diff --git a/doc/src/sgml/bloom.sgml b/doc/src/sgml/bloom.sgml
index c207e6dd685..7349095269b 100644
--- a/doc/src/sgml/bloom.sgml
+++ b/doc/src/sgml/bloom.sgml
@@ -8,32 +8,32 @@
- bloom> is a contrib which implements index access method. It comes
- as example of custom access methods and generic WAL records usage. But it
- is also useful itself.
+ bloom> is a module which implements an index access method. It comes
+ as an example of custom access methods and generic WAL records usage. But it
+ is also useful in itself.
Introduction
- Implementation of
+ The implementation of a
Bloom filter
- allows fast exclusion of non-candidate tuples.
- Since signature is a lossy representation of all indexed attributes,
- search results should be rechecked using heap information.
- User can specify signature length (in uint16, default is 5) and the number of
- bits, which can be setted, per attribute (1 < colN < 2048).
+ allows fast exclusion of non-candidate tuples via signatures.
+ Since a signature is a lossy representation of all indexed attributes,
+ search results must be rechecked using heap information.
+ The user can specify signature length (in uint16, default is 5) and the
+ number of bits, which can be set per attribute (1 < colN < 2048).
- This index is useful if table has many attributes and queries can include
- their arbitary combinations. Traditional btree> index is faster
- than bloom index, but it'd require too many indexes to support all possible
- queries, while one need only one bloom index. Bloom index supports only
- equality comparison. Since it's a signature file, not a tree, it always
- should be readed fully, but sequentially, so index search performance is
- constant and doesn't depend on a query.
+ This index is useful if a table has many attributes and queries include
+ arbitrary combinations of them. A traditional btree> index is
+ faster than a bloom index, but it can require many indexes to support all
+ possible queries where one needs only a single bloom index. A Bloom index
+ supports only equality comparison. Since it's a signature file, and not a
+ tree, it always must be read fully, but sequentially, so that index search
+ performance is constant and doesn't depend on a query.
@@ -41,7 +41,8 @@
Parameters
- bloom> indexes accept following parameters in WITH>
+ bloom> indexes accept the following parameters in the
+ WITH>
clause.
@@ -71,7 +72,7 @@
Examples
- Example of index definition is given below.
+ An example of an index definition is given below.
@@ -80,12 +81,12 @@ CREATE INDEX bloomidx ON tbloom(i1,i2,i3)
- Here, we create bloom index with signature length 80 bits and attributes
- i1, i2 mapped to 2 bits, attribute i3 - to 4 bits.
+ Here, we created a bloom index with a signature length of 80 bits,
+ and attributes i1 and i2 mapped to 2 bits, and attribute i3 to 4 bits.
- Example of index definition and usage is given below.
+ Here is a fuller example of index definition and usage:
@@ -142,7 +143,7 @@ SELECT pg_relation_size('btree_idx');
- Btree index will be not used for this query.
+ A btree index will be not used for this query.
@@ -162,10 +163,10 @@ SELECT pg_relation_size('btree_idx');
Opclass interface
- Bloom opclass interface is simple. It requires 1 supporting function:
- hash function for indexing datatype. And it provides 1 search operator:
- equality operator. The example below shows opclass> definition
- for text> datatype.
+ The Bloom opclass interface is simple. It requires 1 supporting function:
+ a hash function for the indexing datatype. It provides 1 search operator:
+ the equality operator. The example below shows opclass>
+ definition for text> datatype.
@@ -183,16 +184,16 @@ DEFAULT FOR TYPE text USING bloom AS
- For now, only opclasses for int4>, text> comes
- with contrib. However, users may define more of them.
+ For now, only opclasses for int4>, text> come
+ with the module. However, users may define more of them.
- Only = operator is supported for search now. But it's
- possible to add support of arrays with contains and intersection
- operations in future.
+ Only the = operator is supported for search at the
+ moment. But it's possible to add support for arrays with contains and
+ intersection operations in the future.
@@ -203,15 +204,18 @@ DEFAULT FOR TYPE text USING bloom AS
Authors
- Teodor Sigaev teodor@postgrespro.ru, Postgres Professional, Moscow, Russia
+ Teodor Sigaev teodor@postgrespro.ru,
+ Postgres Professional, Moscow, Russia
- Alexander Korotkov a.korotkov@postgrespro.ru, Postgres Professional, Moscow, Russia
+ Alexander Korotkov a.korotkov@postgrespro.ru,
+ Postgres Professional, Moscow, Russia
- Oleg Bartunov obartunov@postgrespro.ru, Postgres Professional, Moscow, Russia
+ Oleg Bartunov obartunov@postgrespro.ru,
+ Postgres Professional, Moscow, Russia