From 8e979ed37760b1b73e32fa149c27449bf2169da8 Mon Sep 17 00:00:00 2001
From: Andrew Kane <andrew@ankane.org>
Date: Wed, 25 Sep 2024 13:48:24 -0700
Subject: [PATCH] Do not adjust index selectivity based on probes [skip ci]

---
 src/ivfflat.c                   | 7 -------
 test/t/009_ivfflat_filtering.pl | 6 ++----
 2 files changed, 2 insertions(+), 11 deletions(-)

diff --git a/src/ivfflat.c b/src/ivfflat.c
index 4e9b9a4..986e19d 100644
--- a/src/ivfflat.c
+++ b/src/ivfflat.c
@@ -120,13 +120,6 @@ ivfflatcostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
 		costs.indexTotalCost -= 0.5 * costs.numIndexPages * (costs.spc_random_page_cost - spc_seq_page_cost);
 	}
 
-	/*
-	 * If the list selectivity is lower than what is returned from the generic
-	 * cost estimator, use that.
-	 */
-	if (ratio < costs.indexSelectivity)
-		costs.indexSelectivity = ratio;
-
 	/* Use total cost since most work happens before first tuple is returned */
 	*indexStartupCost = costs.indexTotalCost;
 	*indexTotalCost = costs.indexTotalCost;
diff --git a/test/t/009_ivfflat_filtering.pl b/test/t/009_ivfflat_filtering.pl
index efe0866..72b2c53 100644
--- a/test/t/009_ivfflat_filtering.pl
+++ b/test/t/009_ivfflat_filtering.pl
@@ -94,8 +94,7 @@ like($explain, qr/Seq Scan/);
 $explain = $node->safe_psql("postgres", qq(
 	EXPLAIN ANALYZE SELECT i FROM tst WHERE v <-> '$query' < 1 ORDER BY v <-> '$query';
 ));
-# TODO Do not use index
-like($explain, qr/Index Scan using idx/);
+like($explain, qr/Seq Scan/);
 
 # Test attribute index
 $node->safe_psql("postgres", "CREATE INDEX attribute_idx ON tst (c);");
@@ -110,7 +109,6 @@ $node->safe_psql("postgres", "CREATE INDEX partial_idx ON tst USING ivfflat (v v
 $explain = $node->safe_psql("postgres", qq(
 	EXPLAIN ANALYZE SELECT i FROM tst WHERE c = $c ORDER BY v <-> '$query' LIMIT $limit;
 ));
-# TODO Use partial index
-like($explain, qr/Index Scan using idx/);
+like($explain, qr/Index Scan using partial_idx/);
 
 done_testing();