More minor updates and copy-editing.

doc/src/sgml/ecpg.sgml

@@ -1,5 +1,5 @@
 <!--
-$PostgreSQL: pgsql/doc/src/sgml/ecpg.sgml,v 1.59 2003/12/26 20:00:00 meskes Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ecpg.sgml,v 1.60 2004/12/28 22:47:15 tgl Exp $
 -->
 
 <chapter id="ecpg">
@@ -19,7 +19,7 @@ $PostgreSQL: pgsql/doc/src/sgml/ecpg.sgml,v 1.59 2003/12/26 20:00:00 meskes Exp
  </para>
 
  <para>
-  Admittedly, this documentation is quite incomplete.  But since this
+  This documentation is quite incomplete.  But since this
   interface is standardized, additional information can be found in
   many resources about SQL.
  </para>
@@ -31,9 +31,9 @@ $PostgreSQL: pgsql/doc/src/sgml/ecpg.sgml,v 1.59 2003/12/26 20:00:00 meskes Exp
    An embedded SQL program consists of code written in an ordinary
    programming language, in this case C, mixed with SQL commands in
    specially marked sections.  To build the program, the source code
-   is first passed to the embedded SQL preprocessor, which converts it
+   is first passed through the embedded SQL preprocessor, which converts it
    to an ordinary C program, and afterwards it can be processed by a C
-   compilation tool chain.
+   compiler.
   </para>
 
   <para>
@@ -53,7 +53,7 @@ $PostgreSQL: pgsql/doc/src/sgml/ecpg.sgml,v 1.59 2003/12/26 20:00:00 meskes Exp
   </para>
 
   <para>
-   As indicated, programs written for the embedded
+   As already stated, programs written for the embedded
    <acronym>SQL</acronym> interface are normal C programs with special
    code inserted to perform database-related actions.  This special
    code always has the form
@@ -61,8 +61,8 @@ $PostgreSQL: pgsql/doc/src/sgml/ecpg.sgml,v 1.59 2003/12/26 20:00:00 meskes Exp
 EXEC SQL ...;
 </programlisting>
    These statements syntactically take the place of a C statement.
-   Depending on the particular statement, they may appear in the
+   Depending on the particular statement, they may appear at the
-   global context or within a function.  Embedded
+   global level or within a function.  Embedded
    <acronym>SQL</acronym> statements follow the case-sensitivity rules
    of normal <acronym>SQL</acronym> code, and not those of C.
   </para>
@@ -326,9 +326,9 @@ EXEC SQL COMMIT;
   <para>
    In the default mode, statements are committed only when
    <command>EXEC SQL COMMIT</command> is issued. The embedded SQL
-   interface also supports autocommit of transactions (as known from
+   interface also supports autocommit of transactions (similar to
-   other interfaces) via the <option>-t</option> command-line option
+   <application>libpq</> behavior) via the <option>-t</option> command-line
-   to <command>ecpg</command> (see below) or via the <literal>EXEC SQL
+   option to <command>ecpg</command> (see below) or via the <literal>EXEC SQL
    SET AUTOCOMMIT TO ON</literal> statement. In autocommit mode, each
    command is automatically committed unless it is inside an explicit
    transaction block. This mode can be explicitly turned off using
@@ -448,7 +448,7 @@ char  foo[16], bar[16];
    <para>
     The declarations are also echoed to the output file as a normal C
     variables, so there's no need to declare them again.  Variables
-    that are not intended to be used with SQL commands can be declared
+    that are not intended to be used in SQL commands can be declared
     normally outside these special sections.
    </para>
 
@@ -553,7 +553,7 @@ do {
     second host variable specification to each host variable that
     contains data.  This second host variable is called the
     <firstterm>indicator</firstterm> and contains a flag that tells
-    whether the datums is null, in which case the value of the real
+    whether the datum is null, in which case the value of the real
     host variable is ignored.  Here is an example that handles the
     retrieval of null values correctly:
 <programlisting>
@@ -1043,7 +1043,7 @@ static void set_error_handler(void)
    <title>sqlca</title>
 
    <para>
-    For a more powerful error handling, the embedded SQL interface
+    For more powerful error handling, the embedded SQL interface
     provides a global variable with the name <varname>sqlca</varname>
     that has the following structure:
 <programlisting>
@@ -1064,7 +1064,7 @@ struct
 } sqlca;
 </programlisting>
     (In a multithreaded program, every thread automatically gets its
-    own copy of <varname>sqlca</varname>.  This works similar to the
+    own copy of <varname>sqlca</varname>.  This works similarly to the
     handling of the standard C global variable
     <varname>errno</varname>.)
    </para>
@@ -1132,7 +1132,7 @@ struct
    <para>
     The structure <varname>sqlca</varname> is not defined in the SQL
     standard, but is implemented in several other SQL database
-    systems.  The definitions are similar in the core, but if you want
+    systems.  The definitions are similar at the core, but if you want
     to write portable applications, then you should investigate the
     different implementations carefully.
    </para>
@@ -1539,7 +1539,7 @@ ecpg prog1.pgc
 <programlisting>
 cc -c prog1.c
 </programlisting>
-   The generated C source files include headers files from the
+   The generated C source files include header files from the
    <productname>PostgreSQL</> installation, so if you installed
    <productname>PostgreSQL</> in a location that is not searched by
    default, you have to add an option such as
@@ -1575,9 +1575,9 @@ ECPG = ecpg
   </para>
 
   <para>
-   <application>ecpg</application> is thread-safe if it is compiled using
+   The <application>ecpg</application> library is thread-safe if it is built
-   the <option>--enable-thread-safety</> <filename>configure</filename>
+   using the <option>--enable-thread-safety</> command-line option to
-   command-line option.  (You might need to use other threading
+   <filename>configure</filename>.  (You might need to use other threading
    command-line options to compile your client code.)
   </para>
  </sect1>
@@ -1621,7 +1621,7 @@ ECPG = ecpg
   <title>Internals</title>
 
   <para>
-   This section explain how <application>ECPG</application> works
+   This section explains how <application>ECPG</application> works
    internally. This information can occasionally be useful to help
    users understand how to use <application>ECPG</application>.
   </para>

doc/src/sgml/external-projects.sgml

@@ -1,5 +1,5 @@
 <!--
-$PostgreSQL: pgsql/doc/src/sgml/external-projects.sgml,v 1.5 2004/12/13 18:05:08 petere Exp $
+$PostgreSQL: pgsql/doc/src/sgml/external-projects.sgml,v 1.6 2004/12/28 22:47:15 tgl Exp $
 -->
 
  <chapter id="external-projects">
@@ -9,15 +9,28 @@ $PostgreSQL: pgsql/doc/src/sgml/external-projects.sgml,v 1.5 2004/12/13 18:05:08
    <productname>PostgreSQL</productname> is a complex software project,
    and managing it is difficult. We have found that many
    enhancements to <productname>PostgreSQL</productname> can be more
-   efficiently developed independently of the main project. They can
+   efficiently developed separately from the core project. Separate
-   have their own developer teams, email lists, their own bug tracking,
+   projects can
-   and their own release schedule. While their independence makes
+   have their own developer teams, email lists, bug tracking,
-   development easier, it makes user's jobs harder. They have to hunt
+   and release schedules. While their independence makes
+   development easier, it makes users' jobs harder. They have to hunt
    around looking for database enhancements to meet their needs.
-   This section outlines some of the more popular externally
+   This section describes some of the more popular externally
    developed enhancements and guides you on how to find them.
   </para>
 
+  <para>
+   Many <productname>PostgreSQL</productname>-related projects are
+   hosted at either
+   <productname>GBorg</> at <ulink url="http://gborg.postgresql.org">
+   http://gborg.postgresql.org</ulink> or
+   <productname>pgFoundry</> at <ulink
+   url="http://pgfoundry.org">http://pgfoundry.org</ulink>.
+   There are other
+   <productname>PostgreSQL</productname>-related projects that are hosted
+   elsewhere, but you will have to do an Internet search to find them.
+  </para>
+
  <sect1 id="interfaces">
   <title>Externally Developed Interfaces</title>
 
@@ -36,11 +49,7 @@ $PostgreSQL: pgsql/doc/src/sgml/external-projects.sgml,v 1.5 2004/12/13 18:05:08
   </para>
 
   <para>
-   To use other interfaces, you have to do some searching. For example,
+   Some of the more popular interfaces are:
-   <productname>GBorg</> at <ulink url="http://gborg.postgresql.org">
-   http://gborg.postgresql.org</ulink> has over thirty interfaces listed
-   in its <literal>Drivers/Interfaces</> section. Some of the more
-   popular interfaces are:
 
    <variablelist>
     <varlistentry>
@@ -53,6 +62,15 @@ $PostgreSQL: pgsql/doc/src/sgml/external-projects.sgml,v 1.5 2004/12/13 18:05:08
      </listitem>
     </varlistentry>
 
+    <varlistentry>
+     <term>pgjdbc</term>
+     <listitem>
+      <para>
+       A <application>JDBC</> interface.
+      </para>
+     </listitem>
+    </varlistentry>
+
     <varlistentry>
      <term>Npgsql</term>
      <listitem>
@@ -64,19 +82,19 @@ $PostgreSQL: pgsql/doc/src/sgml/external-projects.sgml,v 1.5 2004/12/13 18:05:08
     </varlistentry>
 
     <varlistentry>
-     <term>libpq++</term>
+     <term>libpqxx</term>
      <listitem>
       <para>
-       An older <application>C++</> interface.
+       A newer <application>C++</> interface.
       </para>
      </listitem>
     </varlistentry>
 
     <varlistentry>
-     <term>libpqxx</term>
+     <term>libpq++</term>
      <listitem>
       <para>
-       A newer <application>C++</> interface.
+       An older <application>C++</> interface.
       </para>
      </listitem>
     </varlistentry>
@@ -101,11 +119,20 @@ $PostgreSQL: pgsql/doc/src/sgml/external-projects.sgml,v 1.5 2004/12/13 18:05:08
      </listitem>
     </varlistentry>
 
+    <varlistentry>
+     <term>pgtclng</term>
+     <listitem>
+      <para>
+       A newer version of the <application>Tcl</> interface.
+      </para>
+     </listitem>
+    </varlistentry>
+
     <varlistentry>
      <term>pgtcl</term>
      <listitem>
       <para>
-       The original version of the <application>TCL</> interface.
+       The original version of the <application>Tcl</> interface.
       </para>
      </listitem>
     </varlistentry>
@@ -119,35 +146,9 @@ $PostgreSQL: pgsql/doc/src/sgml/external-projects.sgml,v 1.5 2004/12/13 18:05:08
      </listitem>
     </varlistentry>
 
-    <varlistentry>
-     <term>pgjdbc</term>
-     <listitem>
-      <para>
-       A <application>JDBC</> interface.
-      </para>
-     </listitem>
-    </varlistentry>
-
-    <varlistentry>
-     <term>pgtclng</term>
-     <listitem>
-      <para>
-       A newer version of the <application>TCL</> interface.
-      </para>
-     </listitem>
-    </varlistentry>
-
    </variablelist>
    </para>
 
-  <para>
-   That section also contains several server-side languages that are
-   separate projects. <application>pgFoundry</> at <ulink
-   url="http://pgfoundry.org">http://pgfoundry.org</ulink> contains
-   even more projects. Other projects are not even hosted on these
-   servers and you will have to do an Internet search to find them.
-  </para>
-
  </sect1>
  
  <sect1 id="extensions">
@@ -169,7 +170,7 @@ $PostgreSQL: pgsql/doc/src/sgml/external-projects.sgml,v 1.5 2004/12/13 18:05:08
    like <application>PostGIS</>. Even <application>PostgreSQL</>
    replication solutions are developed externally. For example,
    <application>Slony-I</> is a popular master/slave replication solution
-   that is developed independently from the main projects.
+   that is developed independently from the core project.
   </para>
 
   <para>

doc/src/sgml/information_schema.sgml

@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/information_schema.sgml,v 1.19 2004/11/27 21:27:06 petere Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/information_schema.sgml,v 1.20 2004/12/28 22:47:15 tgl Exp $ -->
 
 <chapter id="information-schema">
  <title>The Information Schema</title>
@@ -30,7 +30,7 @@
    exists in all databases.  The owner of this schema is the initial
    database user in the cluster, and that user naturally has all the
    privileges on this schema, including the ability to drop it (but
-   the space savings achieved by this are minuscule).
+   the space savings achieved by that are minuscule).
   </para>
 
   <para>
@@ -1003,7 +1003,7 @@
    function (as parameter or return type) and stores some information
    about how the data type is used in that instance (for example, the
    declared maximum length, if applicable).  Each data type
-   descriptors is assigned an arbitrary identifier that is unique
+   descriptor is assigned an arbitrary identifier that is unique
    among the data type descriptor identifiers assigned for one object
    (table, domain, function).  This view is probably not useful for
    applications, but it is used to define some other views in the
@@ -1735,7 +1735,7 @@ ORDER BY c.ordinal_position;
    in the current database that are restricted by some unique, primary
    key, or foreign key constraint.  Check constraints are not included
    in this view.  Only those columns are shown that are contained in a
-   table owned the current user.
+   table owned by the current user.
   </para>
 
   <table>
@@ -3320,7 +3320,7 @@ ORDER BY c.ordinal_position;
 
   <para>
    The table <literal>sql_packages</literal> contains information
-   about which features packages defined in the SQL standard are
+   about which feature packages defined in the SQL standard are
    supported by <productname>PostgreSQL</productname>.  Refer to <xref
    linkend="features"> for background information on feature packages.
   </para>
@@ -3888,7 +3888,7 @@ ORDER BY c.ordinal_position;
    incompatibilities with the SQL standard that affect the
    representation in the information schema.  First, trigger names are
    local to the table in <productname>PostgreSQL</productname>, rather
-   than independent schema objects.  Therefore there may be duplicate
+   than being independent schema objects.  Therefore there may be duplicate
    trigger names defined in one schema, as long as they belong to
    different tables.  (<literal>trigger_catalog</literal> and
    <literal>trigger_schema</literal> are really the values pertaining

doc/src/sgml/libpq.sgml

@@ -1,5 +1,5 @@
 <!--
-$PostgreSQL: pgsql/doc/src/sgml/libpq.sgml,v 1.172 2004/12/20 18:15:05 tgl Exp $
+$PostgreSQL: pgsql/doc/src/sgml/libpq.sgml,v 1.173 2004/12/28 22:47:15 tgl Exp $
 -->
 
  <chapter id="libpq">
@@ -19,11 +19,19 @@ $PostgreSQL: pgsql/doc/src/sgml/libpq.sgml,v 1.172 2004/12/20 18:15:05 tgl Exp $
    <application>libpq</> is a set of library functions that allow
    client programs to pass queries to the <productname>PostgreSQL</>
    backend server and to receive the results of these queries.
+  </para>
+
+  <para>
    <application>libpq</> is also the underlying engine for several
    other <productname>PostgreSQL</> application interfaces, including
-   those written for C++, TCL, Perl, Python and <application>ECPG</>.
+   those written for C++, Perl, Python, Tcl and <application>ECPG</>.
    So some aspects of <application>libpq</>'s behavior will be
-   important to you if you use one of those packages.
+   important to you if you use one of those packages.  In particular,
+   <xref linkend="libpq-envars">,
+   <xref linkend="libpq-pgpass"> and
+   <xref linkend="libpq-ssl">
+   describe behavior that is visible to the user of any application
+   that uses <application>libpq</>.
   </para>
 
   <para>
@@ -49,7 +57,7 @@ $PostgreSQL: pgsql/doc/src/sgml/libpq.sgml,v 1.172 2004/12/20 18:15:05 tgl Exp $
    application program can have several backend connections open at
    one time.  (One reason to do that is to access more than one
    database.)  Each connection is represented by a
-   <structname>PGconn</><indexterm><primary>PGconn</></> object which
+   <structname>PGconn</><indexterm><primary>PGconn</></> object, which
    is obtained from the function <function>PQconnectdb</> or
    <function>PQsetdbLogin</>.  Note that these functions will always
    return a non-null object pointer, unless perhaps there is too
@@ -82,12 +90,12 @@ PGconn *PQconnectdb(const char *conninfo);
    can be empty to use all default parameters, or it can contain one or more
    parameter settings separated by whitespace.
    Each parameter setting is in the form <literal>keyword = value</literal>.
-   (To write an empty value or a value containing
+   Spaces around the 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 <literal>\\</literal>.)
+   backslash, i.e., <literal>\'</literal> and <literal>\\</literal>.
-   Spaces around the equal sign are optional.
    </para>
 
    <para>
@@ -172,6 +180,8 @@ PGconn *PQconnectdb(const char *conninfo);
      <listitem>
      <para>
       <productname>PostgreSQL</productname> user name to connect as.
+      Defaults to be the same as the operating system name of the user
+      running the application.
      </para>
      </listitem>
     </varlistentry>
@@ -235,7 +245,7 @@ PGconn *PQconnectdb(const char *conninfo);
        If <productname>PostgreSQL</> is compiled without SSL support,
        using option <literal>require</> will cause an error, while
        options <literal>allow</> and <literal>prefer</> will be
-       tolerated but <application>libpq</> will be unable to negotiate
+       accepted but <application>libpq</> will not in fact attempt
        an <acronym>SSL</>
        connection.<indexterm><primary>SSL</><secondary
        sortas="libpq">with libpq</></indexterm>
@@ -273,8 +283,8 @@ PGconn *PQconnectdb(const char *conninfo);
       name in <filename>pg_service.conf</filename> that holds additional connection parameters.
       This allows applications to specify only a service name so connection parameters 
       can be centrally maintained.  See 
-      <filename><replaceable>PREFIX</>/share/pg_service.conf.sample</> for
+      <filename>share/pg_service.conf.sample</> in the installation
-      information on how to set up the file.
+      directory for information on how to set up the file.
      </para>
      </listitem>
     </varlistentry>
@@ -283,7 +293,7 @@ PGconn *PQconnectdb(const char *conninfo);
    If  any  parameter is unspecified, then the corresponding
    environment variable (see <xref linkend="libpq-envars">)
    is checked. If the  environment  variable is not set either,
-   then built-in defaults are used.
+   then the indicated built-in defaults are used.
    </para>
   </listitem>
  </varlistentry>
@@ -489,7 +499,7 @@ PostgresPollingStatusType PQconnectPoll(PGconn *conn);
     </variablelist>
 
     Note that, although these constants will remain (in order to maintain
-    compatibility), an application should never rely upon these appearing in a
+    compatibility), an application should never rely upon these occurring in a
     particular order, or at all, or on the status always being one of these
     documented values. An application might do something like this:
 <programlisting>
@@ -877,7 +887,8 @@ Pre-3.0-protocol servers do not report parameter settings, but
 <application>libpq</> includes logic to obtain values for
 <literal>server_version</> and <literal>client_encoding</> anyway.
 Applications are encouraged to use <function>PQparameterStatus</>
-rather than ad-hoc code to determine these values.  (Beware however
+rather than <foreignphrase>ad hoc</> code to determine these values.
+(Beware however
 that on a pre-3.0 connection, changing <literal>client_encoding</> via
 <command>SET</> after connection startup will not be reflected by
 <function>PQparameterStatus</>.)  For <literal>server_version</>,
@@ -905,8 +916,8 @@ Applications may wish to use this to determine whether certain features
 are supported.
 Currently, the possible values are 2 (2.0 protocol), 3 (3.0 protocol),
 or zero (connection bad).  This will not change after connection
-startup is complete, but it could theoretically change during a reset.
+startup is complete, but it could theoretically change during a connection
-The 3.0 protocol will normally be used when communicating with
+reset.  The 3.0 protocol will normally be used when communicating with
 <productname>PostgreSQL</> 7.4 or later servers; pre-7.4 servers support
 only protocol 2.0.  (Protocol 1.0 is obsolete and not supported by <application>libpq</application>.)
 </para>
@@ -950,7 +961,9 @@ char *PQerrorMessage(const PGconn *conn);
        <function>PQerrorMessage</function> result will
        include a trailing newline. The caller should not free the result 
        directly. It will be freed when the associated <structname>PGconn</> 
-       handle is passed to <function>PQfinish</function>.
+       handle is passed to <function>PQfinish</function>.  The result string
+       should not be expected to remain the same across operations on the
+       <literal>PGconn</> structure.
       </para>
      </listitem>
     </varlistentry>
@@ -1014,7 +1027,7 @@ SSL *PQgetssl(const PGconn *conn);
       </para>
       <para>
        You must define <symbol>USE_SSL</symbol> in order to get the
-       prototype for this function. Doing this will also 
+       correct prototype for this function. Doing this will also 
        automatically include <filename>ssl.h</filename> from <productname>OpenSSL</productname>.
       </para>
      </listitem>
@@ -1768,7 +1781,8 @@ exactly which table is referenced.
 <para>
  Returns the column number (within its table) of the column making up
  the specified query result column.
- Result column numbers start at 0.
+ Query-result column numbers start at 0, but table columns have nonzero
+ numbers.
 <synopsis>
 int PQftablecol(const PGresult *res,
                 int column_number);
@@ -2678,7 +2692,7 @@ server, using the functions described in this section.
 <listitem>
 <para>
           Creates a data structure containing the information needed to cancel
-	  a command issued through a particular database connection.
+          a command issued through a particular database connection.
 <synopsis>
 PGcancel *PQgetCancel(PGconn *conn);
 </synopsis>
@@ -3614,8 +3628,9 @@ information into simple client applications, for example.
 </indexterm>
 <envar>PGHOST</envar> sets the database server name.
 If this begins with a slash, it specifies Unix-domain communication
-rather than TCP/IP communication; the value is the name of the
+rather than TCP/IP communication; the value is then the name of the
-directory in which the socket file is stored (default <filename>/tmp</filename>).
+directory in which the socket file is stored (in a default installation
+setup this would be <filename>/tmp</filename>).
 </para>
 </listitem>
 <listitem>
@@ -3624,8 +3639,8 @@ directory in which the socket file is stored (default <filename>/tmp</filename>)
  <primary><envar>PGHOSTADDR</envar></primary>
 </indexterm>
 <envar>PGHOSTADDR</envar> specifies the numeric IP address of the database
-server.  This can be set instead of <envar>PGHOST</envar> to avoid DNS
+server.  This can be set instead of or in addition to <envar>PGHOST</envar>
-lookup overhead. See the documentation of
+to avoid DNS lookup overhead. See the documentation of
 these parameters, under <function>PQconnectdb</function> above, for details
 on their interaction.
 </para>
@@ -3666,7 +3681,7 @@ sets the user name used to connect to the database.
 <envar>PGPASSWORD</envar>
 sets the password used if the server demands password
 authentication.  This environment variable is deprecated for security
-reasons; consider migrating to use the <filename>$HOME/.pgpass</>
+reasons; instead consider using the <filename>$HOME/.pgpass</>
 file (see <xref linkend="libpq-pgpass">).
 </para>
 </listitem>
@@ -3718,9 +3733,9 @@ trying an <acronym>SSL</> connection; <literal>prefer</>
 connection, then if that fails, trying a regular non-<acronym>SSL</>
 connection; <literal>require</> will try only an <acronym>SSL</>
 connection. If <productname>PostgreSQL</> is compiled without SSL support,
-using option <literal>require</> will cause an error, and options
+using option <literal>require</> will cause an error, while options
-<literal>allow</> and <literal>prefer</> will be tolerated but
+<literal>allow</> and <literal>prefer</> will be accepted but
-<application>libpq</> will be unable to negotiate an <acronym>SSL</>
+<application>libpq</> will not in fact attempt an <acronym>SSL</>
 connection.
 </para>
 </listitem>
@@ -3758,7 +3773,9 @@ It is not recommended to set the timeout to less than 2 seconds.
 <para>
 The following environment variables can be used to specify default
 behavior for each <productname>PostgreSQL</productname> session.
-(See also the <command>ALTER USER</> and <command>ALTER DATABASE</>
+(See also the
+<xref linkend="sql-alteruser" endterm="sql-alteruser-title"> and
+<xref linkend="sql-alterdatabase" endterm="sql-alterdatabase-title">
 commands for ways to set default behavior on a per-user or per-database
 basis.)
 
@@ -3803,6 +3820,18 @@ sets the default mode for the genetic query optimizer.
 (Equivalent to <literal>SET geqo TO ...</literal>.)
 </para>
 </listitem>
+</itemizedlist>
+
+Refer to the <acronym>SQL</acronym> command 
+<xref linkend="sql-set" endterm="sql-set-title">
+for information on correct values for these environment variables.
+</para>
+
+<para>
+The following environment variables determine internal behavior of
+<application>libpq</application>; they override compiled-in defaults.
+
+<itemizedlist>
 <listitem>
 <para>
 <indexterm>
@@ -3818,13 +3847,11 @@ sets the directory containing the <filename>pg_service.conf</> file.
  <primary><envar>PGLOCALEDIR</envar></primary>
 </indexterm>
 <envar>PGLOCALEDIR</envar>
-sets the directory containing the <literal>locale</> files.
+sets the directory containing the <literal>locale</> files for message
+internationalization.
 </para>
 </listitem>
 </itemizedlist>
-
-Refer to the <acronym>SQL</acronym> command <command>SET</command>
-for information on correct values for these environment variables.
 </para>
 
 </sect1>
@@ -3910,7 +3937,7 @@ If the permissions are less strict than this, the file will be ignored.
 <para>
 <application>libpq</application> is reentrant and thread-safe if the
 <filename>configure</filename> command-line option
-<literal>--enable-thread-safety</> has been used when the
+<literal>--enable-thread-safety</> was used when the
 <productname>PostgreSQL</productname> distribution was built.  In
 addition, you might need to use additional compiler command-line
 options when you compile your application code.  Refer to your
@@ -3974,7 +4001,8 @@ your library might not match the library used to build the binaries.
   </indexterm>
 
   <para>
-   To build (i.e., compile and link) your <application>libpq</application> programs you need to
+   To build (i.e., compile and link) a program using
+   <application>libpq</application> you need to 
    do all of the following things:
 
    <itemizedlist>

doc/src/sgml/lobj.sgml

@@ -1,5 +1,5 @@
 <!--
-$PostgreSQL: pgsql/doc/src/sgml/lobj.sgml,v 1.33 2003/11/29 19:51:37 pgsql Exp $
+$PostgreSQL: pgsql/doc/src/sgml/lobj.sgml,v 1.34 2004/12/28 22:47:15 tgl Exp $
 -->
 
  <chapter id="largeObjects">
@@ -9,15 +9,11 @@ $PostgreSQL: pgsql/doc/src/sgml/lobj.sgml,v 1.33 2003/11/29 19:51:37 pgsql Exp $
   <indexterm><primary>BLOB</><see>large object</></>
 
    <para>
-    In <productname>PostgreSQL</productname> releases prior to 7.1,
+    <productname>PostgreSQL</productname> has a <firstterm>large object</>
-    the size of any row in the database could not exceed the size of a
+    facility, which provides stream-style access to user data that is stored
-    data page.  Since the size of a data page is 8192 bytes (the
+    in a special large-object structure.  Streaming access is useful
-    default, which can be raised up to 32768), the upper limit on the
+    when working with data values that are too large to manipulate
-    size of a data value was relatively low. To support the storage of
+    conveniently as a whole.
-    larger atomic values, <productname>PostgreSQL</productname>
-    provided and continues to provide a large object interface.  This
-    interface provides file-oriented access to user data that is stored in
-    a special large-object structure.
    </para>
 
    <para>
@@ -59,10 +55,13 @@ $PostgreSQL: pgsql/doc/src/sgml/lobj.sgml,v 1.33 2003/11/29 19:51:37 pgsql Exp $
     <indexterm><primary>sliced bread</><see>TOAST</></indexterm>
     <productname>PostgreSQL 7.1</productname> introduced a mechanism
     (nicknamed <quote><acronym>TOAST</acronym></quote>) that allows
-    data rows to be much larger than individual data pages.  This
+    data values to be much larger than single pages.  This
-    makes the large object interface partially obsolete.  One
+    makes the large object facility partially obsolete.  One
-    remaining advantage of the large object interface is that it allows values up
+    remaining advantage of the large object facility is that it allows values
-    to 2 GB in size, whereas <acronym>TOAST</acronym> can only handle 1 GB.
+    up to 2 GB in size, whereas <acronym>TOAST</acronym>ed fields can be at
+    most 1 GB.  Also, large objects can be manipulated piece-by-piece much more
+    easily than ordinary data fields, so the practical limits are considerably
+    different.
    </para>
 
   </sect1>
@@ -117,7 +116,7 @@ Oid lo_creat(PGconn *conn, int mode);
      creates a new large  object.  
      <replaceable class="parameter">mode</replaceable>  is  a  bit mask
      describing  several  different  attributes  of  the new
-     object.  The symbolic constants listed here are defined
+     object.  The symbolic constants used here are defined
      in the header file <filename>libpq/libpq-fs.h</filename>.
      The access type (read, write, or both) is controlled by
      or'ing together the bits <symbol>INV_READ</symbol>  and
@@ -149,6 +148,9 @@ Oid lo_import(PGconn *conn, const char *filename);
      specifies the operating system name of
      the file to be imported as a large object.
      The return value is the OID that was assigned to the new large object.
+     Note that the file is read by the client interface library, not by
+     the server; so it must exist in the client filesystem and be readable
+     by the client application.
     </para>
    </sect2>
 
@@ -164,7 +166,9 @@ int lo_export(PGconn *conn, Oid lobjId, const char *filename);
      <indexterm><primary>lo_export</></>
      The <parameter>lobjId</parameter> argument specifies  the  OID  of  the  large
      object  to  export  and the <parameter>filename</parameter> argument specifies
-     the operating system name name of the file.
+     the operating system name of the file.
+     Note that the file is written by the client interface library, not by
+     the server.
     </para>
    </sect2>
 
@@ -200,7 +204,7 @@ int lo_write(PGconn *conn, int fd, const char *buf, size_t len);
 </synopsis>
      <indexterm><primary>lo_write</></> writes
      <parameter>len</parameter> bytes from <parameter>buf</parameter>
-     to large object <parameter>fd</>.  The <parameter>fd</parameter>
+     to large object descriptor <parameter>fd</>.  The <parameter>fd</parameter>
      argument must have been returned by a previous
      <function>lo_open</function>.  The number of bytes actually
      written is returned.  In the event of an error, the return value
@@ -217,7 +221,7 @@ int lo_write(PGconn *conn, int fd, const char *buf, size_t len);
 int lo_read(PGconn *conn, int fd, char *buf, size_t len);
 </synopsis>
      <indexterm><primary>lo_read</></> reads
-     <parameter>len</parameter> bytes from large object
+     <parameter>len</parameter> bytes from large object descriptor
      <parameter>fd</parameter> into <parameter>buf</parameter>. The
      <parameter>fd</parameter> argument must have been returned by a
      previous <function>lo_open</function>.  The number of bytes
@@ -227,16 +231,16 @@ int lo_read(PGconn *conn, int fd, char *buf, size_t len);
 </sect2>
 
 <sect2>
-<title>Seeking on a Large Object</title>
+<title>Seeking in a Large Object</title>
 
 <para>
-     To change the current read or write location on a large
+     To change the current read or write location associated with a
-     object, call
+     large object descriptor, call
 <synopsis>
 int lo_lseek(PGconn *conn, int fd, int offset, int whence);
 </synopsis>
      <indexterm><primary>lo_lseek</></> This function moves the
-     current location pointer for the large object described by
+     current location pointer for the large object descriptor identified by
      <parameter>fd</> to the new location specified by
      <parameter>offset</>.  The valid values for <parameter>whence</>
      are <symbol>SEEK_SET</> (seek from object start),
@@ -250,7 +254,7 @@ int lo_lseek(PGconn *conn, int fd, int offset, int whence);
 <title>Obtaining the Seek Position of a Large Object</title>
 
 <para>
-     To obtain the current read or write location of a large object,
+     To obtain the current read or write location of a large object descriptor,
      call
 <synopsis>
 int lo_tell(PGconn *conn, int fd);
@@ -264,7 +268,7 @@ int lo_tell(PGconn *conn, int fd);
 <title>Closing a Large Object Descriptor</title>
 
 <para>
-     A large object may be closed by calling
+     A large object descriptor may be closed by calling
 <synopsis>
 int lo_close(PGconn *conn, int fd);
 </synopsis>