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Diffstat (limited to 'doc/src/FAQ/FAQ.html')
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1 files changed, 31 insertions, 28 deletions
diff --git a/doc/src/FAQ/FAQ.html b/doc/src/FAQ/FAQ.html index 042a4984ee4..b8b24ccae02 100644 --- a/doc/src/FAQ/FAQ.html +++ b/doc/src/FAQ/FAQ.html @@ -14,7 +14,7 @@ alink="#0000ff"> <H1>Frequently Asked Questions (FAQ) for PostgreSQL</H1> - <P>Last updated: Sun Oct 13 22:49:56 EDT 2002</P> + <P>Last updated: Sun Oct 13 23:15:09 EDT 2002</P> <P>Current maintainer: Bruce Momjian (<A href= "mailto:pgman@candle.pha.pa.us">pgman@candle.pha.pa.us</A>)<BR> @@ -78,8 +78,8 @@ <A href="#3.7">3.7</A>) What debugging features are available?<BR> <A href="#3.8">3.8</A>) Why do I get <I>"Sorry, too many clients"</I> when trying to connect?<BR> - <A href="#3.9">3.9</A>) What are the <I>pg_sorttempNNN.NN</I> - files in my database directory?<BR> + <A href="#3.9">3.9</A>) What is in the <I>pgsql_tmp</I> + directory?<BR> <A href="#3.10">3.10</A>) Why do I need to do a dump and restore to upgrade PostgreSQL releases?<BR> @@ -250,10 +250,11 @@ <P>The database server can run on Windows NT and Win2k using Cygwin, the Cygnus Unix/NT porting library. See <I>pgsql/doc/FAQ_MSWIN</I> in the distribution or the MS Windows FAQ - at <A href="http://www.PostgreSQL.org/docs/faq-mswin.html">http://www.PostgreSQL.org/docs/faq-mswin.html</A>.</P> + at <A href="http://www.PostgreSQL.org/docs/faq-mswin.html"> + http://www.PostgreSQL.org/docs/faq-mswin.html</A>.</P> - <p>A native port to some Microsoft platforms is currently being worked - upon.</p> + <p>A native port to MS Win NT/2000/XP is currently being worked + on.</p> <H4><A name="1.5">1.5</A>) Where can I get PostgreSQL?</H4> @@ -484,7 +485,7 @@ PostgreSQL?</H4> <P>PostgreSQL has had a first-class infrastructure since we started - in 1994. This is all thanks to Marc Fournier, who has created + in 1996. This is all thanks to Marc Fournier, who has created and managed this infrastructure over the years.</P> <P>Quality infrastructure is very important to an open-source @@ -545,9 +546,9 @@ interface? A report generator? An embedded query language interface?</H4> - <P>We have a nice graphical user interface called PgAccess, which is - shipped as part of the distribution. PgAccess also has a report - generator. The Web page is <A href="http://www.pgaccess.org/">http://www.pgaccess.org/</A>.</P> + <P>We have a nice graphical user interface called PgAccess which can + also be used as a report generator. The Web page is + <A href="http://www.pgaccess.org/">http://www.pgaccess.org/</A>.</P> <P>We also include <I>ecpg</I>, which is an embedded SQL query language interface for C.</P> @@ -565,7 +566,7 @@ <LI>Java (jdbc)</LI> - <LI>Perl (DBD::Pg)</LI> + <LI>Perl (DBD::Pg and perl5)</LI> <LI>ODBC (odbc)</LI> @@ -578,7 +579,9 @@ <LI>PHP ('pg_' functions, Pear::DB)</LI> </UL> <P>Additional interfaces are available at - <a href="http://www.PostgreSQL.org/interfaces.html">http://www.PostgreSQL.org/interfaces.html</A>. + <a href="http://www.PostgreSQL.org/interfaces.html">http://www.PostgreSQL.org/interfaces.html</A> + and + <a href="http://gborg.PostgreSQL.org">http://gborg.PostgreSQL.org</A>. </P> <HR> @@ -765,8 +768,8 @@ the MaxBackendId constant in <I>include/storage/sinvaladt.h</I>.</P> - <H4><A name="3.9">3.9</A>) What are the <I>pg_tempNNN.NN</I> - files in my database directory?</H4> + <H4><A name="3.9">3.9</A>) What are the <I>pgsql_tmp</I> + directory?</H4> <P>They are temporary files generated by the query executor. For example, if a sort needs to be done to satisfy an <SMALL>ORDER @@ -774,10 +777,9 @@ <I>-S</I> parameter allows, then temporary files are created to hold the extra data.</P> - <P>The temporary files should be deleted automatically, but might - not if a backend crashes during a sort. If you have no backends - running at the time, it is safe to delete the pg_tempNNN.NN - files.</P> + <P>The temporary files are usually deleted automatically, but might + remain if a backend crashes during a sort. A stop and restart of the + <I>postmaster</I> will remove files from those directories.</P> <H4><A name="3.10">3.10</A>) Why do I need to do a dump and restore to upgrade between major PostgreSQL releases?</H4> @@ -790,10 +792,10 @@ data in a generic format that can then be loaded in using the new internal format.</P> - <p>In releases where the on-disk format does not change, the - <i>pg_upgrade</i> script can be used to upgrade without a dump/restore. - The release notes mention whether <i>pg_upgrade</i> is available for the - release.</p> + <P>In releases where the on-disk format does not change, the + <I>pg_upgrade</I> script can be used to upgrade without a dump/restore. + The release notes mention whether <I>pg_upgrade</I> is available for the + release.</P> <HR> @@ -831,8 +833,9 @@ <H4><A name="4.4">4.4</A>) How do you remove a column from a table?</H4> - <P>Prior to version 7.3, <SMALL>ALTER TABLE DROP COLUMN</SMALL> is not supported. - You can do this instead:</P> + <P>This functionality was added in release 7.3 with + <SMALL>ALTER TABLE DROP COLUMN</SMALL>. In earlier versions, + you can do this:</P> <PRE> BEGIN; LOCK TABLE old_table; @@ -1023,13 +1026,13 @@ <PRE> SELECT * FROM tab - WHERE LOWER(col) = 'abc'; + WHERE lower(col) = 'abc'; </PRE> This will not use an standard index. However, if you create a functional index, it will be used: <PRE> - CREATE INDEX tabindex ON tab (LOWER(col)); + CREATE INDEX tabindex ON tab (lower(col)); </PRE> <H4><A name="4.13">4.13</A>) In a query, how do I detect if a field @@ -1118,7 +1121,7 @@ BYTEA bytea variable-length byte array (null-byte safe) and your <SMALL>SERIAL</SMALL> column, respectively. <P>Alternatively, you could retrieve the assigned - <SMALL>SERIAL</SMALL> value with the <I>currval</I>() function + <SMALL>SERIAL</SMALL> value with the <I>currval()</I> function <I>after</I> it was inserted by default, e.g.,</P> <PRE> execute("INSERT INTO person (name) VALUES ('Blaise Pascal')"); @@ -1135,7 +1138,7 @@ BYTEA bytea variable-length byte array (null-byte safe) <H4><A name="4.15.3">4.15.3</A>) Don't <I>currval()</I> and <I>nextval()</I> lead to a race condition with other users?</H4> - <P>No. <i>currval</i>() returns the current value assigned by your + <P>No. <I>currval()</I> returns the current value assigned by your backend, not by all users.</P> <H4><A name="4.15.4">4.15.4</A>) Why aren't my sequence numbers |