Indexes

Ladybug automatically creates a primary key index(hash) on every node table to enforce uniqueness and accelerate primary-key lookups. Ladybug also supports ART indexes for faster range queries on primary keys. Ladybug also maintains zone maps (min/max indexes) on all columns automatically — these are used to skip irrelevant node groups during scans and to answer COUNT(*) queries without reading column data.

Default HASH index

When you create a node table, Ladybug automatically builds a hash-based primary-key index. No extra DDL is required

Space amplification

The hash index stores one entry per node and adds roughly 15–25 bytes per row on top of the column data, depending on the primary key type:

Primary key type	Index overhead
INT32	~14 bytes/row
INT64	~18 bytes/row
STRING	~18 bytes/row + key length

The column data is stored with compression (Zstandard by default) and is typically similar in size to the source Parquet file. So the total on-disk footprint of a node table is roughly:

total size ≈ compressed column data + (num_rows × ~15–25 bytes)

Example: a 300 MB Parquet file resulted in a 1.2 GB .lbdb database with the default hash index enabled. Disabling the hash index brought it down to 1 GB — roughly 16% smaller.

If you want to disable the default HASH index to save space, you can do so by setting the enable_default_hash_index property to false before creating any node tables:

CALL enable_default_hash_index = false;

Note: The config resets on close, so you need to run this command every time you start a new session if you want to keep the default index disabled

Creating indexes manually

If you want to create an index on a node table when the enable_default_hash_index config is set to false, you can run one of the index creation commands:

To create the inbuilt HASH index:

CREATE HASH INDEX <index_name> FOR (<alias>:<NodeTable>) ON (<alias>.<property>);

CREATE INDEX <index_name> FOR (<alias>:<NodeTable>) ON (<alias>.<property>);

To create the ART index:

CREATE ART INDEX <index_name> FOR (<alias>:<NodeTable>) ON (<alias>.<property>);

Note: At a time, only one primary key index can be created per node table