Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

Appearance settings

Commit f739992

Browse filesBrowse files
committed
tablefunc: Reject negative number of tuples passed to normal_rand()
The function converted the first argument i.e. the number of tuples to return into an unsigned integer which turns out to be huge number when a negative value is passed. This causes the function to take much longer time to execute. Instead, reject a negative value. (If someone really wants to generate many more result rows, they should consider adding a bigint or numeric variant.) While at it, improve SQL test to test the number of tuples returned by this function. Author: Ashutosh Bapat <ashutosh.bapat@2ndquadrant.com> Discussion: https://www.postgresql.org/message-id/CAG-ACPW3PUUmSnM6cLa9Rw4BEC5cEMKjX8Gogc8gvQcT3cYA1A@mail.gmail.com
1 parent 2fbd786 commit f739992
Copy full SHA for f739992

File tree

Expand file treeCollapse file tree

3 files changed

+18
-6
lines changed
Filter options
Expand file treeCollapse file tree

3 files changed

+18
-6
lines changed

‎contrib/tablefunc/expected/tablefunc.out

Copy file name to clipboardExpand all lines: contrib/tablefunc/expected/tablefunc.out
+7-4Lines changed: 7 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -3,12 +3,15 @@ CREATE EXTENSION tablefunc;
33
-- normal_rand()
44
-- no easy way to do this for regression testing
55
--
6-
SELECT avg(normal_rand)::int FROM normal_rand(100, 250, 0.2);
7-
avg
8-
-----
9-
250
6+
SELECT avg(normal_rand)::int, count(*) FROM normal_rand(100, 250, 0.2);
7+
avg | count
8+
-----+-------
9+
250 | 100
1010
(1 row)
1111

12+
-- negative number of tuples
13+
SELECT avg(normal_rand)::int, count(*) FROM normal_rand(-1, 250, 0.2);
14+
ERROR: number of rows cannot be negative
1215
--
1316
-- crosstab()
1417
--

‎contrib/tablefunc/sql/tablefunc.sql

Copy file name to clipboardExpand all lines: contrib/tablefunc/sql/tablefunc.sql
+3-1Lines changed: 3 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -4,7 +4,9 @@ CREATE EXTENSION tablefunc;
44
-- normal_rand()
55
-- no easy way to do this for regression testing
66
--
7-
SELECT avg(normal_rand)::int FROM normal_rand(100, 250, 0.2);
7+
SELECT avg(normal_rand)::int, count(*) FROM normal_rand(100, 250, 0.2);
8+
-- negative number of tuples
9+
SELECT avg(normal_rand)::int, count(*) FROM normal_rand(-1, 250, 0.2);
810

911
--
1012
-- crosstab()

‎contrib/tablefunc/tablefunc.c

Copy file name to clipboardExpand all lines: contrib/tablefunc/tablefunc.c
+8-1Lines changed: 8 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -184,6 +184,8 @@ normal_rand(PG_FUNCTION_ARGS)
184184
/* stuff done only on the first call of the function */
185185
if (SRF_IS_FIRSTCALL())
186186
{
187+
int32 num_tuples;
188+
187189
/* create a function context for cross-call persistence */
188190
funcctx = SRF_FIRSTCALL_INIT();
189191

@@ -193,7 +195,12 @@ normal_rand(PG_FUNCTION_ARGS)
193195
oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
194196

195197
/* total number of tuples to be returned */
196-
funcctx->max_calls = PG_GETARG_UINT32(0);
198+
num_tuples = PG_GETARG_INT32(0);
199+
if (num_tuples < 0)
200+
ereport(ERROR,
201+
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
202+
errmsg("number of rows cannot be negative")));
203+
funcctx->max_calls = num_tuples;
197204

198205
/* allocate memory for user context */
199206
fctx = (normal_rand_fctx *) palloc(sizeof(normal_rand_fctx));

0 commit comments

Comments
0 (0)
Morty Proxy This is a proxified and sanitized view of the page, visit original site.