Updated range and defaults for iterative search parameters

src/hnsw.c

@@ -84,8 +84,8 @@ HnswInit(void)
 
 	/* This is approximate and does not apply to the initial scan */
 	DefineCustomIntVariable("hnsw.max_search_tuples", "Sets the max number of candidates to visit for iterative search",
-							"-1 means no limit", &hnsw_max_search_tuples,
+							NULL, &hnsw_max_search_tuples,
-							-1, -1, INT_MAX, PGC_USERSET, 0, NULL, NULL, NULL);
+							20000, 1, INT_MAX, PGC_USERSET, 0, NULL, NULL, NULL);
 
 	MarkGUCPrefixReserved("hnsw");
 }

src/hnswscan.c

@@ -241,7 +241,7 @@ hnswgettuple(IndexScanDesc scan, ScanDirection dir)
 				break;
 
 			/* Reached max number of tuples */
-			if (hnsw_max_search_tuples != -1 && so->tuples >= hnsw_max_search_tuples)
+			if (so->tuples >= hnsw_max_search_tuples)
 			{
 				if (pairingheap_is_empty(so->discarded))
 					break;

src/ivfflat.c

@@ -47,8 +47,8 @@ IvfflatInit(void)
 
 	/* If this is less than probes, probes is used */
 	DefineCustomIntVariable("ivfflat.max_probes", "Sets the max number of probes for iterative search",
-							"-1 means no limit", &ivfflat_max_probes,
+							NULL, &ivfflat_max_probes,
-							-1, -1, IVFFLAT_MAX_LISTS, PGC_USERSET, 0, NULL, NULL, NULL);
+							IVFFLAT_MAX_LISTS, IVFFLAT_MIN_LISTS, IVFFLAT_MAX_LISTS, PGC_USERSET, 0, NULL, NULL, NULL);
 
 	MarkGUCPrefixReserved("ivfflat");
 }

src/ivfscan.c

@@ -264,17 +264,7 @@ ivfflatbeginscan(Relation index, int nkeys, int norderbys)
 	IvfflatGetMetaPageInfo(index, &lists, &dimensions);
 
 	if (ivfflat_iterative_search != IVFFLAT_ITERATIVE_SEARCH_OFF)
-	{
+		maxProbes = Max(ivfflat_max_probes, probes);
-		maxProbes = ivfflat_max_probes;
-
-		if (maxProbes < 0)
-			maxProbes = lists;
-		else if (maxProbes < probes)
-		{
-			/* TODO Show notice */
-			maxProbes = probes;
-		}
-	}
 	else
 		maxProbes = probes;
 

test/expected/hnsw_vector.out

@@ -177,9 +177,9 @@ HINT:  Available values: off, relaxed_order, strict_order.
 SHOW hnsw.max_search_tuples;
  hnsw.max_search_tuples 
 ------------------------
- -1
+ 20000
 (1 row)
 
-SET hnsw.max_search_tuples = -2;
+SET hnsw.max_search_tuples = 0;
-ERROR:  -2 is outside the valid range for parameter "hnsw.max_search_tuples" (-1 .. 2147483647)
+ERROR:  0 is outside the valid range for parameter "hnsw.max_search_tuples" (1 .. 2147483647)
 DROP TABLE t;

test/expected/ivfflat_vector.out

@@ -95,13 +95,6 @@ SELECT * FROM t ORDER BY val <-> '[3,3,3]';
  [0,0,0]
 (3 rows)
 
-SET ivfflat.max_probes = 0;
-SELECT * FROM t ORDER BY val <-> '[3,3,3]';
-   val   
----------
- [1,2,3]
-(1 row)
-
 SET ivfflat.max_probes = 1;
 SELECT * FROM t ORDER BY val <-> '[3,3,3]';
    val   
@@ -163,11 +156,11 @@ HINT:  Available values: off, relaxed_order.
 SHOW ivfflat.max_probes;
  ivfflat.max_probes 
 --------------------
- -1
+ 32768
 (1 row)
 
-SET ivfflat.max_probes = -2;
+SET ivfflat.max_probes = 0;
-ERROR:  -2 is outside the valid range for parameter "ivfflat.max_probes" (-1 .. 32768)
+ERROR:  0 is outside the valid range for parameter "ivfflat.max_probes" (1 .. 32768)
 SET ivfflat.max_probes = 32769;
-ERROR:  32769 is outside the valid range for parameter "ivfflat.max_probes" (-1 .. 32768)
+ERROR:  32769 is outside the valid range for parameter "ivfflat.max_probes" (1 .. 32768)
 DROP TABLE t;

test/sql/hnsw_vector.sql

@@ -104,6 +104,6 @@ SET hnsw.iterative_search = on;
 
 SHOW hnsw.max_search_tuples;
 
-SET hnsw.max_search_tuples = -2;
+SET hnsw.max_search_tuples = 0;
 
 DROP TABLE t;

test/sql/ivfflat_vector.sql

@@ -53,9 +53,6 @@ CREATE INDEX ON t USING ivfflat (val vector_l2_ops) WITH (lists = 3);
 SET ivfflat.iterative_search = relaxed_order;
 SELECT * FROM t ORDER BY val <-> '[3,3,3]';
 
-SET ivfflat.max_probes = 0;
-SELECT * FROM t ORDER BY val <-> '[3,3,3]';
-
 SET ivfflat.max_probes = 1;
 SELECT * FROM t ORDER BY val <-> '[3,3,3]';
 
@@ -93,7 +90,7 @@ SET ivfflat.iterative_search = on;
 
 SHOW ivfflat.max_probes;
 
-SET ivfflat.max_probes = -2;
+SET ivfflat.max_probes = 0;
 SET ivfflat.max_probes = 32769;
 
 DROP TABLE t;

test/t/043_hnsw_iterative_search.pl

@@ -27,6 +27,7 @@ $node->safe_psql("postgres", qq(
 my $count = $node->safe_psql("postgres", qq(
 	SET enable_seqscan = off;
 	SET hnsw.iterative_search = relaxed_order;
+	SET hnsw.max_search_tuples = 100000;
 	SET work_mem = '8MB';
 	SELECT COUNT(*) FROM (SELECT v FROM tst WHERE i % 10000 = 0 ORDER BY v <-> (SELECT v FROM tst LIMIT 1) LIMIT 11) t;
 ));
@@ -59,7 +60,7 @@ my ($ret, $stdout, $stderr) = $node->psql("postgres", qq(
 	SET enable_seqscan = off;
 	SET hnsw.iterative_search = relaxed_order;
 	SET client_min_messages = debug1;
-	SET work_mem = '2MB';
+	SET work_mem = '1MB';
 	SELECT COUNT(*) FROM (SELECT v FROM tst WHERE i % 10000 = 0 ORDER BY v <-> (SELECT v FROM tst LIMIT 1) LIMIT 11) t;
 ));
 like($stderr, qr/hnsw index scan exceeded work_mem after \d+ tuples/);