Metadata tables

Every LakeTS metadata object lives in the lakets schema. These tables are the backbone of state management.

_version

Column	Type	Description
version	TEXT	Installed semver (e.g. '0.1.2')
installed_at	TIMESTAMPTZ	Installation timestamp
modules	TEXT[]	List of installed module names

Upgrade guard: prevents downgrade or re-install of the same version.

_chronotable_registry

Column	Type	Description
id	SERIAL	Unique chronotable_id
schema_name	TEXT	Schema name
table_name	TEXT	Table name
time_column	TEXT	Partitioning column
chunk_interval	INTERVAL	Partition size (default 7 days)
space_column	TEXT	Optional secondary (hash) partition column
space_partitions	INT	Number of space partitions (default 1)
tiering_enabled	BOOLEAN	Whether a tiering policy is active
retention_interval	INTERVAL	Retention window, if a policy is set
shadow_table_name	TEXT	lakets_cdf shadow table name when sync is enabled
sync_enabled	BOOLEAN	Whether Lakebase CDF sync is enabled
last_synced_lsn	BIGINT	Last LSN mirrored to the shadow table
created_at	TIMESTAMPTZ	Registration time

_chunk_metadata

Column	Type	Description
id	SERIAL	Unique chunk_id
chronotable_id	INT	FK to _chronotable_registry
chunk_name	TEXT	Partition name
range_start	TIMESTAMPTZ	Lower bound
range_end	TIMESTAMPTZ	Upper bound
status	TEXT	active / tiered / dropped
row_count	BIGINT	Estimated rows in the chunk
size_bytes	BIGINT	Estimated chunk size on disk
tiered_at	TIMESTAMPTZ	When the chunk was flagged tiered (validated durable in UC; partition still resident in Lakebase)
last_write_lsn	PG_LSN	WAL position of the chunk's most recent write (used by the tiering durability gate)
last_modified_at	TIMESTAMPTZ	Last write timestamp (powers chunk-skip pruning)
created_at	TIMESTAMPTZ	Creation time

_rollup_registry

Column	Type	Description
id	SERIAL	Unique rollup_id
name	TEXT	RollUp name (unique)
source_chronotable_id	INT	FK to _chronotable_registry (the source ChronoTable)
rollup_table	TEXT	Materialized RollUp table name (_rollup_{name} in public)
realtime_view	TEXT	Real-time view name, if created
bucket_interval	INTERVAL	Bucket size
refresh_lag	INTERVAL	Minimum time between refreshes (default 1 hour)
watermark	TIMESTAMPTZ	Last refresh boundary
query_text	TEXT	Aggregation SQL
last_refreshed_at	TIMESTAMPTZ	Timestamp of the last successful refresh
bucket_column	TEXT	Auto-detected bucket column (default bucket)
source_time_column	TEXT	Source time column used for predicate injection
predicate_injection	BOOLEAN	Whether incremental refresh injects a time predicate
depends_on	INT[]	Upstream rollup IDs for cascade refresh
sync_enabled	BOOLEAN	Whether Lakebase CDF sync is enabled
shadow_table_name	TEXT	lakets_cdf shadow table name when sync is enabled
created_at	TIMESTAMPTZ	Registration time

_rollup_invalidation_log

Column	Type	Description
id	SERIAL	Unique entry id
rollup_id	INT	FK to _rollup_registry
bucket_start	TIMESTAMPTZ	Dirty bucket timestamp
invalidated_at	TIMESTAMPTZ	When marked dirty

_policy_registry

Column	Type	Description
id	SERIAL	Policy ID
chronotable_id	INT	FK to _chronotable_registry
policy_type	TEXT	tiering / retention / tiered_retention
config	JSONB	Policy parameters
enabled	BOOLEAN	Active flag
last_run_at	TIMESTAMPTZ	Last execution time
created_at	TIMESTAMPTZ	Registration time

_lvc_registry

Column	Type	Description
id	SERIAL	Unique LVC id
chronotable_id	INT	FK to _chronotable_registry
cache_table_name	TEXT	Cache table name (_lvc_{table})
key_columns	TEXT[]	Series-identity columns
value_columns	TEXT[]	Cached value columns
enabled	BOOLEAN	Active flag
created_at	TIMESTAMPTZ	Registration time