size to 1GB. We did not compress data in PostgreSQL.
Analogous to what we did for Hadoop, we present results of
both hand-coded HadoopDB and SMS-coded HadoopDB (i.e. entire
query plans created by HadoopDB’s SMS planner). These separate
results for HadoopDB are displayed as split bars in the graphs.
The bottom, colored segment of the bars represents the time taken
by HadoopDB when hand-coded and the rest of the bar indicates
the additional overhead as a result of the SMS planner (e.g., SMS
jobs need to serialize tuples retrieved from the underlying database
and deserialize them before further processing in Hadoop).