Index: src/docbkx/performance.xml
===================================================================
--- src/docbkx/performance.xml (revision 1459918)
+++ src/docbkx/performance.xml (working copy)
@@ -287,6 +287,31 @@
+
+ HBase General Patterns
+
+ Constants
+ When people get started with HBase they have a tendency to write code that looks like this:
+
+Get get = new Get(rowkey);
+Result r = htable.get(get);
+byte[] b = r.getValue(Bytes.toBytes("cf"), Bytes.toBytes("attr")); // returns current version of value
+
+ But especially when inside loops (and MapReduce jobs), converting the columnFamily and column-names
+ to byte-arrays repeatedly is surprsingly expensive.
+ It's better to use constants for the byte-arrays, like this:
+
+public static final byte[] CF = "cf".getBytes();
+public static final byte[] ATTR = "attr".getBytes();
+...
+Get get = new Get(rowkey);
+Result r = htable.get(get);
+byte[] b = r.getValue(CF, ATTR); // returns current version of value
+
+
+
+
+