Experimental optimization for distinct aggregates (e.g. "SELECT count(DISTINCT <expr) FROM ...").

FossilOrigin-Name: eb919611fd2f255e4ad1fe7db633363793169f6cf99c650eaefa48c022eb5d22

src/sqliteInt.h

@@ -2598,6 +2598,7 @@ struct AggInfo {
     FuncDef *pFunc;          /* The aggregate function implementation */
     int iMem;                /* Memory location that acts as accumulator */
     int iDistinct;           /* Ephemeral table used to enforce DISTINCT */
+    int iDistAddr;           /* Addres of OP_OpenEphemeral */
   } *aFunc;
   int nFunc;              /* Number of entries in aFunc[] */
   u32 selId;              /* Select to which this AggInfo belongs */