From 5befbed4bc4f074a799ec413f595eb21f6cf06c2 Mon Sep 17 00:00:00 2001
From: Simon <simon@bitcartel.com>
Date: Fri, 31 Mar 2017 10:25:39 -0400
Subject: [PATCH 1/3] Fixes #2793. Backport commit f33afd3 to increase dbcache
 default.

---
 src/txdb.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/txdb.h b/src/txdb.h
index a2764b8c2..04ac8627b 100644
--- a/src/txdb.h
+++ b/src/txdb.h
@@ -20,8 +20,8 @@ struct CDiskTxPos;
 class uint256;
 
 //! -dbcache default (MiB)
-static const int64_t nDefaultDbCache = 100;
-//! max. -dbcache in (MiB)
+static const int64_t nDefaultDbCache = 450;
+//! max. -dbcache (MiB)
 static const int64_t nMaxDbCache = sizeof(void*) > 4 ? 16384 : 1024;
 //! min. -dbcache in (MiB)
 static const int64_t nMinDbCache = 4;

From 334d591377896421e356dfbfb57c8f9022970cf3 Mon Sep 17 00:00:00 2001
From: Simon <simon@bitcartel.com>
Date: Wed, 17 Jan 2018 16:55:26 -0800
Subject: [PATCH 2/3] Add documentation about dbcache.

Adapted from documentation 'Reducing bitcoind memory usage' by @laanwj
https://gist.github.com/laanwj/efe29c7661ce9b6620a7
---
 doc/reducing-memory-usage.md | 8 ++++++++
 1 file changed, 8 insertions(+)
 create mode 100644 doc/reducing-memory-usage.md

diff --git a/doc/reducing-memory-usage.md b/doc/reducing-memory-usage.md
new file mode 100644
index 000000000..333ea0086
--- /dev/null
+++ b/doc/reducing-memory-usage.md
@@ -0,0 +1,8 @@
+In-memory caches
+----------------
+
+The size of some in-memory caches can be reduced. As caches trade off memory usage for performance, usually reducing these have a negative effect on performance.
+
+- `-dbcache=<n>` - the UTXO database cache size, this defaults to `450` (`100` before 1.0.15). The unit is MiB (where 1 GiB = 1024 MiB).
+  - The minimum value for `-dbcache` is 4.
+  - A lower dbcache make initial sync time much longer. After the initial sync, the effect is less pronounced for most use-cases, unless fast validation of blocks is important such as for mining.

From d2b77b7afa4b0015c4bffe554a76d8da5a1a93ce Mon Sep 17 00:00:00 2001
From: Simon <simon@bitcartel.com>
Date: Fri, 19 Jan 2018 16:52:25 -0800
Subject: [PATCH 3/3] Add note about dbcache to 1.0.15 release notes.

Adapted from upstream release notes here:
https://github.com/bitcoin/bitcoin/blob/master/doc/release-notes/release-notes-0.14.1.md#utxo-memory-accounting
---
 doc/release-notes.md | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/doc/release-notes.md b/doc/release-notes.md
index a29094b51..7355bcfc6 100644
--- a/doc/release-notes.md
+++ b/doc/release-notes.md
@@ -4,3 +4,9 @@ release-notes at release time)
 Notable changes
 ===============
 
+UTXO memory accounting
+----------------------
+
+The default -dbcache has been changed in this release to 450MiB. Users can set -dbcache to a higher value (e.g. to keep the UTXO set more fully cached in memory). Users on low-memory systems (such as systems with 1GB or less) should consider specifying a lower value for this parameter.
+
+Additional information relating to running on low-memory systems can be found here: [reducing-memory-usage.md](https://github.com/zcash/zcash/blob/master/doc/reducing-memory-usage.md).