Enlarge assertion in bloom_init() for false_positive_rate

michaelpq · michaelpq · commit 4dccf9575369 · 2023-11-08T14:06:36.000+09:00
false_positive_rate is a parameter that can be set with the bloom opclass in BRIN, and setting it to a value of exactly 0.25 would trigger an assertion in the first INSERT done on the index with value set. The assertion changed here relied on BLOOM_{MIN|MAX}_FALSE_POSITIVE_RATE that are somewhat arbitrary values, and specifying an out-of-range value would also trigger a failure when defining such an index. So, as-is, the assertion was just doubling on the min-max check of the reloption. This is now enlarged to check that it is a correct percentage value, instead, based on a suggestion by Tom Lane. Author: Alexander Lakhin Reviewed-by: Tom Lane, Shihao Zhong Discussion: https://postgr.es/m/17969-a6c54de48026d694@postgresql.org Backpatch-through: 14
diff --git a/src/backend/access/brin/brin_bloom.c b/src/backend/access/brin/brin_bloom.c
@@ -279,8 +279,7 @@ bloom_init(int ndistinct, double false_positive_rate)
 	double		k;				/* number of hash functions */
 
 	Assert(ndistinct > 0);
-	Assert((false_positive_rate >= BLOOM_MIN_FALSE_POSITIVE_RATE) &&
-		   (false_positive_rate < BLOOM_MAX_FALSE_POSITIVE_RATE));
+	Assert(false_positive_rate > 0 && false_positive_rate < 1);
 
 	/* sizing bloom filter: -(n * ln(p)) / (ln(2))^2 */
 	nbits = ceil(-(ndistinct * log(false_positive_rate)) / pow(log(2.0), 2));
