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Instead of immediately PQfinish'ing a dead connection, save it aside so that we can still extract its parameters for \connect attempts. (This works because PQconninfo doesn't care whether the PGconn is in CONNECTION_BAD state.) This allows developers to reconnect with just \c after a database crash and restart. It's tempting to use the same approach instead of closing the old connection after a failed non-interactive \connect command. However, that would not be very safe: consider a script containing \c db1 user1 live_server \c db2 user2 dead_server \c db3 The script would be expecting to connect to db3 at dead_server, but if we re-use parameters from the first connection then it might successfully connect to db3 at live_server. This'd defeat the goal of not letting a script accidentally execute commands against the wrong database. Discussion: https://postgr.es/m/38464.1603394584@sss.pgh.pa.us
<!-- doc/src/sgml/README.links -->
Linking within DocBook documents can be confusing, so here is a summary:
Intra-document Linking
----------------------
<xref>
use to get chapter/section number from the title of the target
link, or xreflabel if defined at the target, or refentrytitle if target
is a refentry; has no close tag
http://www.oasis-open.org/docbook/documentation/reference/html/xref.html
linkend=
controls the target of the link/xref, required
endterm=
for <xref>, allows the text of the link/xref to be taken from a
different link target title
<link>
use to supply text for the link, only uses linkend, requires </link>
http://www.oasis-open.org/docbook/documentation/reference/html/link.html
External Linking
----------------
<ulink>
like <link>, but uses a URL (not a document target); requires
</ulink>; if no text is specified, the URL appears as the link
text
http://www.oasis-open.org/docbook/documentation/reference/html/ulink.html
url=
used by <ulink> to specify the URL, required
Guidelines
----------
- For an internal link, if you want to supply text, use <link>, else
<xref>.
- Specific nouns like GUC variables, SQL commands, and contrib modules
usually have xreflabels.
- For an external link, use <ulink>, with or without link text.
- xreflabels added to tags prevent the chapter/section for id's from being
referenced; only the xreflabel is accessible. Therefore, use xreflabels
only when linking is common, and chapter/section information is unneeded.