From: Tom Lane <tgl@sss.pgh.pa.us>
To: Masahiko Sawada <sawada.mshk@gmail.com>
cc: exclusion@gmail.com, Tomas Vondra <tomas.vondra@enterprisedb.com>,
        pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #17969: Assert failed in bloom_init() when
 false_positive_rate = 0.25
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References: <17969-a6c54de48026d694@postgresql.org>
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Comments: In-reply-to Masahiko Sawada <sawada.mshk@gmail.com>
	message dated "Fri, 16 Jun 2023 11:18:30 +0900"
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Date: Thu, 15 Jun 2023 22:23:52 -0400
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Masahiko Sawada <sawada.mshk@gmail.com> writes:
> It seems that the minimum false positive rate also doesn't work:

> postgres(1:3419179)=# create table t (a int);
> CREATE TABLE
> postgres(1:3419179)=# create index t_idx on t using brin (a
> int4_bloom_ops (false_positive_rate = 0.0001));
> CREATE INDEX
> postgres(1:3419179)=# insert into t values (1);
> 2023-06-16 11:14:01.349 JST [3419179] ERROR:  the bloom filter is too
> large (8924 > 8144)
> 2023-06-16 11:14:01.349 JST [3419179] STATEMENT:  insert into t values (1);
> ERROR:  the bloom filter is too large (8924 > 8144)

Hmm, but it would work with a larger page size, right?  If so
I'm disinclined to move the minimum.  What I don't like about
the above is that the failure doesn't occur until you actually
insert an index entry.  Is there a way to check for this at
CREATE INDEX time?

			regards, tom lane