From ba391ca500a514652fd24cc009eb92583e8263ea Mon Sep 17 00:00:00 2001
From: Julien Rouhaud <julien.rouhaud@free.fr>
Date: Tue, 17 Mar 2015 00:31:44 +0100
Subject: [PATCH] Fix index pages estimation

---
 pg_hypo.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/pg_hypo.c b/pg_hypo.c
index 1a86d94..a6d7310 100644
--- a/pg_hypo.c
+++ b/pg_hypo.c
@@ -332,9 +332,10 @@ addHypotheticalIndex(PlannerInfo *root,
 	if (index->indpred == NIL)
 	{
 		/* very quick and pessimistic estimation :
-		 * number of tuples * avg width, with ~ 50% bloat, plus 1 block
+		 * number of tuples * avg width,
+		 * with ~ 50% bloat (including 10% fillfactor), plus 1 block
 		 */
-		index->pages = (rel->tuples * ind_avg_width * .5 / BLCKSZ) + 1;
+		index->pages = (rel->tuples * ind_avg_width * 2 / BLCKSZ) + 1;
 		/* partial index not supported yet, so assume all tuples are in the index */
 		index->tuples = rel->tuples;
 	}