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Improve wordings by David Fuhry <dfuhry@cs.kent.edu>

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This commit is contained in:
Teodor Sigaev 2006-09-18 12:11:36 +00:00
parent 18a963778a
commit bcbb402e31
5 changed files with 34 additions and 31 deletions
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4
doc/src/sgml/config.sgml
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@ -1,4 +1,4 @@
<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.87 2006/09/16 00:30:12 momjian Exp $ -->
<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.88 2006/09/18 12:11:36 teodor Exp $ -->
<chapter Id="runtime-config">
<title>Server Configuration</title>
@ -2180,7 +2180,7 @@ SELECT * FROM parent WHERE key = 2400;
</indexterm>
<listitem>
<para>
Soft upper limit of the size of the returned set by GIN index. For more
Soft upper limit of the size of the set returned by GIN index. For more
information see <xref linkend="gin-tips">.
</para>
</listitem>

37
doc/src/sgml/gin.sgml
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@ -1,4 +1,4 @@
<!-- $PostgreSQL: pgsql/doc/src/sgml/gin.sgml,v 2.3 2006/09/14 21:15:07 tgl Exp $ -->
<!-- $PostgreSQL: pgsql/doc/src/sgml/gin.sgml,v 2.4 2006/09/18 12:11:36 teodor Exp $ -->
<chapter id="GIN">
<title>GIN Indexes</title>
@ -14,7 +14,7 @@
<para>
<acronym>GIN</acronym> stands for Generalized Inverted Index. It is
an index structure storing a set of (key, posting list) pairs, where
'posting list' is a set of rows in which the key occurs. The
'posting list' is a set of rows in which the key occurs. Each
row may contain many keys.
</para>
@ -104,7 +104,8 @@
<listitem>
<para>
Returns an array of keys of the query to be executed. n contains
strategy number of operation (see <xref linkend="xindex-strategies">).
the strategy number of the operation
(see <xref linkend="xindex-strategies">).
Depending on n, query may be different type.
</para>
</listitem>
@ -114,9 +115,9 @@
<term>bool consistent( bool check[], StrategyNumber n, Datum query)</term>
<listitem>
<para>
Returns TRUE if indexed value satisfies query qualifier with strategy n
(or may satisfy in case of RECHECK mark in operator class).
Each element of the check array is TRUE if indexed value has a
Returns TRUE if the indexed value satisfies the query qualifier with
strategy n (or may satisfy in case of RECHECK mark in operator class).
Each element of the check array is TRUE if the indexed value has a
corresponding key in the query: if (check[i] == TRUE ) the i-th key of
the query is present in the indexed value.
</para>
@ -135,10 +136,10 @@
<term>Create vs insert</term>
<listitem>
<para>
In most cases, insertion into <acronym>GIN</acronym> index is slow because
many GIN keys may be inserted for each table row. So, when loading data
in bulk it may be useful to drop index and recreate it
after the data is loaded in the table.
In most cases, insertion into <acronym>GIN</acronym> index is slow
due to the likelihood of many keys being inserted for each value.
So, for bulk insertions into a table it is advisable to to drop the GIN
index and recreate it after finishing bulk insertion.
</para>
</listitem>
</varlistentry>
@ -147,7 +148,7 @@
<term>gin_fuzzy_search_limit</term>
<listitem>
<para>
The primary goal of development <acronym>GIN</acronym> indices was
The primary goal of developing <acronym>GIN</acronym> indices was
support for highly scalable, full-text search in
<productname>PostgreSQL</productname> and there are often situations when
a full-text search returns a very large set of results. Since reading
@ -158,7 +159,7 @@
<para>
Such queries usually contain very frequent words, so the results are not
very helpful. To facilitate execution of such queries
<acronym>GIN</acronym> has a configurable soft upper limit of the size
<acronym>GIN</acronym> has a configurable soft upper limit of the size
of the returned set, determined by the
<varname>gin_fuzzy_search_limit</varname> GUC variable. It is set to 0 by
default (no limit).
@ -182,16 +183,16 @@
<title>Limitations</title>
<para>
<acronym>GIN</acronym> doesn't support full scan of index due to it's
extremely inefficiency: because of a lot of keys per value,
<acronym>GIN</acronym> doesn't support full index scans due to their
extremely inefficiency: because there are often many keys per value,
each heap pointer will returned several times.
</para>
<para>
When extractQuery returns zero number of keys, <acronym>GIN</acronym> will
emit a error: for different opclass and strategy semantic meaning of void
query may be different (for example, any array contains void array,
but they aren't overlapped with void one), and <acronym>GIN</acronym> can't
When extractQuery returns zero keys, <acronym>GIN</acronym> will emit a
error: for different opclasses and strategies the semantic meaning of a void
query may be different (for example, any array contains the void array,
but they don't overlap the void array), and <acronym>GIN</acronym> can't
suggest reasonable answer.
</para>

6
doc/src/sgml/indices.sgml
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@ -1,4 +1,4 @@
<!-- $PostgreSQL: pgsql/doc/src/sgml/indices.sgml,v 1.63 2006/09/16 00:30:14 momjian Exp $ -->
<!-- $PostgreSQL: pgsql/doc/src/sgml/indices.sgml,v 1.64 2006/09/18 12:11:36 teodor Exp $ -->
<chapter id="indexes">
<title id="indexes-title">Indexes</title>
@ -248,7 +248,7 @@ CREATE INDEX <replaceable>name</replaceable> ON <replaceable>table</replaceable>
<see>index</see>
</indexterm>
GIN is a inverted index and it's usable for values which have more
than one key, arrays for example. Like to GiST, GIN may support
than one key, arrays for example. Like GiST, GIN may support
many different user-defined indexing strategies and the particular
operators with which a GIN index can be used vary depending on the
indexing strategy.
@ -266,7 +266,7 @@ CREATE INDEX <replaceable>name</replaceable> ON <replaceable>table</replaceable>
(See <xref linkend="functions-array"> for the meaning of
these operators.)
Another GIN operator classes are available in the <literal>contrib</>
Other GIN operator classes are available in the <literal>contrib</>
tsearch2 and intarray modules. For more information see <xref linkend="GIN">.
</para>
</sect1>

12
doc/src/sgml/mvcc.sgml
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@ -1,4 +1,4 @@
<!-- $PostgreSQL: pgsql/doc/src/sgml/mvcc.sgml,v 2.61 2006/09/17 22:50:31 tgl Exp $ -->
<!-- $PostgreSQL: pgsql/doc/src/sgml/mvcc.sgml,v 2.62 2006/09/18 12:11:36 teodor Exp $ -->
<chapter id="mvcc">
<title>Concurrency Control</title>
@ -993,10 +993,12 @@ UPDATE accounts SET balance = balance - 100.00 WHERE acctnum = 22222;
</term>
<listitem>
<para>
Short-term share/exclusive page-level locks are used for
read/write access. Locks are released immediately after each
index row is fetched or inserted. However, note that a GIN index
usually requires several inserts for each table row.
Short-term share/exclusive page-level locks are used for
read/write access. Locks are released immediately after each
index row is fetched or inserted. But note that a GIN-indexed
value insertion usually produces several index key insertions
per row, so GIN may do substantial work for a single value's
insertion.
</para>
</listitem>
</varlistentry>

6
doc/src/sgml/xindex.sgml
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@ -1,4 +1,4 @@
<!-- $PostgreSQL: pgsql/doc/src/sgml/xindex.sgml,v 1.48 2006/09/16 00:30:16 momjian Exp $ -->
<!-- $PostgreSQL: pgsql/doc/src/sgml/xindex.sgml,v 1.49 2006/09/18 12:11:36 teodor Exp $ -->
<sect1 id="xindex">
<title>Interfacing Extensions To Indexes</title>
@ -243,8 +243,8 @@
</table>
<para>
GIN indexes are similar to GiST in flexibility: it hasn't a fixed set
of strategies. Instead, the <quote>consistency</> support routine
GIN indexes are similar to GiST's in flexibility: they don't have a fixed
et of strategies. Instead, the <quote>consistency</> support routine
interprets the strategy numbers accordingly with operator class
definition. As an example, strategies of operator class over arrays
is shown in <xref linkend="xindex-gin-array-strat-table">.