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The "Avro/Glossary" page has been changed by JeffHammerbacher.
http://wiki.apache.org/hadoop/Avro/Glossary?action=diff&rev1=6&rev2=7

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   * '''block''': Array and Maps are encoded as a series of blocks, with a 
"count" long at the beginning of each block (and optionally "size"). Used for 
reading and writing data structures that don't fit into memory (maybe; not 
implemented yet). May also refer to the "blocks" in a file object container.
   * '''!DatumReader'''/'''!DatumWriter'''
   * '''!DataFileReader'''/'''!DataFileWriter'''
+  * '''Projection''': The ability to select a subset of data from an Avro 
schema by specifying an "expected" schema with the objects you'd like to read. 
Can possibly avoid the overhead of deserialization of all columns when you only 
want a few.
  
  === IPC ===
   * '''requestor'''
@@ -13, +14 @@

   * '''transceiver'''
  
  === Other ===
-  * '''specific'''
+  * '''specific''': take advantage of language-specific features when 
implementing a schema (e.g. code generation of Java classes in the Java 
implementation).
   * '''generic'''
-  * '''reflect'''
+  * '''reflect''': generate an Avro schema by looking
  
  Most Avro terms of art are defined in the 
[[http://hadoop.apache.org/avro/docs/current/spec.html|specification]].
  

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