File tree Expand file tree Collapse file tree 12 files changed +23
-18
lines changed Expand file tree Collapse file tree 12 files changed +23
-18
lines changed Original file line number Diff line number Diff line change @@ -1036,7 +1036,7 @@ ____________________________________________________________________________-->
1036
1036
在 MVCC下B-Tree索引不能直接感知,同一个逻辑表行可能存在多个现存版本;对于一个索引来说,每个元组都是一个需要其自己的索引条目的独立的对象。
1037
1037
<quote>Version churn</quote>元组有时可能会积累,并且对查询延迟和吞吐量产生影响。
1038
1038
这通常发生在<command>UPDATE</command>较为繁重的工作负载中,其中大多数单独的更新不能应用<acronym>HOT</acronym>优化。
1039
- 在<command>UPDATE</command>更改仅一个被一个索引覆盖的列期间,<emphasis>总是</emphasis> 需要一个新的索引元组 &mdash; 一个用于表上的<emphasis>each and every</emphasis>索引。
1039
+ 在<command>UPDATE</command>更改仅一个被一个索引覆盖的列期间,<emphasis>总是</emphasis> 需要一个新的索引元组 — 一个用于表上的<emphasis>each and every</emphasis>索引。
1040
1040
特别注意,这包括没有被<command>UPDATE</command>进行<quote>logically modified</quote>的索引。
1041
1041
所有索引将需要一个后继的物理索引元组,用于指向表中的最新版本。
1042
1042
每个索引中的每个新元组通常需要与原始的<quote>updated</quote>元组共存很短一段时间(通常直到<command>UPDATE</command>事务提交后不久)。
Original file line number Diff line number Diff line change @@ -25284,7 +25284,7 @@ ____________________________________________________________________________-->
25284
25284
</para>
25285
25285
____________________________________________________________________________-->
25286
25286
<para>
25287
- <structname>pg_stats_ext_exprs</structname>也被设计为以比底层目录更方便阅读的格式来展现信息 &mdash; 相应的代价是当 <structname>pg_statistic_ext</structname>中的统计信息的结构发生改变时,必须扩展其模式。
25287
+ <structname>pg_stats_ext_exprs</structname>也被设计为以比底层目录更方便阅读的格式来展现信息 — 相应的代价是当 <structname>pg_statistic_ext</structname>中的统计信息的结构发生改变时,必须扩展其模式。
25288
25288
</para>
25289
25289
25290
25290
<table>
@@ -25595,7 +25595,7 @@ ____________________________________________________________________________-->
25595
25595
<para>
25596
25596
表达式的值的物理行排序和逻辑排序之间的统计相关性。这个范围从-1 到 +1。
25597
25597
当该值接近-1或+1时,对表达式的索引扫描预计要比接近零的时候更便宜,因为减少了对磁盘的随机访问。
25598
- (如果表达式的数据类型没有<literal><</literal>< 操作符,则该表达式为空。)
25598
+ (如果表达式的数据类型没有<literal><</literal>操作符,则该表达式为空。)
25599
25599
</para></entry>
25600
25600
</row>
25601
25601
Original file line number Diff line number Diff line change @@ -692,7 +692,7 @@ hostnogssenc <replaceable>database</replaceable> <replaceable>user</replaceabl
692
692
format. To see the <literal>DN</literal> of a client certificate
693
693
in this format, do
694
694
<programlisting>
695
- openssl x509 -in myclient.crt -noout -- subject -nameopt RFC2253 | sed "s/^subject=//"
695
+ openssl x509 -in myclient.crt -noout -− subject -nameopt RFC2253 | sed "s/^subject=//"
696
696
</programlisting>
697
697
Care needs to be taken when using this option, especially when using
698
698
regular expression matching against the <literal>DN</literal>.
Original file line number Diff line number Diff line change @@ -1885,7 +1885,7 @@ ____________________________________________________________________________-->
1885
1885
<filename>FILE:/usr/local/pgsql/etc/krb5.keytab</filename>
1886
1886
(where the directory part is whatever was specified
1887
1887
as <varname>sysconfdir</varname> at build time; use
1888
- <literal>pg_config -- sysconfdir</literal> to determine that).
1888
+ <literal>pg_config -− sysconfdir</literal> to determine that).
1889
1889
If this parameter is set to an empty string, it is ignored and a
1890
1890
system-dependent default is used.
1891
1891
This parameter can only be set in the
Original file line number Diff line number Diff line change @@ -253,7 +253,9 @@ ____________________________________________________________________________-->
253
253
<primary>B-Tree</primary>
254
254
<see>index</see>
255
255
</indexterm>
256
- B-tree可以在可排序数据上的处理等值和范围查询。特别地,<productname>PostgreSQL</productname>的查询规划器会在任何一种涉及到以下操作符的已索引列上考虑使用B-tree索引:
256
+
257
+ <para>
258
+ B-tree可以在可排序数据上的处理等值和范围查询。特别地,<productname>PostgreSQL</productname>的查询规划器会在任何一种涉及到以下操作符的已索引列上考虑使用B-tree索引:
257
259
258
260
<synopsis>
259
261
< <= = >= >
@@ -327,6 +329,7 @@ ____________________________________________________________________________-->
327
329
<primary>hash</primary>
328
330
<see>index</see>
329
331
</indexterm>
332
+ <para>
330
333
HASH索引存储一个由索引列计算出的32位的hash code值。因此,Hash索引只能处理简单等值比较。每当索引列涉及到等值操作符的比较时,查询规划器将会使用Hash索引。
331
334
<synopsis>
332
335
=
@@ -603,6 +606,8 @@ ____________________________________________________________________________-->
603
606
<primary>BRIN</primary>
604
607
<see>index</see>
605
608
</indexterm>
609
+
610
+ <para>
606
611
BRIN 索引(块范围索引的缩写)存储有关存放在一个表的连续物理块范围上的值摘要信息。因此,那些值和table中物理行存放顺序相关性更好的列更高效。与 GiST、SP-GiST 和 GIN 相似,BRIN 可以支持很多种不同的索引策略,并且可以与一个 BRIN 索引配合使用的特定操作符取决于索引策略。对于具有线性排序顺序的数据类型,被索引的数据对应于每个块范围的列中值的最小值和最大值,使用这些操作符来支持用到索引的查询:
607
612
608
613
<synopsis>
Original file line number Diff line number Diff line change @@ -4082,7 +4082,7 @@ make PG_SYSROOT=<replaceable>/desired/path</replaceable> all
4082
4082
</programlisting>
4083
4083
To find out the appropriate path on your machine, run
4084
4084
<programlisting>
4085
- xcrun -- show-sdk-path
4085
+ xcrun -− show-sdk-path
4086
4086
</programlisting>
4087
4087
Note that building an extension using a different sysroot version than
4088
4088
was used to build the core server is not really recommended; in the
Original file line number Diff line number Diff line change @@ -360,7 +360,7 @@ ____________________________________________________________________________-->
360
360
</varlistentry>
361
361
362
362
<varlistentry>
363
- <term><option>-- no-instructions</option></term>
363
+ <term><option>-− no-instructions</option></term>
364
364
<listitem>
365
365
<para>
366
366
By default, <command>initdb</command> will write instructions for how
Original file line number Diff line number Diff line change @@ -257,7 +257,7 @@ ____________________________________________________________________________-->
257
257
tablespaces, the main data directory will be placed in the
258
258
target directory, but all other tablespaces will be placed
259
259
in the same absolute path as they have on the source server.
260
- (See <option>-- tablespace-mapping</option> to change that.)
260
+ (See <option>-− tablespace-mapping</option> to change that.)
261
261
</para>
262
262
<para>
263
263
This is the default format.
@@ -297,7 +297,7 @@ ____________________________________________________________________________-->
297
297
<para>
298
298
Creates a
299
299
<link linkend="file-standby-signal"><filename>standby.signal</filename></link>
300
- <indexterm><primary><filename>standby.signal</filename></primary><secondary>pg_basebackup -- write-recovery-conf</secondary></indexterm>
300
+ <indexterm><primary><filename>standby.signal</filename></primary><secondary>pg_basebackup -− write-recovery-conf</secondary></indexterm>
301
301
file and appends
302
302
connection settings to the <filename>postgresql.auto.conf</filename>
303
303
file in the target directory (or within the base archive file when
Original file line number Diff line number Diff line change @@ -1186,13 +1186,13 @@ ____________________________________________________________________________-->
1186
1186
<listitem>
1187
1187
<para>
1188
1188
Require that each
1189
- extension (<option>-e</option>/<option>-- extension</option>),
1190
- schema (<option>-n</option>/<option>-- schema</option>) and
1191
- table (<option>-t</option>/<option>-- table</option>) qualifier
1189
+ extension (<option>-e</option>/<option>-− extension</option>),
1190
+ schema (<option>-n</option>/<option>-− schema</option>) and
1191
+ table (<option>-t</option>/<option>-− table</option>) qualifier
1192
1192
match at least one extension/schema/table in the database to be dumped.
1193
1193
Note that if none of the extension/schema/table qualifiers find
1194
1194
matches, <application>pg_dump</application> will generate an error
1195
- even without <option>-- strict-names</option>.
1195
+ even without <option>-− strict-names</option>.
1196
1196
</para>
1197
1197
<para>
1198
1198
This option has no effect
Original file line number Diff line number Diff line change @@ -1354,7 +1354,7 @@ ____________________________________________________________________________-->
1354
1354
如果指定了<replaceable class="parameter">join_using_alias</replaceable>名称,它为连接列提供表的别名。
1355
1355
只有<literal>USING</literal>子句中列出的连接列可以通过此名称寻址。
1356
1356
与常规的<replaceable class="parameter">alias</replaceable>不同,这不会隐藏从查询的其余部分的连接表的名称。
1357
- 也不像常规的<replaceable class="parameter">alias</replaceable>,你不能写列别名列表&mdash;
1357
+ 也不像常规的<replaceable class="parameter">alias</replaceable>,你不能写列别名列表—
1358
1358
连接列的输出名称与它们在<literal>USING</literal>列表中出现的名称相同。
1359
1359
</para>
1360
1360
</listitem>
You can’t perform that action at this time.
0 commit comments