ducklake Extension Configuration
The ducklake extension also allows for some configuration regarding retry mechanism for transaction conflicts.
| Name | Description | Default |
|---|---|---|
ducklake_default_data_inlining_row_limit |
Default row limit for data inlining across all connections (0 disables inlining) | 10 |
ducklake_max_retry_count |
The maximum amount of retry attempts for a DuckLake transaction | 10 |
ducklake_retry_backoff |
Backoff factor for exponentially increasing retry wait time | 1.5 |
ducklake_retry_wait_ms |
Time between retries in ms | 100 |
ducklake_write_deletion_vectors |
Experimental. Write Iceberg V3 deletion vectors (puffin) instead of positional delete files (parquet) | false |
Warning Deletion vectors are an experimental feature.
To set these configuration options, use the SET statement:
SET ducklake_default_data_inlining_row_limit = 50;
SET ducklake_max_retry_count = 100;
SET ducklake_retry_backoff = 2;
SET ducklake_retry_wait_ms = 100;
DuckLake-Specific Configuration
DuckLake supports persistent and scoped configuration operations.
These options can be set using the set_option function call.
The options that have been set can be queried using the options function.
Configuration is persisted in the ducklake_metadata table.
DuckLake-Specific Configuration Options
| Name | Description | Default |
|---|---|---|
auto_compact |
Whether a table is included when compaction functions are called without a specific table argument | true |
created_by |
Tool used to write the DuckLake | |
data_inlining_row_limit |
Maximum amount of rows to inline in a single insert | 10 |
data_path |
Path to data files | |
delete_older_than |
How old unused files must be to be removed by cleanup functions | |
encrypted |
Whether or not to encrypt Parquet files written to the data path | false |
expire_older_than |
How old snapshots must be to be expired by default | |
hive_file_pattern |
If partitioned data should be written in a Hive-style folder structure | true |
parquet_compression_level |
Compression level for Parquet files | 3 |
parquet_compression |
Compression algorithm for Parquet files (uncompressed, snappy, gzip, zstd, brotli, lz4, lz4_raw) | snappy |
parquet_row_group_size_bytes |
Number of bytes per row group in Parquet files | |
parquet_row_group_size |
Number of rows per row group in Parquet files | 122880 |
parquet_version |
Parquet format version (1 or 2) | 1 |
per_thread_output |
Whether to create separate output files per thread during parallel insertion | false |
require_commit_message |
If an explicit commit message is required for a snapshot commit | false |
rewrite_delete_threshold |
Minimum fraction of data removed from a file before a rewrite is warranted (0…1) | 0.95 |
sort_on_insert |
Whether to sort data on INSERT according to SET SORTED BY |
true |
target_file_size |
The target data file size for insertion and compaction operations | 512MB |
version |
DuckLake format version | |
write_deletion_vectors |
Experimental. Write Iceberg V3 deletion vectors (puffin) instead of positional delete files (parquet) | false |
Setting DuckLake-Specific Configuration Values
Set the global Parquet compression algorithm used when writing Parquet files:
CALL my_ducklake.set_option('parquet_compression', 'zstd');
Set the Parquet compression algorithm used for tables in a specific schema:
CALL my_ducklake.set_option('parquet_compression', 'zstd', schema => 'my_schema');
Set the Parquet compression algorithm used for a specific table:
CALL my_ducklake.set_option('parquet_compression', 'zstd', table_name => 'my_table');
See all options for the given attached DuckLake
FROM my_ducklake.options();
Scoping
Options can be set either globally, per-schema or per-table. The most specific scope that is set is always used for any given setting, i.e., settings are used in the following priority:
| Priority | Setting Scope |
|---|---|
| 1 | Table |
| 2 | Schema |
| 3 | Global |
| 4 | Default |
DuckLake Instance Settings
The ducklake_settings function returns metadata about a DuckLake instance: the catalog type, the extension version and the data path.
| Column | Description |
|---|---|
catalog_type |
Metadata catalog backend (duckdb, postgres, sqlite) |
extension_version |
Version of the ducklake extension |
data_path |
Path where data files are stored |
FROM ducklake_settings('my_ducklake');
Using the convenience macro on an attached DuckLake:
FROM my_ducklake.settings();