pgsql: Reset, not recreate, execGrouping.c style hashtables.

2019-02-09 Thread Andres Freund
Reset, not recreate, execGrouping.c style hashtables. This uses the facility added in the preceding commit to fix performance issues caused by rebuilding the hashtable (with its comparator expression being the most expensive bit), after every reset. That's especially important when the comparator

pgsql: Reset, not recreate, execGrouping.c style hashtables.

2019-02-09 Thread Andres Freund
Reset, not recreate, execGrouping.c style hashtables. This uses the facility added in the preceding commit to fix performance issues caused by rebuilding the hashtable (with its comparator expression being the most expensive bit), after every reset. That's especially important when the comparator