Enable backward sequential scan even after reaching EOF.

Hiroshi Inoue · Hiroshi Inoue · commit 3dec14197bba · 2000-02-09T03:49:47.000Z
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/heap/heapam.c,v 1.65 2000/01/26 05:55:56 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/heap/heapam.c,v 1.66 2000/02/09 03:49:47 inoue Exp $
  *
  *
  * INTERFACE ROUTINES
@@ -848,11 +848,6 @@ heap_getnext(HeapScanDesc scandesc, int backw)
 		if (scan->rs_ptup.t_data == scan->rs_ctup.t_data &&
 			BufferIsInvalid(scan->rs_pbuf))
 		{
-			if (BufferIsValid(scan->rs_nbuf))
-				ReleaseBuffer(scan->rs_nbuf);
-			scan->rs_ntup.t_datamcxt = NULL;
-			scan->rs_ntup.t_data = NULL;
-			scan->rs_nbuf = UnknownBuffer;
 			return NULL;
 		}
 
@@ -910,11 +905,6 @@ heap_getnext(HeapScanDesc scandesc, int backw)
 			scan->rs_ptup.t_datamcxt = NULL;
 			scan->rs_ptup.t_data = NULL;
 			scan->rs_pbuf = InvalidBuffer;
-			if (BufferIsValid(scan->rs_nbuf))
-				ReleaseBuffer(scan->rs_nbuf);
-			scan->rs_ntup.t_datamcxt = NULL;
-			scan->rs_ntup.t_data = NULL;
-			scan->rs_nbuf = InvalidBuffer;
 			return NULL;
 		}
 
@@ -934,11 +924,6 @@ heap_getnext(HeapScanDesc scandesc, int backw)
 		if (scan->rs_ctup.t_data == scan->rs_ntup.t_data &&
 			BufferIsInvalid(scan->rs_nbuf))
 		{
-			if (BufferIsValid(scan->rs_pbuf))
-				ReleaseBuffer(scan->rs_pbuf);
-			scan->rs_ptup.t_datamcxt = NULL;
-			scan->rs_ptup.t_data = NULL;
-			scan->rs_pbuf = UnknownBuffer;
 			HEAPDEBUG_3;		/* heap_getnext returns NULL at end */
 			return NULL;
 		}
@@ -998,11 +983,6 @@ heap_getnext(HeapScanDesc scandesc, int backw)
 			scan->rs_ntup.t_datamcxt = NULL;
 			scan->rs_ntup.t_data = NULL;
 			scan->rs_nbuf = InvalidBuffer;
-			if (BufferIsValid(scan->rs_pbuf))
-				ReleaseBuffer(scan->rs_pbuf);
-			scan->rs_ptup.t_datamcxt = NULL;
-			scan->rs_ptup.t_data = NULL;
-			scan->rs_pbuf = InvalidBuffer;
 			HEAPDEBUG_6;		/* heap_getnext returning EOS */
 			return NULL;
 		}

Original file line number	Diff line number	Diff line change
`@@ -8,7 +8,7 @@`
`8`	`8`	`*`
`9`	`9`	`*`
`10`	`10`	`* IDENTIFICATION`
`11`		`- * $Header: /cvsroot/pgsql/src/backend/access/heap/heapam.c,v 1.65 2000/01/26 05:55:56 momjian Exp $`
	`11`	`+ * $Header: /cvsroot/pgsql/src/backend/access/heap/heapam.c,v 1.66 2000/02/09 03:49:47 inoue Exp $`
`12`	`12`	`*`
`13`	`13`	`*`
`14`	`14`	`* INTERFACE ROUTINES`
`@@ -848,11 +848,6 @@ heap_getnext(HeapScanDesc scandesc, int backw)`
`848`	`848`	`if (scan->rs_ptup.t_data == scan->rs_ctup.t_data &&`
`849`	`849`	`BufferIsInvalid(scan->rs_pbuf))`
`850`	`850`	`{`
`851`		`- if (BufferIsValid(scan->rs_nbuf))`
`852`		`- ReleaseBuffer(scan->rs_nbuf);`
`853`		`- scan->rs_ntup.t_datamcxt = NULL;`
`854`		`- scan->rs_ntup.t_data = NULL;`
`855`		`- scan->rs_nbuf = UnknownBuffer;`
`856`	`851`	`return NULL;`
`857`	`852`	`}`
`858`	`853`
`@@ -910,11 +905,6 @@ heap_getnext(HeapScanDesc scandesc, int backw)`
`910`	`905`	`scan->rs_ptup.t_datamcxt = NULL;`
`911`	`906`	`scan->rs_ptup.t_data = NULL;`
`912`	`907`	`scan->rs_pbuf = InvalidBuffer;`
`913`		`- if (BufferIsValid(scan->rs_nbuf))`
`914`		`- ReleaseBuffer(scan->rs_nbuf);`
`915`		`- scan->rs_ntup.t_datamcxt = NULL;`
`916`		`- scan->rs_ntup.t_data = NULL;`
`917`		`- scan->rs_nbuf = InvalidBuffer;`
`918`	`908`	`return NULL;`
`919`	`909`	`}`
`920`	`910`
`@@ -934,11 +924,6 @@ heap_getnext(HeapScanDesc scandesc, int backw)`
`934`	`924`	`if (scan->rs_ctup.t_data == scan->rs_ntup.t_data &&`
`935`	`925`	`BufferIsInvalid(scan->rs_nbuf))`
`936`	`926`	`{`
`937`		`- if (BufferIsValid(scan->rs_pbuf))`
`938`		`- ReleaseBuffer(scan->rs_pbuf);`
`939`		`- scan->rs_ptup.t_datamcxt = NULL;`
`940`		`- scan->rs_ptup.t_data = NULL;`
`941`		`- scan->rs_pbuf = UnknownBuffer;`
`942`	`927`	`HEAPDEBUG_3; /* heap_getnext returns NULL at end */`
`943`	`928`	`return NULL;`
`944`	`929`	`}`
`@@ -998,11 +983,6 @@ heap_getnext(HeapScanDesc scandesc, int backw)`
`998`	`983`	`scan->rs_ntup.t_datamcxt = NULL;`
`999`	`984`	`scan->rs_ntup.t_data = NULL;`
`1000`	`985`	`scan->rs_nbuf = InvalidBuffer;`
`1001`		`- if (BufferIsValid(scan->rs_pbuf))`
`1002`		`- ReleaseBuffer(scan->rs_pbuf);`
`1003`		`- scan->rs_ptup.t_datamcxt = NULL;`
`1004`		`- scan->rs_ptup.t_data = NULL;`
`1005`		`- scan->rs_pbuf = InvalidBuffer;`
`1006`	`986`	`HEAPDEBUG_6; /* heap_getnext returning EOS */`
`1007`	`987`	`return NULL;`
`1008`	`988`	`}`