Connect to DuckDB + attach a DuckLake catalog

Usage

db_lake_connect(
  duckdb_db = ":memory:",
  catalog = "cso",
  catalog_type = NULL,
  metadata_path = "metadata.ducklake",
  data_path = "//CSO-NAS/DataLake",
  snapshot_version = NULL,
  snapshot_time = NULL,
  threads = NULL,
  memory_limit = NULL,
  load_extensions = NULL
)

Arguments

duckdb_db

DuckDB database file path. Use ":memory:" for in-memory.

catalog

DuckLake catalog name inside DuckDB (e.g. "cso")

catalog_type

Type of catalog database backend. If NULL (default), auto-detected from metadata_path extension:

".sqlite" or ".db" -> "sqlite"
".ducklake" or ".duckdb" -> "duckdb"
"postgres://" connection string -> "postgres"

Can also be set explicitly to one of: "duckdb", "sqlite", "postgres".

metadata_path

Path or connection string for DuckLake metadata:

For "duckdb": file path (e.g. "metadata.ducklake")
For "sqlite": file path (e.g. "//CSO-NAS/DataLake/catalog.sqlite")
For "postgres": connection string (e.g. "dbname=ducklake_catalog host=localhost")

data_path

Root storage path where DuckLake writes Parquet data files

snapshot_version

Optional integer snapshot version to attach at

snapshot_time

Optional timestamp string to attach at (e.g. "2025-05-26 00:00:00")

threads

Number of DuckDB threads (NULL leaves default)

memory_limit

e.g. "4GB" (NULL leaves default)

load_extensions

character vector of extensions to install/load, e.g. c("httpfs")

Value

DuckDB connection object

Examples

if (FALSE) { # \dontrun{
# DuckDB catalog (single user, simplest setup)
db_lake_connect(
  metadata_path = "metadata.ducklake",
  data_path = "//CSO-NAS/DataLake"
)

# SQLite catalog (auto-detected from .sqlite extension)
db_lake_connect(
  metadata_path = "//CSO-NAS/DataLake/catalog.sqlite",
  data_path = "//CSO-NAS/DataLake/data"
)

# PostgreSQL catalog (multi-user lakehouse, remote clients)
db_lake_connect(
  catalog_type = "postgres",
  metadata_path = "dbname=ducklake_catalog host=db.cso.ie user=analyst",
  data_path = "//CSO-NAS/DataLake/data"
)

# Time travel - connect to a specific snapshot
db_lake_connect(
  metadata_path = "catalog.sqlite",
  data_path = "//CSO-NAS/DataLake/data",
  snapshot_version = 5
)
} # }