses such tables with ReservedMetricNameColumn (InvalidArguments) at the single selector entry, before any context is filled; legitimately rewritten names from label_join/label_replace/count_values are produced above the selector and never pass through it. With the reserved-name contract, an unmarked physical __name__ column can no longer reach the Prometheus HTTP serializer, so the exported_name auto-rename branch in ColumnLayout::infer is removed and tag names are emitted verbatim. Also narrow column_reference_is_constant to an explicit whitelist of value-preserving plan nodes instead of any single-input passthrough, so a future extension cannot silently waive the dropped-name uniqueness check. Tests that constructed a physical __name__ tag as legal input now assert the entry refusal; the internal __promql_metric_name collision tests are unaffected. Signed-off-by: discord9 <55937128+discord9@users.noreply.github.com>