Import

Dolt supports three modes of import:

1. LOAD DATA INFILE SQL-server command.

2. dolt table import CLI command.

3. dolt sql < import.sql batch script import.

We recommend (1) > (2) > (3) for large import performance. dolt table import is the most convenient and only slightly slower than LOAD DATA INFILE. Refer to the import tutorial blog for a walkthrough of the different techniques.

Import comparison

Each result row reports the runtime for a MySQL import of a certain table schema (test_name and detail), row count (row_cnt), and sorting (sorting). sql_mult and cli_mult distinguish the Dolt SQL (sql-server LOAD DATA) and CLI (dolt table import) latencies as a multiple of the MySQL latency for the same test conditions. All MySQL tests report the LOAD DATA latency.

We are about 2x slower than MySQL for most import conditions. We are slightly slower importing blobs, reflecting how Dolt chunks blobs individually as prolly trees rather than a single byte array. Both Dolt and MySQL are less efficient importing sql scripts with standalone INSERT rows compared to batched insert script (we have a tool here to batch INSERT scripts).

test_name	detail	row_cnt	sorted	mysql_time	sql_mult	cli_mult
batching	LOAD DATA	10000	1	0.08	0.88
batching	batch sql	10000	1	0.13	1.62
batching	by line sql	10000	1	0.13	1.54
blob	1 blob	200000	1	1.29	3.52	3.78
blob	2 blobs	200000	1	1.29	4.85	4.92
blob	no blob	200000	1	1.3	1.58	1.67
col type	datetime	200000	1	1.21	2.01	2.14
col type	varchar	200000	1	1	2.26	2.44
config width	2 cols	200000	1	1.13	1.51	1.55
config width	32 cols	200000	1	2.61	1.78	2.62
config width	8 cols	200000	1	1.39	1.71	1.95
pk type	float	200000	1	1.28	1.37	1.38
pk type	int	200000	1	1.15	1.47	1.57
pk type	varchar	200000	1	2.22	1.7	1.92
row count	1.6mm	1600000	1	8.02	1.78	1.85
row count	400k	400000	1	2.06	1.66	1.68
row count	800k	800000	1	4.1	1.75	1.79
secondary index	four index	200000	1	5.86	1.29	1.39
secondary index	no secondary	200000	1	1.34	1.46	1.6
secondary index	one index	200000	1	1.73	1.6	1.7
secondary index	two index	200000	1	3.19	1.37	1.46
sorting	shuffled 1mm	1000000	0	8.01	1.86	1.92
sorting	sorted 1mm	1000000	1	8.57	1.71	1.8