diff --git a/doc/src/sgml/indexam.sgml b/doc/src/sgml/indexam.sgml
index c72c522175..beb99d1831 100644
--- a/doc/src/sgml/indexam.sgml
+++ b/doc/src/sgml/indexam.sgml
@@ -385,7 +385,8 @@ amcostestimate (PlannerInfo *root,
Cost *indexStartupCost,
Cost *indexTotalCost,
Selectivity *indexSelectivity,
- double *indexCorrelation);
+ double *indexCorrelation,
+ double *indexPages);
Estimate the costs of an index scan. This function is described fully
in , below.
@@ -1155,7 +1156,8 @@ amcostestimate (PlannerInfo *root,
Cost *indexStartupCost,
Cost *indexTotalCost,
Selectivity *indexSelectivity,
- double *indexCorrelation);
+ double *indexCorrelation,
+ double *indexPages);
The first three parameters are inputs:
@@ -1197,7 +1199,7 @@ amcostestimate (PlannerInfo *root,
- The last four parameters are pass-by-reference outputs:
+ The last five parameters are pass-by-reference outputs:
@@ -1236,6 +1238,15 @@ amcostestimate (PlannerInfo *root,
+
+
+ *indexPages
+
+
+ Set to number of index leaf pages
+
+
+
@@ -1283,6 +1294,11 @@ amcostestimate (PlannerInfo *root,
table.
+
+ The indexPages should be set to the number of leaf pages.
+ This is used to estimate the number of workers for parallel index scan.
+
+
When loop_count is greater than one, the returned numbers
should be averages expected for any one scan of the index.