This commit documents rounding of "length" parameter and absence of support
for unique indexes and NULLs searching. Backpatch to 9.6 where contrib/bloom
was introduced.
Discussion: https://postgr.es/m/CAF4Au4wPQQ7EHVSnzcLjsbY3oLSzVk6UemZLD1Sbmwysy3R61g%40mail.gmail.com
Author: Oleg Bartunov with minor editorialization by me
Backpatch-through: 9.6
<term><literal>length</></term>
<listitem>
<para>
- Length of each signature (index entry) in bits. The default
- is <literal>80</> bits and maximum is <literal>4096</>.
+ Length of each signature (index entry) in bits, it is rounded up to the nearest
+ multiple of <literal>16</>. The default is <literal>80</> bits and maximum is <literal>4096</literal>.
</para>
</listitem>
</varlistentry>
operations in the future.
</para>
</listitem>
+
+ <listitem>
+ <para>
+ <literal>bloom</literal> access method doesn't support
+ <literal>UNIQUE</literal> indexes.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ <literal>bloom</literal> access method doesn't support searching for
+ <literal>NULL</literal> values.
+ </para>
+ </listitem>
</itemizedlist>
</para>
</sect2>