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Overview
Comment:More documentation updates (CVS 295)
Downloads: Tarball | ZIP archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA1: f65df59e554c281ad1efa830f13f87488eb16845
User & Date: drh 2001-10-31 15:44:47.000
Context
2001-11-01
13:52
Comment changes only. (CVS 296) (check-in: b2cb118fb7 user: drh tags: trunk)
2001-10-31
15:44
More documentation updates (CVS 295) (check-in: f65df59e55 user: drh tags: trunk)
2001-10-25
20:37
Make lemon 64-bit clean (CVS 294) (check-in: 475e2fedda user: drh tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to www/c_interface.tcl. 
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#
# Run this Tcl script to generate the sqlite.html file.
#
set rcsid {$Id: c_interface.tcl,v 1.18 2001/10/19 16:44:58 drh Exp $}

puts {<html>
<head>
  <title>The C language interface to the SQLite library</title>
</head>
<body bgcolor=white>
<h1 align=center>




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#
# Run this Tcl script to generate the sqlite.html file.
#
set rcsid {$Id: c_interface.tcl,v 1.19 2001/10/31 15:44:47 drh Exp $}

puts {<html>
<head>
  <title>The C language interface to the SQLite library</title>
</head>
<body bgcolor=white>
<h1 align=center>
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</p></dd>
<dt>SQLITE_LOCKED</dt>
<dd><p>This return code is similar to SQLITE_BUSY in that it indicates
that the database is locked.  But the source of the lock is a recursive
call to <b>sqlite_exec()</b>.  This return can only occur if you attempt
to invoke sqlite_exec() from within a callback routine of a query
from a prior invocation of sqlite_exec().  Recursive calls to
sqlite_exec() are allowed as long as no more they all read-only or do
not attempt to write the same table.
</p></dd>
<dt>SQLITE_NOMEM</dt>
<dd><p>This value is returned if a call to <b>malloc()</b> fails.
</p></dd>
<dt>SQLITE_READONLY</dt>
<dd><p>This return code indicates that an attempt was made to write to








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</p></dd>
<dt>SQLITE_LOCKED</dt>
<dd><p>This return code is similar to SQLITE_BUSY in that it indicates
that the database is locked.  But the source of the lock is a recursive
call to <b>sqlite_exec()</b>.  This return can only occur if you attempt
to invoke sqlite_exec() from within a callback routine of a query
from a prior invocation of sqlite_exec().  Recursive calls to
sqlite_exec() are allowed as long as they do
not attempt to write the same table.
</p></dd>
<dt>SQLITE_NOMEM</dt>
<dd><p>This value is returned if a call to <b>malloc()</b> fails.
</p></dd>
<dt>SQLITE_READONLY</dt>
<dd><p>This return code indicates that an attempt was made to write to
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result[2] = "host"<br>
</blockquote>

<p>Memory to hold the information returned by <b>sqlite_get_table()</b>
is obtained from malloc().  But the calling function should not try
to free this information directly.  Instead, pass the complete table
to <b>sqlite_free_table()</b> when the table is no longer needed.
It is safe to call <b>sqlite_free_table()</b> will a NULL pointer such
as would be returned if the result set is empty.</p>

<p>The <b>sqlite_get_table()</b> routine returns the same integer
result code as <b>sqlite_exec()</b>.</p>

<h2>Interrupting an SQLite operation</h2>

<p>The <b>sqlite_interrupt()</b> function can be called from a
different thread or from a signal handler to the current database
operation to exit at its first opportunity.  When this happens,
the <b>sqlite_exec()</b> routine (or the equivalent) that started
the database operation will return SQLITE_INTERRUPT.</p>

<h2>Testing for a complete SQL statement</h2>

<p>The next interface routine to SQLite is a convenience function used








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result[2] = "host"<br>
</blockquote>

<p>Memory to hold the information returned by <b>sqlite_get_table()</b>
is obtained from malloc().  But the calling function should not try
to free this information directly.  Instead, pass the complete table
to <b>sqlite_free_table()</b> when the table is no longer needed.
It is safe to call <b>sqlite_free_table()</b> with a NULL pointer such
as would be returned if the result set is empty.</p>

<p>The <b>sqlite_get_table()</b> routine returns the same integer
result code as <b>sqlite_exec()</b>.</p>

<h2>Interrupting an SQLite operation</h2>

<p>The <b>sqlite_interrupt()</b> function can be called from a
different thread or from a signal handler to cause the current database
operation to exit at its first opportunity.  When this happens,
the <b>sqlite_exec()</b> routine (or the equivalent) that started
the database operation will return SQLITE_INTERRUPT.</p>

<h2>Testing for a complete SQL statement</h2>

<p>The next interface routine to SQLite is a convenience function used
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<b>sqlite_encoding</b> character string just tells you how the library
was compiled.</p>

<h2>Changing the libraries response to locked files</h2>

<p>The <b>sqlite_busy_handler()</b> procedure can be used to register
a busy callback with an open SQLite database.  The busy callback will
be invoked whenever SQLite tries to open a locked that is locked.
The callback will typically do some other useful work, or perhaps sleep,
in order to give the lock a chance to clear.  If the callback returns
non-zero, then SQLite tries again to open the database and the cycle
repeats.  If the callback returns zero, then SQLite aborts the current
operation and returns SQLITE_BUSY.</p>

<p>The arguments to <b>sqlite_busy_handler()</b> are the opaque








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<b>sqlite_encoding</b> character string just tells you how the library
was compiled.</p>

<h2>Changing the libraries response to locked files</h2>

<p>The <b>sqlite_busy_handler()</b> procedure can be used to register
a busy callback with an open SQLite database.  The busy callback will
be invoked whenever SQLite tries to open a file that is locked.
The callback will typically do some other useful work, or perhaps sleep,
in order to give the lock a chance to clear.  If the callback returns
non-zero, then SQLite tries again to open the database and the cycle
repeats.  If the callback returns zero, then SQLite aborts the current
operation and returns SQLITE_BUSY.</p>

<p>The arguments to <b>sqlite_busy_handler()</b> are the opaque
︙︙
Changes to www/changes.tcl.
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}


proc chng {date desc} {
  puts "<DT><B>$date</B></DT>"
  puts "<DD><P><UL>$desc</UL></P></DD>"
}





chng {2001 Oct 21 (2.0.7)} {
<li>Any UTF-8 character or ISO8859 character can be used as part of
    an identifier.</li>
<li>Patches from Christian Werner to improve ODBC compatibility and to
    fix a bug in the round() function.</li>
<li>Plug some memory leaks that use to occur if malloc() failed.








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}


proc chng {date desc} {
  puts "<DT><B>$date</B></DT>"
  puts "<DD><P><UL>$desc</UL></P></DD>"
}

chng {2001 Oct ?? (2.0.8)} {
<li>Documentation updates</li>
}

chng {2001 Oct 21 (2.0.7)} {
<li>Any UTF-8 character or ISO8859 character can be used as part of
    an identifier.</li>
<li>Patches from Christian Werner to improve ODBC compatibility and to
    fix a bug in the round() function.</li>
<li>Plug some memory leaks that use to occur if malloc() failed.
︙︙
Changes to www/index.tcl. 
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#
# Run this TCL script to generate HTML for the index.html file.
#
set rcsid {$Id: index.tcl,v 1.44 2001/10/06 16:33:04 drh Exp $}

puts {<html>
<head><title>SQLite: An SQL Database Engine In A C Library</title></head>
<body bgcolor=white>
<h1 align=center>SQLite: An SQL Database Engine In A C Library</h1>
<p align=center>}
puts "This page was last modified on [lrange $rcsid 3 4] GMT<br>"




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#
# Run this TCL script to generate HTML for the index.html file.
#
set rcsid {$Id: index.tcl,v 1.45 2001/10/31 15:44:47 drh Exp $}

puts {<html>
<head><title>SQLite: An SQL Database Engine In A C Library</title></head>
<body bgcolor=white>
<h1 align=center>SQLite: An SQL Database Engine In A C Library</h1>
<p align=center>}
puts "This page was last modified on [lrange $rcsid 3 4] GMT<br>"
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<li>A description of the <a href="opcode.html">virtual machine</a> that
    SQLite uses to access the database.</li>
</ul>
</p>

<p>The SQLite source code is 35% comment.  These comments are
another important source of information. </p>

}

puts {
<table align="right">
<tr><td align="center">
<a href="http://www.yahoogroups.com/subscribe/sqlite">
<img src="http://www.egroups.com/img/ui/join.gif" border=0 /><br />
Click to subscribe to sqlite</a>
</td></tr>
</table>
<a name="mailinglist" />
<h2>Mailing List</h2>
<p>A mailing list has been set up on yahooGroups for discussion of
SQLite design issues or for asking questions about SQLite.</p>
}


















puts {<h2>Building From Source</h2>}

puts {
<p>To build sqlite under Unix, just unwrap the tarball, create a separate
build directory, run configure from the build directory and then
type "make".  For example:</p>








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<li>A description of the <a href="opcode.html">virtual machine</a> that
    SQLite uses to access the database.</li>
</ul>
</p>

<p>The SQLite source code is 35% comment.  These comments are
another important source of information. </p>

}

puts {
<table align="right">
<tr><td align="center">
<a href="http://www.yahoogroups.com/subscribe/sqlite">
<img src="http://www.egroups.com/img/ui/join.gif" border=0 /><br />
Click to subscribe to sqlite</a>
</td></tr>
</table>
<a name="mailinglist" />
<h2>Mailing List</h2>
<p>A mailing list has been set up on yahooGroups for discussion of
SQLite design issues or for asking questions about SQLite.</p>
}

puts {<h2>Professional Support and Custom Modifications</h2>}

puts {
<p>
If you would like professional support for SQLite
or if you want custom modifications to SQLite preformed by the
original author, these services are available for a modest fee.
For additional information contact:</p>

<blockquote>
D. Richard Hipp <br />
Hwaci - Applied Software Research <br />
704.948.4565 <br />
<a href="mailto:drh@hwaci.com">drh@hwaci.com</a>
</blockquote>
}

puts {<h2>Building From Source</h2>}

puts {
<p>To build sqlite under Unix, just unwrap the tarball, create a separate
build directory, run configure from the build directory and then
type "make".  For example:</p>
︙︙
Changes to www/speed.tcl. 
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#
# Run this Tcl script to generate the speed.html file.
#
set rcsid {$Id: speed.tcl,v 1.3 2001/09/28 23:11:24 drh Exp $ }

puts {<html>
<head>
  <title>Database Speed Comparison: SQLite versus PostgreSQL</title>
</head>
<body bgcolor=white>
<h1 align=center>




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#
# Run this Tcl script to generate the speed.html file.
#
set rcsid {$Id: speed.tcl,v 1.4 2001/10/31 15:44:48 drh Exp $ }

puts {<html>
<head>
  <title>Database Speed Comparison: SQLite versus PostgreSQL</title>
</head>
<body bgcolor=white>
<h1 align=center>
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SQLite 1.0:   real   0.03   user   0.00   sys   0.02
SQLite 2.0:   real   3.12   user   0.02   sys   0.31
</pre></blockquote>

<p>
SQLite 2.0 is much slower at dropping tables.  This may be because
both SQLite 1.0 and PostgreSQL can drop a table simply by unlinking
or renaming a file, since that both use one or more files per table.
SQLite 2.0, on the other hand, uses a single file for the entire
database, so dropping a table involves moving lots of page of that
file to the free-list, which takes time.
</p>

}
puts {
<p><hr /></p>
<p><a href="index.html"><img src="/goback.jpg" border=0 />
Back to the SQLite Home Page</a>
</p>

</body></html>}








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SQLite 1.0:   real   0.03   user   0.00   sys   0.02
SQLite 2.0:   real   3.12   user   0.02   sys   0.31
</pre></blockquote>

<p>
SQLite 2.0 is much slower at dropping tables.  This may be because
both SQLite 1.0 and PostgreSQL can drop a table simply by unlinking
or renaming a file, since both store database tables in separate files.
SQLite 2.0, on the other hand, uses a single file for the entire
database, so dropping a table involves moving lots of page of that
file to the free-list, which takes time.
</p>

}
puts {
<p><hr /></p>
<p><a href="index.html"><img src="/goback.jpg" border=0 />
Back to the SQLite Home Page</a>
</p>

</body></html>}