</CENTER>
<A href="#2.1">2.1</A>) Are there <SMALL>ODBC</SMALL> drivers for
PostgreSQL?<BR>
- <A href="#2.2">2.2</A>) What tools are available for use PostgreSQL
- with Web pages?<BR>
+ <A href="#2.2">2.2</A>) What tools are available for use
+ PostgreSQL with Web pages?<BR>
<A href="#2.3">2.3</A>) Does PostgreSQL have a graphical user
interface? A report generator? An embedded query language
interface?<BR>
database?<BR>
<A href="#4.7">4.7</A>) How much database disk space is required
to store data from a typical text file?<BR>
- <A href="#4.8">4.8</A>) How do I find out what tables or
- indexes are defined in the database?<BR>
+ <A href="#4.8">4.8</A>) How do I find out what tables or indexes
+ are defined in the database?<BR>
<A href="#4.9">4.9</A>) My queries are slow or don't make use of
the indexes. Why?<BR>
<A href="#4.10">4.10</A>) How do I see how the query optimizer is
evaluating my query?<BR>
<A href="#4.11">4.11</A>) What is an R-tree index?<BR>
<A href="#4.12">4.12</A>) What is the Genetic Query Optimizer?<BR>
- <A href="#4.13">4.13</A>) How do I perform regular expression searches
- and case-insensitive regular expression searches?<BR>
+ <A href="#4.13">4.13</A>) How do I perform regular expression
+ searches and case-insensitive regular expression searches?<BR>
<A href="#4.14">4.14</A>) In a query, how do I detect if a field
is <SMALL>NULL</SMALL>?<BR>
<A href="#4.15">4.15</A>) What is the difference between the
<P>PostgreSQL Data Base Management System</P>
- <P>Portions copyright (c) 1996-2001, PostgreSQL Global Development Group Portions
- Copyright (c) 1994-6 Regents of the University of California</P>
+ <P>Portions copyright (c) 1996-2001, PostgreSQL Global Development
+ Group Portions Copyright (c) 1994-6 Regents of the University of
+ California</P>
<P>Permission to use, copy, modify, and distribute this software
and its documentation for any purpose, without fee, and without a
"mailto:postgres95@openlink.co.uk">postgres95@openlink.co.uk</A>.</P>
<P>See also the <A href=
- "http://www.PostgreSQL.org/users-lounge/docs/programmer/odbc.htm">ODBC chapter
- of the Programmer's Guide</A>.</P>
+ "http://www.PostgreSQL.org/users-lounge/docs/programmer/odbc.htm">ODBC
+ chapter of the Programmer's Guide</A>.</P>
<H4><A name="2.2">2.2</A>) What tools are available for using
PostgreSQL with Web pages?</H4>
Maximum number of indexes on a table? unlimited
</PRE>
Of course, these are not actually unlimited, but limited to
- available disk space and memory/swap space. Performance may
- suffer when these values get unusually large.
+ available disk space and memory/swap space. Performance may suffer
+ when these values get unusually large.
<P>The maximum table size of 16TB does not require large file
- support from the operating system. Large tables are stored
- as multiple 1GB files.
-
+ support from the operating system. Large tables are stored as
+ multiple 1GB files.</P>
+
<P>The maximum table size and maximum number of columns can be
increased by a factor of four if the default block size is
- increased to 32k.
+ increased to 32k.</P>
<H4><A name="4.7">4.7</A>) How much database disk space is required
to store data from a typical text file?<BR>
<P>Indexes do not require as much overhead, but do contain the data
that is being indexed, so they can be large also.</P>
- <H4><A name="4.8">4.8</A>) How do I find out what tables or
- indexes are defined in the database?</H4>
+ <H4><A name="4.8">4.8</A>) How do I find out what tables or indexes
+ are defined in the database?</H4>
<P><I>psql</I> has a variety of backslash commands to show such
information. Use \? to see them.</P>
<P>The <I>~</I> operator does regular expression matching, and
<I>~*</I> does case-insensitive regular expression matching. The
- case-insensitive variant of <SMALL>LIKE</SMALL>
- is called <SMALL>ILIKE</SMALL>.</P>
+ case-insensitive variant of <SMALL>LIKE</SMALL> is called
+ <SMALL>ILIKE</SMALL>.</P>
<H4><A name="4.14">4.14</A>) In a query, how do I detect if a field
is <SMALL>NULL</SMALL>?</H4>
SELECT *
FROM t1 LEFT OUTER JOIN t2 ON (t1.col = t2.col);
</PRE>
-or
+ or
<PRE>
SELECT *
FROM t1 LEFT OUTER JOIN t2 USING (col);
</PRE>
- These identical queries join t1.col to t2.col, and also return any
- unjoined rows in t1 (those with no match in t2). A
+
+ <P>These identical queries join t1.col to t2.col, and also return
+ any unjoined rows in t1 (those with no match in t2). A
<SMALL>RIGHT</SMALL> join would add unjoined rows of t2. A
<SMALL>FULL</SMALL> join would return the matched rows plus all
unjoined rows from t1 and t2. The word <SMALL>OUTER</SMALL> is
joining <I>tab1</I> and <I>tab2,</I> the following query does an
<I>outer</I> join of the two tables:<BR>
<BR>
-
+ </P>
<PRE>
SELECT tab1.col1, tab2.col2
FROM tab1, tab2
compiler compute the dependencies automatically.</P>
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+