The following list identifies
some usage notes:
-
The engine does not support views
or BY-group processing.
-
You cannot replace or overwrite
tables in memory. You must unload the table and then load the new
table.
-
You cannot use the APPEND procedure.
However, you can use an APPEND= data set option to achieve the same
result.
-
Loading tables into memory from
HDFS is performed with the LASR procedure. You cannot load tables
into memory from HDFS with the engine.
-
The engine guarantees the data
order for a particular configuration of worker nodes. If you load
a table in to a server and you retrieve the data three times, the
order of the data is the same. However, if you start another server
and load the same table into a different number of worker nodes, then
the order in which you retrieve the data is different. However, it
is reproducible within fetches from a single server.
-
Any order-dependent operation,
such as the LAG or DIF functions, cannot rely on stability of results
beyond that which can be guaranteed by the distribution model of the
data.