Index: src/docbkx/book.xml
===================================================================
--- src/docbkx/book.xml (revision 1414702)
+++ src/docbkx/book.xml (working copy)
@@ -942,9 +942,20 @@
tables, such as having 1 row with 1 million attributes, or 1 million rows with 1 columns apiece.
Preference: Rows (generally speaking). To be clear, this guideline is in the context is in extremely wide cases, not in the
- standard use-case where one needs to store a few dozen or hundred columns.
+ standard use-case where one needs to store a few dozen or hundred columns. But there is also a middle path between these two
+ options, and that is "Rows as Columns."
+
+
+ Rows as Columns
+ The middle path between Rows vs. Columns is packing data that would be a separate row into columns, for certain rows.
+ OpenTSDB is the best example of this case where a single row represents a defined time-range, and then discrete events are treated as
+ columns. This approach is often more complex, and may require the additional complexity of re-writing your data, but has the
+ advantage of being I/O efficient. For an overview of this approach, see
+ Lessons Learned from OpenTSDB
+ from HBaseCon2012.
+
Operational and Performance Configuration OptionsSee the Performance section for more information operational and performance