public inbox for [email protected]
help / color / mirror / Atom feedFrom: Schoemans Maxime <[email protected]>
To: PostgreSQL Hackers <[email protected]>
Cc: SAKR Mahmoud <[email protected]>
Cc: Diogo Repas <[email protected]>
Cc: LUO Zhicheng <[email protected]>
Cc: Tomas Vondra <[email protected]>
Cc: Andrey Lepikhov <[email protected]>
Subject: Re: Implement missing join selectivity estimation for range types
Date: Mon, 19 Jun 2023 16:26:09 +0000
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
References: <CAB4o4asMq3k6HN9WfDsssQ5DDVfAziB4TpiFJ8RBJgZTVuwC7g@mail.gmail.com>
<[email protected]>
<[email protected]>
<CAB4o4aud47V_iRyWtA8+ZAmdXDjCF165R73AeCjx2RL0nzQzHA@mail.gmail.com>
<[email protected]>
<[email protected]>
<CAB4o4asvPN=NT7KvS9zVQjZbdsiRW5t8aQctEkW7mxc4hbBxVQ@mail.gmail.com>
<[email protected]>
<[email protected]>
This is a quick correction as the last patch contained a missing semicolon.
Regards,
Maxime Schoemans
Attachments:
[text/x-patch] v2-0002-apply-division-before-adding-remainder.patch (1.5K, 2-v2-0002-apply-division-before-adding-remainder.patch)
download | inline diff:
From ebd62356210eff2f38772a9c46a0a8792c0e9ce3 Mon Sep 17 00:00:00 2001
From: Maxime Schoemans <[email protected]>
Date: Mon, 20 Mar 2023 11:48:05 -0400
Subject: [PATCH v2] Apply division before adding remainder
---
src/backend/utils/adt/multirangetypes_selfuncs.c | 5 ++++-
src/backend/utils/adt/rangetypes_selfuncs.c | 5 ++++-
2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/src/backend/utils/adt/multirangetypes_selfuncs.c b/src/backend/utils/adt/multirangetypes_selfuncs.c
index 7ba4aa8b04..ad14b789f4 100644
--- a/src/backend/utils/adt/multirangetypes_selfuncs.c
+++ b/src/backend/utils/adt/multirangetypes_selfuncs.c
@@ -1412,11 +1412,14 @@ calc_hist_join_selectivity(TypeCacheEntry *typcache,
prev_sel2 = cur_sel2;
}
+ /* P(X < Y) = 0.5 * Sum(...) */
+ selectivity /= 2;
+
/* Include remainder of hist2 if any */
if (j < nhist2)
selectivity += 1 - prev_sel2;
- return selectivity / 2;
+ return selectivity;
}
/*
diff --git a/src/backend/utils/adt/rangetypes_selfuncs.c b/src/backend/utils/adt/rangetypes_selfuncs.c
index 007e14bcf6..90970943b3 100644
--- a/src/backend/utils/adt/rangetypes_selfuncs.c
+++ b/src/backend/utils/adt/rangetypes_selfuncs.c
@@ -1342,11 +1342,14 @@ calc_hist_join_selectivity(TypeCacheEntry *typcache,
prev_sel2 = cur_sel2;
}
+ /* P(X < Y) = 0.5 * Sum(...) */
+ selectivity /= 2;
+
/* Include remainder of hist2 if any */
if (j < nhist2)
selectivity += 1 - prev_sel2;
- return selectivity / 2;
+ return selectivity;
}
/*
--
2.17.1
view thread (2+ messages)
reply
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: [email protected]
Cc: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
Subject: Re: Implement missing join selectivity estimation for range types
In-Reply-To: <[email protected]>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox