Some comments

Author: Arthur Zakirov

src/rum.h

@@ -682,21 +682,25 @@ typedef enum
 
 typedef struct RumScanOpaqueData
 {
+	/* tempCtx is used to hold consistent and ordering functions data */
 	MemoryContext tempCtx;
-	MemoryContext keyCtx;		/* used to hold key and entry data */
+	/* keyCtx is used to hold key and entry data */
+	MemoryContext keyCtx;
 	RumState	rumstate;
 
-	RumScanKey	*keys;			/* one per scan qualifier expr */
+	RumScanKey *keys;				/* one per scan qualifier expr */
 	uint32		nkeys;
-	int			norderbys;
 
-	RumScanEntry *entries;		/* one per index search condition */
-	RumScanEntry *sortedEntries;	/* one per index search condition */
-	int			entriesIncrIndex;
+	RumScanEntry *entries;			/* one per index search condition */
+	RumScanEntry *sortedEntries;	/* Sorted entries. Used in fast scan */
+	int			entriesIncrIndex;	/* used in fast scan */
 	uint32		totalentries;
-	uint32		allocentries;	/* allocated length of entries[] */
+	uint32		allocentries;		/* allocated length of entries[] and
+									   sortedEntries[] */
 
 	Tuplesortstate *sortstate;
+	int			norderbys;		/* Number of columns in ordering.
+								   Will be assigned to sortstate->nKeys */
 
 	RumKey		key;
 	bool		firstCall;

src/rumget.c

@@ -2033,6 +2033,7 @@ rumgetbitmap(IndexScanDesc scan, TIDBitmap *tbm)
 	RumScanOpaque so = (RumScanOpaque) scan->opaque;
 	int64		ntids = 0;
 	bool		recheck;
+	RumKey		key;
 
 	/*
 	 * Set up the scan keys, and check for unsatisfiable query.
@@ -2063,14 +2064,16 @@ rumgetbitmap(IndexScanDesc scan, TIDBitmap *tbm)
 	 */
 	startScan(scan);
 
+	ItemPointerSetInvalid(&key.iptr);
+
 	for (;;)
 	{
 		CHECK_FOR_INTERRUPTS();
 
-		if (!scanGetItem(scan, &so->key, &so->key, &recheck))
+		if (!scanGetItem(scan, &key, &key, &recheck))
 			break;
 
-		tbm_add_tuples(tbm, &so->key.iptr, 1, recheck);
+		tbm_add_tuples(tbm, &key.iptr, 1, recheck);
 		ntids++;
 	}
 

src/rumscan.c

@@ -547,7 +547,7 @@ rumNewScanKey(IndexScanDesc scan)
 	oldCtx = MemoryContextSwitchTo(so->keyCtx);
 
 	/* if no scan keys provided, allocate extra EVERYTHING RumScanKey */
-	so->keys = (RumScanKey*)
+	so->keys = (RumScanKey *)
 		palloc((Max(scan->numberOfKeys, 1) + scan->numberOfOrderBys) *
 			   sizeof(*so->keys));
 	so->nkeys = 0;