Doc: further clarify libpq's description of connection string URIs.

Break the synopsis into named parts to make it less confusing.
Make more than zero effort at applying SGML markup.  Do a bit
of copy-editing of nearby text.

The synopsis revision is by Alvaro Herrera and Paul Förster,
the rest is my fault.  Back-patch to v10 where multi-host
connection strings appeared.

Discussion: https://postgr.es/m/6E752D6B-487C-463E-B6E2-C32E7FB007EA@gmail.com
This commit is contained in:
Tom Lane 2021-02-26 15:24:00 -05:00
parent 49076fd3ba
commit 5744931830

View File

@ -865,7 +865,7 @@ PQsslKeyPassHook_OpenSSL_type PQgetSSLKeyPassHook_OpenSSL(void);
<para>
Several <application>libpq</application> functions parse a user-specified string to obtain
connection parameters. There are two accepted formats for these strings:
plain <literal>keyword = value</literal> strings
plain keyword/value strings
and URIs. URIs generally follow
<ulink url="https://tools.ietf.org/html/rfc3986">RFC
3986</ulink>, except that multi-host connection strings are allowed
@ -876,12 +876,14 @@ PQsslKeyPassHook_OpenSSL_type PQgetSSLKeyPassHook_OpenSSL(void);
<title>Keyword/Value Connection Strings</title>
<para>
In the first format, each parameter setting is in the form
<literal>keyword = value</literal>. Spaces around the equal sign are
In the keyword/value format, each parameter setting is in the form
<replaceable>keyword</replaceable> <literal>=</literal>
<replaceable>value</replaceable>, with space(s) between settings.
Spaces around a setting's equal sign are
optional. To write an empty value, or a value containing spaces, surround it
with single quotes, e.g., <literal>keyword = 'a value'</literal>. Single
quotes and backslashes within
the value must be escaped with a backslash, i.e., <literal>\'</literal> and
with single quotes, for example <literal>keyword = 'a value'</literal>.
Single quotes and backslashes within
a value must be escaped with a backslash, i.e., <literal>\'</literal> and
<literal>\\</literal>.
</para>
@ -904,7 +906,19 @@ host=localhost port=5432 dbname=mydb connect_timeout=10
<para>
The general form for a connection <acronym>URI</acronym> is:
<synopsis>
postgresql://[user[:password]@][host][:port][,...][/dbname][?param1=value1&amp;...]
postgresql://<optional><replaceable>userspec</replaceable>@</optional><optional><replaceable>hostspec</replaceable></optional><optional>/<replaceable>dbname</replaceable></optional><optional>?<replaceable>paramspec</replaceable></optional>
<phrase>where <replaceable>userspec</replaceable> is:</phrase>
<replaceable>user</replaceable><optional>:<replaceable>password</replaceable></optional>
<phrase>and <replaceable>hostspec</replaceable> is:</phrase>
<optional><replaceable>host</replaceable></optional><optional>:<replaceable>port</replaceable></optional><optional>,...</optional>
<phrase>and <replaceable>paramspec</replaceable> is:</phrase>
<replaceable>name</replaceable>=<replaceable>value</replaceable><optional>&amp;...</optional>
</synopsis>
</para>
@ -977,7 +991,8 @@ postgresql://%2Fvar%2Flib%2Fpostgresql/dbname
port component, in a single URI. A URI of the form
<literal>postgresql://host1:port1,host2:port2,host3:port3/</literal>
is equivalent to a connection string of the form
<literal>host=host1,host2,host3 port=port1,port2,port3</literal>. Each
<literal>host=host1,host2,host3 port=port1,port2,port3</literal>.
As further described below, each
host will be tried in turn until a connection is successfully established.
</para>
</sect3>
@ -988,8 +1003,8 @@ postgresql://%2Fvar%2Flib%2Fpostgresql/dbname
<para>
It is possible to specify multiple hosts to connect to, so that they are
tried in the given order. In the Keyword/Value format, the <literal>host</literal>,
<literal>hostaddr</literal>, and <literal>port</literal> options accept a comma-separated
list of values. The same number of elements must be given in each
<literal>hostaddr</literal>, and <literal>port</literal> options accept comma-separated
lists of values. The same number of elements must be given in each
option that is specified, such
that e.g., the first <literal>hostaddr</literal> corresponds to the first host name,
the second <literal>hostaddr</literal> corresponds to the second host name, and so
@ -999,7 +1014,7 @@ postgresql://%2Fvar%2Flib%2Fpostgresql/dbname
<para>
In the connection URI format, you can list multiple <literal>host:port</literal> pairs
separated by commas, in the <literal>host</literal> component of the URI.
separated by commas in the <literal>host</literal> component of the URI.
</para>
<para>