From 1025b9fa76089d5d622feabbae339171f56f3702 Mon Sep 17 00:00:00 2001 From: Keith Bostic Date: Sun, 3 May 2015 11:51:21 -0400 Subject: Add LZ4 raw support based on the new LZ4_compress_destSize API, making it the default (LZ4 block mode is now lz4-noraw, to match zlib). This implementation mostly works, but... It's not backward compatible because we're storing more information in the destination buffer than before (two 4B values instead of a one 8B value). The 2.5.3 release is the only release that had LZ4 support, so I don't expect this to be a problem. We could be backward compatible, but not without a fair amount of pain. This code sizes decompression buffers incorrectly. The WiredTiger btree code sizes the decompression buffer based on the final in-memory size of the data, which isn't correct for data compressed with LZ4's raw compression function which may have compressed more data than the final in-memory size. --- src/docs/upgrading.dox | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'src/docs') diff --git a/src/docs/upgrading.dox b/src/docs/upgrading.dox index 77d290b48c0..1eaef7eea3b 100644 --- a/src/docs/upgrading.dox +++ b/src/docs/upgrading.dox @@ -2,6 +2,7 @@ @section version_254 Upgrading to Version 2.5.4
+
File handle closing
In WiredTiger, a separate thread of control periodically reviews open @@ -15,6 +16,13 @@ triggered, can be configured using the \c file_manager configuration values to the ::wiredtiger_open call.
+
LZ4 compression
+
+The LZ4 compression support has been updated in this release in non-backward +compatible ways; tables and files compressed using LZ4 compression should be +dumped and re-loaded into a new database. +
+
@section version_253 Upgrading to Version 2.5.3
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