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Preparing for the 2.4.0 release. (CVS 426)

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FossilOrigin-Name: 9f5b241cb2fc89f66d3762b4b4978b8e114caf53
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drh
2002-03-11 02:06:13 +00:00
parent 7218ac7098
commit 28b4e4890b
11 changed files with 546 additions and 223 deletions
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61
www/lang.tcl
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@ -1,7 +1,7 @@
#
# Run this Tcl script to generate the sqlite.html file.
#
set rcsid {$Id: lang.tcl,v 1.27 2002/03/04 02:26:17 drh Exp $}
set rcsid {$Id: lang.tcl,v 1.28 2002/03/11 02:06:14 drh Exp $}
puts {<html>
<head>
@ -817,13 +817,19 @@ with caution.</p>
<p>The current implementation supports the following pragmas:</p>
<ul>
<li><p><b>PRAGMA cache_size = </b><i>Number-of-pages</i><b>;</b></p>
<p>Change the maximum number of database disk pages that SQLite
will hold in memory at once. Each page uses about 1.5K of RAM.
The default cache size is 100. If you are doing UPDATEs or DELETEs
<li><p><b>PRAGMA cache_size;
<br>PRAGMA cache_size = </b><i>Number-of-pages</i><b>;</b></p>
<p>Query or change the maximum number of database disk pages that SQLite
will hold in memory at once. Each page uses about 1.5K of memory.
The default cache size is 2000. If you are doing UPDATEs or DELETEs
that change many rows of a database and you do not mind if SQLite
uses more memory, you can increase the cache size for a possible speed
improvement.</p></li>
improvement.</p>
<p>When you change the cache size using the cache_size pragma, the
change only endures for the current session. The cache size reverts
to the default value when the database is closed and reopened. Use
the <b>default_cache_size</b> pragma to check the cache size permanently
</p></li>
<li><p><b>PRAGMA count_changes = ON;
<br>PRAGMA count_changes = OFF;</b></p>
@ -831,6 +837,39 @@ with caution.</p>
be invoked once for each DELETE, INSERT, or UPDATE operation. The
argument is the number of rows that were changed.</p>
<li><p><b>PRAGMA default_cache_size;
<br>PRAGMA default_cache_size = </b><i>Number-of-pages</i><b>;</b></p>
<p>Query or change the maximum number of database disk pages that SQLite
will hold in memory at once. Each page uses about 1.5K of memory.
This pragma works like the <b>cache_size</b> pragma with the addition
feature that it changes the cache size persistently. With this pragma,
you can set the cache size once and that setting is retained and reused
everytime you reopen the database.</p></li>
<li><p><b>PRAGMA default_synchronous;
<br>PRAGMA default_synchronous = ON;
<br>PRAGMA default_synchronous = OFF;</b></p>
<p>Query or change the setting of the "synchronous" flag in
the database. When synchronous is on (the default), the SQLite database
engine will pause at critical moments to make sure that data has actually
be written to the disk surface. (In other words, it invokes the
equivalent of the <b>fsync()</b> system call.) In synchronous mode,
an SQLite database should be fully recoverable even if the operating
system crashes or power is interrupted unexpectedly. The penalty for
this assurance is that some database operations take longer because the
engine has to wait on the (relatively slow) disk drive. The alternative
is to turn synchronous off. With synchronous off, SQLite continues
processing as soon as it has handed data off to the operating system.
If the application running SQLite crashes, the data will be safe, but
the database could (in theory) become corrupted if the operating system
crashes or the computer suddenly loses power. On the other hand, some
operations are as much as 50 or more times faster with synchronous off.
</p>
<p>This pragma changes the synchronous mode persistently. Once changed,
the mode stays as set even if the database is closed and reopened. The
<b>synchronous</b> pragma does the same thing but only applies the setting
to the current session.</p>
<li><p><b>PRAGMA empty_result_callbacks = ON;
<br>PRAGMA empty_result_callbacks = OFF;</b></p>
<p>When on, the EMPTY_RESULT_CALLBACKS pragma causes the callback
@ -873,6 +912,16 @@ with caution.</p>
a description of all problems. If everything is in order, "ok" is
returned.</p>
<li><p><b>PRAGMA synchronous;
<br>PRAGMA synchronous = ON;
<br>PRAGMA synchronous = OFF;</b></p>
<p>Query or change the setting of the "synchronous" flag in
the database for the duration of the current database connect.
The synchronous flag reverts to its default value when the database
is closed and reopened. For additional information on the synchronous
flag, see the description of the <b>default_synchronous</b> pragma.</p>
</li>
<li><p><b>PRAGMA table_info(</b><i>table-name</i><b>);</b></p>
<p>For each column in the named table, invoke the callback function
once with information about that column, including the column name,