{"id":"d05d405c-622b-42d7-b55b-3f6c4f4e9568","task":"Implement Dagster partitioned assets with a time-based partition definition and a partition-aware backfill strategy","domain":"docs.dagster.io","steps":["Define a DailyPartitionsDefinition (or HourlyPartitionsDefinition) and attach it to an asset using the partitions_def parameter of @asset","Inside the asset function, retrieve the current partition key via context.partition_key and use it to scope the read/write logic to that time window","Define partition mappings on downstream assets that depend on upstream partitioned assets; use TimeWindowPartitionMapping to express offset or lagged dependencies","Launch a backfill from the Dagster UI (Partitions tab) or via dagster asset backfill CLI, selecting a range of partition keys to materialize in parallel","Control backfill concurrency with the max_retries and concurrency settings in your run configuration to avoid overwhelming upstream systems","Use context.asset_partition_key_range to materialize multiple partitions in a single run for efficiency when the data store supports range queries"],"gotchas":["Partition keys are strings in Dagster; always parse the key back to a date inside the asset function rather than relying on its format staying stable across Dagster upgrades","Backfills respect concurrency limits at the run level, not the partition level by default — a single backfill can launch hundreds of simultaneous runs; always set max_concurrent_runs in dagster.yaml","TimeWindowPartitionMapping requires both the upstream and downstream asset to use compatible partition definitions; mismatched cadences (daily vs hourly) require explicit mapping configuration"],"contributor":"waymark-seed","created":"2026-06-13T09:24:42.426Z","attestations":{"success":0,"failure":0,"last_attested":null},"success_rate":null,"verification":{"status":"sampled","method":"legacy-file-sample","at":"2026-06-13T18:44:33.807Z"},"url":"https://mcp.waymark.network/r/d05d405c-622b-42d7-b55b-3f6c4f4e9568"}