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authorFrank Baker <fbaker@hdfgroup.org>2001-08-02 16:10:11 (GMT)
committerFrank Baker <fbaker@hdfgroup.org>2001-08-02 16:10:11 (GMT)
commitcc9452e346694f69288ba8d152f41fa65e475ff8 (patch)
tree8a1c46244a38e4580df34a96bdf58067b5e7b98e
parent35819c2142ab789c689e3eb2afe7c06c9992ec20 (diff)
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[svn-r4303] Purpose:
Bringing 'last minute' release branch edits into development branch. Description: Chunking.html, Filters.html, and Performance.html Added links, with explanatory note, from the first 2 files above to the new freespace management section in Performance.html. Platforms tested: IE 5
-rw-r--r--doc/html/Chunking.html22
-rw-r--r--doc/html/Filters.html20
-rw-r--r--doc/html/Performance.html4
3 files changed, 40 insertions, 6 deletions
diff --git a/doc/html/Chunking.html b/doc/html/Chunking.html
index f898f58..8fd363a 100644
--- a/doc/html/Chunking.html
+++ b/doc/html/Chunking.html
@@ -58,6 +58,7 @@
<li><a href="#S3">3. Cache Efficiency</a>
<li><a href="#S4">4. Fragmentation</a>
<li><a href="#S5">5. File Storage Overhead</a>
+ <li><a href="#S6">6. Chunk Compression</a>
</ul>
<h2><a name="S1">1. Introduction</a></h2>
@@ -215,7 +216,22 @@
<code>H5Pset_istore_k()</code> (increasing the out degree actually
increases file overhead while decreasing the number of nodes).
- <hr>
+
+ <h2><a name="S6">6. Chunk Compression</a></h2>
+
+ <p>Dataset chunks can be compressed through the use of filters.
+ See the chapter &ldquo;<a href="Filters.html">Filters in HDF5</a>.&rdquo;
+
+ <p>Reading and rewriting compressed chunked data can result in holes
+ in an HDF5 file. In time, enough such holes can increase the
+ file size enough to impair application or library performance
+ when working with that file. See
+ &ldquo;<a href="Performance.html#Freespace">Freespace Management</a>&rdquo;
+ in the chapter
+ &ldquo;<a href="Performance.html">Performance Analysis and Issues</a>.&rdquo;
+
+
+<hr>
<p><a name="fn1">Footnote 1:</a> Parallel versions of the library
can access individual bytes of a chunk when the underlying file
@@ -224,7 +240,6 @@
<p><a name="fn2">Footnote 2:</a> The raw data chunk cache was
added before the second alpha release.
-
<hr>
<center>
<table border=0 width=98%>
@@ -273,12 +288,13 @@
<!-- Created: Tue Oct 20 12:38:40 EDT 1998 -->
<!-- hhmts start -->
-Last modified: 16 February 2001
+Last modified: 2 August 2001
<!-- hhmts end -->
<br>
Describes HDF5 Release 1.5, Unreleased Development Branch
+
</body>
</html>
diff --git a/doc/html/Filters.html b/doc/html/Filters.html
index e4efc5f..f292bfd 100644
--- a/doc/html/Filters.html
+++ b/doc/html/Filters.html
@@ -55,7 +55,8 @@
<h2>1. Introduction</h2>
- <p>HDF5 allows chunked data to pass through user-defined filters
+ <p>HDF5 allows chunked data<sup><a href="#fn1">1</a></sup>
+ to pass through user-defined filters
on the way to or from disk. The filters operate on chunks of an
<code>H5D_CHUNKED</code> dataset can be arranged in a pipeline
so output of one filter becomes the input of the next filter.
@@ -507,6 +508,21 @@ H5Z: filter statistics accumulated over life of library:
<hr>
+
+
+ <p><a name="fn1">Footnote 1:</a> Dataset chunks can be compressed
+ through the use of filters. Developers should be aware that
+ reading and rewriting compressed chunked data can result in holes
+ in an HDF5 file. In time, enough such holes can increase the
+ file size enough to impair application or library performance
+ when working with that file. See
+ &ldquo;<a href="Performance.html#Freespace">Freespace Management</a>&rdquo;
+ in the chapter
+ &ldquo;<a href="Performance.html">Performance Analysis and Issues</a>.&rdquo;
+
+
+
+<hr>
<center>
<table border=0 width=98%>
<tr><td valign=top align=left>
@@ -554,7 +570,7 @@ H5Z: filter statistics accumulated over life of library:
<!-- Created: Fri Apr 17 13:39:35 EDT 1998 -->
<!-- hhmts start -->
-Last modified: 17 December 1999
+Last modified: 2 August 2001
<!-- hhmts end -->
<br>
diff --git a/doc/html/Performance.html b/doc/html/Performance.html
index 36accbf..5486e57 100644
--- a/doc/html/Performance.html
+++ b/doc/html/Performance.html
@@ -63,7 +63,9 @@
<a href="Chunking.html">Dataset Chunking Issues</a> elsewhere
in this <cite>User's Guide</cite>.
+ <a name="Freespace">
<h2>3. Freespace Management</h2>
+ </a>
<p>HDF5 does not yet manage freespace as effectively as it might.
While a file is opened, the library actively tracks and re-uses
@@ -235,7 +237,7 @@
<!-- Created: Thu Oct 14 16:46:00 CDT 1999 -->
<!-- hhmts start -->
-Last modified: 11 July 2001
+Last modified: 2 August 2001
<!-- hhmts end -->
<br>