Commits on Aug 7, 2017

1. Specialize row_group_slots() and findrow() on column types to improve… …

   … performance
   
   Looping over columns is very slow when their type is unknown at compile time.
   Specialize the method on the types of the key (grouping) columns by passing
   a tuple of columns rather than a DataTable. This will force compiling a specific
   method for each combination of key types, but their number should remain relatively low
   and the one-time cost is worth it.
   
   This dramatically improves performance of groupby(), but does not have a large
   effect on join() since it is very inefficient in other areas.
   
   Also add return type assertion for rowhash(). The fact that the type of
   the columns isn't known at compile time appears to confuse inference,
   which isn't able to detect that this function always returns UInt.
   This reduces a lot the number of allocations when calling join(),
   but doesn't really change performance.

   

   nalimilan committed Aug 7, 2017
   Configuration menu

   • View commit details
   • Copy full SHA for 9e327e1
   • Browse repository at this point

   Copy the full SHA

   9e327e1 View commit details

   Browse the repository at this point in the history