Batch INSERT Statements for Bulk Data#
Individual INSERT statements have high overhead. Batch multiple rows in single statements or use COPY.
Incorrect (individual inserts):
-- Each insert is a separate transaction and round trip
insert into events (user_id, action) values (1, 'click');
insert into events (user_id, action) values (1, 'view');
insert into events (user_id, action) values (2, 'click');
-- ... 1000 more individual inserts
-- 1000 inserts = 1000 round trips = slow
Correct (batch insert):
-- Multiple rows in single statement
insert into events (user_id, action) values
(1, 'click'),
(1, 'view'),
(2, 'click'),
-- ... up to ~1000 rows per batch
(999, 'view');
-- One round trip for 1000 rows
For large imports, use COPY:
-- COPY is fastest for bulk loading
copy events (user_id, action, created_at)
from '/path/to/data.csv'
with (format csv, header true);
-- Or from stdin in application
copy events (user_id, action) from stdin with (format csv);
1,click
1,view
2,click
\.
Reference: COPY