Index: src/docbkx/book.xml =================================================================== --- src/docbkx/book.xml (revision 1091086) +++ src/docbkx/book.xml (working copy) @@ -1235,6 +1235,26 @@ + + Does HBase support SQL? + + + Not really. SQL-ish support for HBase via Hive is in development, however Hive is based on MapReduce which is not generally suitable for low-latency requests. + See the Data Model section for examples on the HBase client. + + + + + How does HBase work on top of HDFS? + + + HDFS is a distributed file system that is well suited for the storage of large files. It's documentation + states that it is not, however, a general purpose file system, and does not provide fast individual record lookups in files. + HBase, on the other hand, is built on top of HDFS and provides fast record lookups (and updates) for large tables. This can sometimes be a point of conceptual confusion. + See the Data Model and Architecture sections for more information on how HBase achieves its goals. + + + Why are logs flooded with '2011-01-10 12:40:48,407 INFO org.apache.hadoop.io.compress.CodecPool: Got brand-new compressor' messages?