pgvector/test/t/015_hnsw_duplicates.pl

use strict;
use warnings;
use PostgresNode;
use TestLib;
use Test::More;

# Initialize node
my $node = get_new_node('node');
$node->init;
$node->start;

# Create table
$node->safe_psql("postgres", "CREATE EXTENSION vector;");
$node->safe_psql("postgres", "CREATE TABLE tst (v vector(3));");

sub insert_vectors
{
	for my $i (1 .. 20) {
		$node->safe_psql("postgres", "INSERT INTO tst VALUES ('[1,1,1]')");
	}
}

sub test_duplicates
{
	my $res = $node->safe_psql("postgres", qq(
		SET enable_seqscan = off;
		SET hnsw.ef_search = 1;
		SELECT COUNT(*) FROM (SELECT * FROM tst ORDER BY v <-> '[1,1,1]') t;
	));
	is($res, 10);
}

# Test duplicates with build
insert_vectors();
$node->safe_psql("postgres", "CREATE INDEX idx ON tst USING hnsw (v vector_l2_ops);");
test_duplicates();

# Reset
$node->safe_psql("postgres", "TRUNCATE tst;");

# Test duplicates with inserts
insert_vectors();
test_duplicates();

done_testing();