Use -1 for no limit for ivfflat.max_probes [skip ci]

src/hnsw.c

@@ -82,7 +82,6 @@ HnswInit(void)
 							 NULL, &hnsw_iterative_search,
 							 HNSW_ITERATIVE_SEARCH_OFF, hnsw_iterative_search_options, PGC_USERSET, 0, NULL, NULL, NULL);
 
-	/* TODO Ensure ivfflat.max_probes uses same value for no limit */
 	DefineCustomIntVariable("hnsw.max_search_tuples", "Sets the max number of candidates to visit for iterative search",
 							"-1 means no limit", &hnsw_max_search_tuples,
 							-1, -1, INT_MAX, PGC_USERSET, 0, NULL, NULL, NULL);

src/ivfflat.c

@@ -46,8 +46,8 @@ IvfflatInit(void)
 							 IVFFLAT_ITERATIVE_SEARCH_OFF, ivfflat_iterative_search_options, PGC_USERSET, 0, NULL, NULL, NULL);
 
 	DefineCustomIntVariable("ivfflat.max_probes", "Sets the max number of probes for iterative search",
-							"Zero sets to the number of lists", &ivfflat_max_probes,
-							0, 0, IVFFLAT_MAX_LISTS, PGC_USERSET, 0, NULL, NULL, NULL);
+							"-1 means no limit", &ivfflat_max_probes,
+							-1, -1, IVFFLAT_MAX_LISTS, PGC_USERSET, 0, NULL, NULL, NULL);
 
 	MarkGUCPrefixReserved("ivfflat");
 }

src/ivfscan.c

@@ -259,19 +259,27 @@ ivfflatbeginscan(Relation index, int nkeys, int norderbys)
 	/* Get lists and dimensions from metapage */
 	IvfflatGetMetaPageInfo(index, &lists, &dimensions);
 
-	if (probes > lists)
-		probes = lists;
-
 	if (ivfflat_iterative_search != IVFFLAT_ITERATIVE_SEARCH_OFF)
 	{
-		if (ivfflat_max_probes == 0)
+		maxProbes = ivfflat_max_probes;
+
+		if (maxProbes < 0)
 			maxProbes = lists;
-		else
-			maxProbes = Min(ivfflat_max_probes, lists);
+		else if (maxProbes < probes)
+		{
+			/* TODO Show notice */
+			maxProbes = probes;
+		}
 	}
 	else
 		maxProbes = probes;
 
+	if (probes > lists)
+		probes = lists;
+
+	if (maxProbes > lists)
+		maxProbes = lists;
+
 	so = (IvfflatScanOpaque) palloc(offsetof(IvfflatScanOpaqueData, lists) + maxProbes * sizeof(IvfflatScanList));
 	so->typeInfo = IvfflatGetTypeInfo(index);
 	so->first = true;