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[PATCH v3 3/3] Fix sizing of tape read buffers.
21+ messages / 1 participants
[nested] [flat]

* [PATCH v3 3/3] Fix sizing of tape read buffers.
@ 2021-01-22 20:59  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 21+ messages in thread

From: Heikki Linnakangas @ 2021-01-22 20:59 UTC (permalink / raw)

---
 src/backend/utils/sort/tuplesort.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c
index 14104643e78..aff2f201f52 100644
--- a/src/backend/utils/sort/tuplesort.c
+++ b/src/backend/utils/sort/tuplesort.c
@@ -2658,7 +2658,7 @@ merge_read_buffer_size(int64 avail_mem, int nInputTapes, int nInputRuns,
 	 * we derive the input buffer size from the amount of memory available,
 	 * and M and N.
 	 */
-	return (avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes;
+	return Max((avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes, 0);
 }
 
 /*
-- 
2.29.2


--------------631E0A48DCAEA386819DFCEC--





^ permalink  raw  reply  [nested|flat] 21+ messages in thread

* [PATCH v3 3/3] Fix sizing of tape read buffers.
@ 2021-01-22 20:59  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 21+ messages in thread

From: Heikki Linnakangas @ 2021-01-22 20:59 UTC (permalink / raw)

---
 src/backend/utils/sort/tuplesort.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c
index 14104643e78..aff2f201f52 100644
--- a/src/backend/utils/sort/tuplesort.c
+++ b/src/backend/utils/sort/tuplesort.c
@@ -2658,7 +2658,7 @@ merge_read_buffer_size(int64 avail_mem, int nInputTapes, int nInputRuns,
 	 * we derive the input buffer size from the amount of memory available,
 	 * and M and N.
 	 */
-	return (avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes;
+	return Max((avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes, 0);
 }
 
 /*
-- 
2.29.2


--------------631E0A48DCAEA386819DFCEC--





^ permalink  raw  reply  [nested|flat] 21+ messages in thread

* [PATCH v3 3/3] Fix sizing of tape read buffers.
@ 2021-01-22 20:59  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 21+ messages in thread

From: Heikki Linnakangas @ 2021-01-22 20:59 UTC (permalink / raw)

---
 src/backend/utils/sort/tuplesort.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c
index 14104643e78..aff2f201f52 100644
--- a/src/backend/utils/sort/tuplesort.c
+++ b/src/backend/utils/sort/tuplesort.c
@@ -2658,7 +2658,7 @@ merge_read_buffer_size(int64 avail_mem, int nInputTapes, int nInputRuns,
 	 * we derive the input buffer size from the amount of memory available,
 	 * and M and N.
 	 */
-	return (avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes;
+	return Max((avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes, 0);
 }
 
 /*
-- 
2.29.2


--------------631E0A48DCAEA386819DFCEC--





^ permalink  raw  reply  [nested|flat] 21+ messages in thread

* [PATCH v3 3/3] Fix sizing of tape read buffers.
@ 2021-01-22 20:59  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 21+ messages in thread

From: Heikki Linnakangas @ 2021-01-22 20:59 UTC (permalink / raw)

---
 src/backend/utils/sort/tuplesort.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c
index 14104643e78..aff2f201f52 100644
--- a/src/backend/utils/sort/tuplesort.c
+++ b/src/backend/utils/sort/tuplesort.c
@@ -2658,7 +2658,7 @@ merge_read_buffer_size(int64 avail_mem, int nInputTapes, int nInputRuns,
 	 * we derive the input buffer size from the amount of memory available,
 	 * and M and N.
 	 */
-	return (avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes;
+	return Max((avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes, 0);
 }
 
 /*
-- 
2.29.2


--------------631E0A48DCAEA386819DFCEC--





^ permalink  raw  reply  [nested|flat] 21+ messages in thread

* [PATCH v3 3/3] Fix sizing of tape read buffers.
@ 2021-01-22 20:59  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 21+ messages in thread

From: Heikki Linnakangas @ 2021-01-22 20:59 UTC (permalink / raw)

---
 src/backend/utils/sort/tuplesort.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c
index 14104643e78..aff2f201f52 100644
--- a/src/backend/utils/sort/tuplesort.c
+++ b/src/backend/utils/sort/tuplesort.c
@@ -2658,7 +2658,7 @@ merge_read_buffer_size(int64 avail_mem, int nInputTapes, int nInputRuns,
 	 * we derive the input buffer size from the amount of memory available,
 	 * and M and N.
 	 */
-	return (avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes;
+	return Max((avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes, 0);
 }
 
 /*
-- 
2.29.2


--------------631E0A48DCAEA386819DFCEC--





^ permalink  raw  reply  [nested|flat] 21+ messages in thread

* [PATCH v3 3/3] Fix sizing of tape read buffers.
@ 2021-01-22 20:59  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 21+ messages in thread

From: Heikki Linnakangas @ 2021-01-22 20:59 UTC (permalink / raw)

---
 src/backend/utils/sort/tuplesort.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c
index 14104643e78..aff2f201f52 100644
--- a/src/backend/utils/sort/tuplesort.c
+++ b/src/backend/utils/sort/tuplesort.c
@@ -2658,7 +2658,7 @@ merge_read_buffer_size(int64 avail_mem, int nInputTapes, int nInputRuns,
 	 * we derive the input buffer size from the amount of memory available,
 	 * and M and N.
 	 */
-	return (avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes;
+	return Max((avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes, 0);
 }
 
 /*
-- 
2.29.2


--------------631E0A48DCAEA386819DFCEC--





^ permalink  raw  reply  [nested|flat] 21+ messages in thread

* [PATCH v3 3/3] Fix sizing of tape read buffers.
@ 2021-01-22 20:59  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 21+ messages in thread

From: Heikki Linnakangas @ 2021-01-22 20:59 UTC (permalink / raw)

---
 src/backend/utils/sort/tuplesort.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c
index 14104643e78..aff2f201f52 100644
--- a/src/backend/utils/sort/tuplesort.c
+++ b/src/backend/utils/sort/tuplesort.c
@@ -2658,7 +2658,7 @@ merge_read_buffer_size(int64 avail_mem, int nInputTapes, int nInputRuns,
 	 * we derive the input buffer size from the amount of memory available,
 	 * and M and N.
 	 */
-	return (avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes;
+	return Max((avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes, 0);
 }
 
 /*
-- 
2.29.2


--------------631E0A48DCAEA386819DFCEC--





^ permalink  raw  reply  [nested|flat] 21+ messages in thread

* [PATCH v3 3/3] Fix sizing of tape read buffers.
@ 2021-01-22 20:59  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 21+ messages in thread

From: Heikki Linnakangas @ 2021-01-22 20:59 UTC (permalink / raw)

---
 src/backend/utils/sort/tuplesort.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c
index 14104643e78..aff2f201f52 100644
--- a/src/backend/utils/sort/tuplesort.c
+++ b/src/backend/utils/sort/tuplesort.c
@@ -2658,7 +2658,7 @@ merge_read_buffer_size(int64 avail_mem, int nInputTapes, int nInputRuns,
 	 * we derive the input buffer size from the amount of memory available,
 	 * and M and N.
 	 */
-	return (avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes;
+	return Max((avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes, 0);
 }
 
 /*
-- 
2.29.2


--------------631E0A48DCAEA386819DFCEC--





^ permalink  raw  reply  [nested|flat] 21+ messages in thread

* [PATCH v3 3/3] Fix sizing of tape read buffers.
@ 2021-01-22 20:59  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 21+ messages in thread

From: Heikki Linnakangas @ 2021-01-22 20:59 UTC (permalink / raw)

---
 src/backend/utils/sort/tuplesort.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c
index 14104643e78..aff2f201f52 100644
--- a/src/backend/utils/sort/tuplesort.c
+++ b/src/backend/utils/sort/tuplesort.c
@@ -2658,7 +2658,7 @@ merge_read_buffer_size(int64 avail_mem, int nInputTapes, int nInputRuns,
 	 * we derive the input buffer size from the amount of memory available,
 	 * and M and N.
 	 */
-	return (avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes;
+	return Max((avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes, 0);
 }
 
 /*
-- 
2.29.2


--------------631E0A48DCAEA386819DFCEC--





^ permalink  raw  reply  [nested|flat] 21+ messages in thread

* [PATCH v3 3/3] Fix sizing of tape read buffers.
@ 2021-01-22 20:59  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 21+ messages in thread

From: Heikki Linnakangas @ 2021-01-22 20:59 UTC (permalink / raw)

---
 src/backend/utils/sort/tuplesort.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c
index 14104643e78..aff2f201f52 100644
--- a/src/backend/utils/sort/tuplesort.c
+++ b/src/backend/utils/sort/tuplesort.c
@@ -2658,7 +2658,7 @@ merge_read_buffer_size(int64 avail_mem, int nInputTapes, int nInputRuns,
 	 * we derive the input buffer size from the amount of memory available,
 	 * and M and N.
 	 */
-	return (avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes;
+	return Max((avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes, 0);
 }
 
 /*
-- 
2.29.2


--------------631E0A48DCAEA386819DFCEC--





^ permalink  raw  reply  [nested|flat] 21+ messages in thread

* [PATCH v3 3/3] Fix sizing of tape read buffers.
@ 2021-01-22 20:59  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 21+ messages in thread

From: Heikki Linnakangas @ 2021-01-22 20:59 UTC (permalink / raw)

---
 src/backend/utils/sort/tuplesort.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c
index 14104643e78..aff2f201f52 100644
--- a/src/backend/utils/sort/tuplesort.c
+++ b/src/backend/utils/sort/tuplesort.c
@@ -2658,7 +2658,7 @@ merge_read_buffer_size(int64 avail_mem, int nInputTapes, int nInputRuns,
 	 * we derive the input buffer size from the amount of memory available,
 	 * and M and N.
 	 */
-	return (avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes;
+	return Max((avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes, 0);
 }
 
 /*
-- 
2.29.2


--------------631E0A48DCAEA386819DFCEC--





^ permalink  raw  reply  [nested|flat] 21+ messages in thread

* [PATCH v3 3/3] Fix sizing of tape read buffers.
@ 2021-01-22 20:59  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 21+ messages in thread

From: Heikki Linnakangas @ 2021-01-22 20:59 UTC (permalink / raw)

---
 src/backend/utils/sort/tuplesort.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c
index 14104643e78..aff2f201f52 100644
--- a/src/backend/utils/sort/tuplesort.c
+++ b/src/backend/utils/sort/tuplesort.c
@@ -2658,7 +2658,7 @@ merge_read_buffer_size(int64 avail_mem, int nInputTapes, int nInputRuns,
 	 * we derive the input buffer size from the amount of memory available,
 	 * and M and N.
 	 */
-	return (avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes;
+	return Max((avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes, 0);
 }
 
 /*
-- 
2.29.2


--------------631E0A48DCAEA386819DFCEC--





^ permalink  raw  reply  [nested|flat] 21+ messages in thread

* [PATCH v3 3/3] Fix sizing of tape read buffers.
@ 2021-01-22 20:59  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 21+ messages in thread

From: Heikki Linnakangas @ 2021-01-22 20:59 UTC (permalink / raw)

---
 src/backend/utils/sort/tuplesort.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c
index 14104643e78..aff2f201f52 100644
--- a/src/backend/utils/sort/tuplesort.c
+++ b/src/backend/utils/sort/tuplesort.c
@@ -2658,7 +2658,7 @@ merge_read_buffer_size(int64 avail_mem, int nInputTapes, int nInputRuns,
 	 * we derive the input buffer size from the amount of memory available,
 	 * and M and N.
 	 */
-	return (avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes;
+	return Max((avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes, 0);
 }
 
 /*
-- 
2.29.2


--------------631E0A48DCAEA386819DFCEC--





^ permalink  raw  reply  [nested|flat] 21+ messages in thread

* [PATCH v3 3/3] Fix sizing of tape read buffers.
@ 2021-01-22 20:59  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 21+ messages in thread

From: Heikki Linnakangas @ 2021-01-22 20:59 UTC (permalink / raw)

---
 src/backend/utils/sort/tuplesort.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c
index 14104643e78..aff2f201f52 100644
--- a/src/backend/utils/sort/tuplesort.c
+++ b/src/backend/utils/sort/tuplesort.c
@@ -2658,7 +2658,7 @@ merge_read_buffer_size(int64 avail_mem, int nInputTapes, int nInputRuns,
 	 * we derive the input buffer size from the amount of memory available,
 	 * and M and N.
 	 */
-	return (avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes;
+	return Max((avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes, 0);
 }
 
 /*
-- 
2.29.2


--------------631E0A48DCAEA386819DFCEC--





^ permalink  raw  reply  [nested|flat] 21+ messages in thread

* [PATCH v3 3/3] Fix sizing of tape read buffers.
@ 2021-01-22 20:59  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 21+ messages in thread

From: Heikki Linnakangas @ 2021-01-22 20:59 UTC (permalink / raw)

---
 src/backend/utils/sort/tuplesort.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c
index 14104643e78..aff2f201f52 100644
--- a/src/backend/utils/sort/tuplesort.c
+++ b/src/backend/utils/sort/tuplesort.c
@@ -2658,7 +2658,7 @@ merge_read_buffer_size(int64 avail_mem, int nInputTapes, int nInputRuns,
 	 * we derive the input buffer size from the amount of memory available,
 	 * and M and N.
 	 */
-	return (avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes;
+	return Max((avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes, 0);
 }
 
 /*
-- 
2.29.2


--------------631E0A48DCAEA386819DFCEC--





^ permalink  raw  reply  [nested|flat] 21+ messages in thread

* [PATCH v3 3/3] Fix sizing of tape read buffers.
@ 2021-01-22 20:59  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 21+ messages in thread

From: Heikki Linnakangas @ 2021-01-22 20:59 UTC (permalink / raw)

---
 src/backend/utils/sort/tuplesort.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c
index 14104643e78..aff2f201f52 100644
--- a/src/backend/utils/sort/tuplesort.c
+++ b/src/backend/utils/sort/tuplesort.c
@@ -2658,7 +2658,7 @@ merge_read_buffer_size(int64 avail_mem, int nInputTapes, int nInputRuns,
 	 * we derive the input buffer size from the amount of memory available,
 	 * and M and N.
 	 */
-	return (avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes;
+	return Max((avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes, 0);
 }
 
 /*
-- 
2.29.2


--------------631E0A48DCAEA386819DFCEC--





^ permalink  raw  reply  [nested|flat] 21+ messages in thread

* [PATCH v3 3/3] Fix sizing of tape read buffers.
@ 2021-01-22 20:59  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 21+ messages in thread

From: Heikki Linnakangas @ 2021-01-22 20:59 UTC (permalink / raw)

---
 src/backend/utils/sort/tuplesort.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c
index 14104643e78..aff2f201f52 100644
--- a/src/backend/utils/sort/tuplesort.c
+++ b/src/backend/utils/sort/tuplesort.c
@@ -2658,7 +2658,7 @@ merge_read_buffer_size(int64 avail_mem, int nInputTapes, int nInputRuns,
 	 * we derive the input buffer size from the amount of memory available,
 	 * and M and N.
 	 */
-	return (avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes;
+	return Max((avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes, 0);
 }
 
 /*
-- 
2.29.2


--------------631E0A48DCAEA386819DFCEC--





^ permalink  raw  reply  [nested|flat] 21+ messages in thread

* [PATCH v3 3/3] Fix sizing of tape read buffers.
@ 2021-01-22 20:59  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 21+ messages in thread

From: Heikki Linnakangas @ 2021-01-22 20:59 UTC (permalink / raw)

---
 src/backend/utils/sort/tuplesort.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c
index 14104643e78..aff2f201f52 100644
--- a/src/backend/utils/sort/tuplesort.c
+++ b/src/backend/utils/sort/tuplesort.c
@@ -2658,7 +2658,7 @@ merge_read_buffer_size(int64 avail_mem, int nInputTapes, int nInputRuns,
 	 * we derive the input buffer size from the amount of memory available,
 	 * and M and N.
 	 */
-	return (avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes;
+	return Max((avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes, 0);
 }
 
 /*
-- 
2.29.2


--------------631E0A48DCAEA386819DFCEC--





^ permalink  raw  reply  [nested|flat] 21+ messages in thread

* [PATCH v3 3/3] Fix sizing of tape read buffers.
@ 2021-01-22 20:59  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 21+ messages in thread

From: Heikki Linnakangas @ 2021-01-22 20:59 UTC (permalink / raw)

---
 src/backend/utils/sort/tuplesort.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c
index 14104643e78..aff2f201f52 100644
--- a/src/backend/utils/sort/tuplesort.c
+++ b/src/backend/utils/sort/tuplesort.c
@@ -2658,7 +2658,7 @@ merge_read_buffer_size(int64 avail_mem, int nInputTapes, int nInputRuns,
 	 * we derive the input buffer size from the amount of memory available,
 	 * and M and N.
 	 */
-	return (avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes;
+	return Max((avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes, 0);
 }
 
 /*
-- 
2.29.2


--------------631E0A48DCAEA386819DFCEC--





^ permalink  raw  reply  [nested|flat] 21+ messages in thread

* [PATCH v3 3/3] Fix sizing of tape read buffers.
@ 2021-01-22 20:59  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 21+ messages in thread

From: Heikki Linnakangas @ 2021-01-22 20:59 UTC (permalink / raw)

---
 src/backend/utils/sort/tuplesort.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c
index 14104643e78..aff2f201f52 100644
--- a/src/backend/utils/sort/tuplesort.c
+++ b/src/backend/utils/sort/tuplesort.c
@@ -2658,7 +2658,7 @@ merge_read_buffer_size(int64 avail_mem, int nInputTapes, int nInputRuns,
 	 * we derive the input buffer size from the amount of memory available,
 	 * and M and N.
 	 */
-	return (avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes;
+	return Max((avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes, 0);
 }
 
 /*
-- 
2.29.2


--------------631E0A48DCAEA386819DFCEC--





^ permalink  raw  reply  [nested|flat] 21+ messages in thread

* [PATCH v3 3/3] Fix sizing of tape read buffers.
@ 2021-01-22 20:59  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 21+ messages in thread

From: Heikki Linnakangas @ 2021-01-22 20:59 UTC (permalink / raw)

---
 src/backend/utils/sort/tuplesort.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c
index 14104643e78..aff2f201f52 100644
--- a/src/backend/utils/sort/tuplesort.c
+++ b/src/backend/utils/sort/tuplesort.c
@@ -2658,7 +2658,7 @@ merge_read_buffer_size(int64 avail_mem, int nInputTapes, int nInputRuns,
 	 * we derive the input buffer size from the amount of memory available,
 	 * and M and N.
 	 */
-	return (avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes;
+	return Max((avail_mem - TAPE_BUFFER_OVERHEAD * nOutputTapes) / nInputTapes, 0);
 }
 
 /*
-- 
2.29.2


--------------631E0A48DCAEA386819DFCEC--





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2021-01-22 20:59 [PATCH v3 3/3] Fix sizing of tape read buffers. Heikki Linnakangas <[email protected]>
2021-01-22 20:59 [PATCH v3 3/3] Fix sizing of tape read buffers. Heikki Linnakangas <[email protected]>
2021-01-22 20:59 [PATCH v3 3/3] Fix sizing of tape read buffers. Heikki Linnakangas <[email protected]>
2021-01-22 20:59 [PATCH v3 3/3] Fix sizing of tape read buffers. Heikki Linnakangas <[email protected]>
2021-01-22 20:59 [PATCH v3 3/3] Fix sizing of tape read buffers. Heikki Linnakangas <[email protected]>
2021-01-22 20:59 [PATCH v3 3/3] Fix sizing of tape read buffers. Heikki Linnakangas <[email protected]>
2021-01-22 20:59 [PATCH v3 3/3] Fix sizing of tape read buffers. Heikki Linnakangas <[email protected]>
2021-01-22 20:59 [PATCH v3 3/3] Fix sizing of tape read buffers. Heikki Linnakangas <[email protected]>
2021-01-22 20:59 [PATCH v3 3/3] Fix sizing of tape read buffers. Heikki Linnakangas <[email protected]>
2021-01-22 20:59 [PATCH v3 3/3] Fix sizing of tape read buffers. Heikki Linnakangas <[email protected]>
2021-01-22 20:59 [PATCH v3 3/3] Fix sizing of tape read buffers. Heikki Linnakangas <[email protected]>
2021-01-22 20:59 [PATCH v3 3/3] Fix sizing of tape read buffers. Heikki Linnakangas <[email protected]>
2021-01-22 20:59 [PATCH v3 3/3] Fix sizing of tape read buffers. Heikki Linnakangas <[email protected]>
2021-01-22 20:59 [PATCH v3 3/3] Fix sizing of tape read buffers. Heikki Linnakangas <[email protected]>
2021-01-22 20:59 [PATCH v3 3/3] Fix sizing of tape read buffers. Heikki Linnakangas <[email protected]>
2021-01-22 20:59 [PATCH v3 3/3] Fix sizing of tape read buffers. Heikki Linnakangas <[email protected]>
2021-01-22 20:59 [PATCH v3 3/3] Fix sizing of tape read buffers. Heikki Linnakangas <[email protected]>
2021-01-22 20:59 [PATCH v3 3/3] Fix sizing of tape read buffers. Heikki Linnakangas <[email protected]>
2021-01-22 20:59 [PATCH v3 3/3] Fix sizing of tape read buffers. Heikki Linnakangas <[email protected]>
2021-01-22 20:59 [PATCH v3 3/3] Fix sizing of tape read buffers. Heikki Linnakangas <[email protected]>
2021-01-22 20:59 [PATCH v3 3/3] Fix sizing of tape read buffers. Heikki Linnakangas <[email protected]>

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