239 lines
9.8 KiB
HTML
239 lines
9.8 KiB
HTML
<!DOCTYPE html>
|
|
<html><head>
|
|
<meta name="viewport" content="width=device-width, initial-scale=1.0">
|
|
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
|
|
<link href="../sqlite.css" rel="stylesheet">
|
|
<title>Status Parameters for database connections</title>
|
|
<!-- path=../ -->
|
|
</head>
|
|
<body>
|
|
<div class=nosearch>
|
|
<a href="../index.html">
|
|
<img class="logo" src="../images/sqlite370_banner.gif" alt="SQLite" border="0">
|
|
</a>
|
|
<div><!-- IE hack to prevent disappearing logo --></div>
|
|
<div class="tagline desktoponly">
|
|
Small. Fast. Reliable.<br>Choose any three.
|
|
</div>
|
|
<div class="menu mainmenu">
|
|
<ul>
|
|
<li><a href="../index.html">Home</a>
|
|
<li class='mobileonly'><a href="javascript:void(0)" onclick='toggle_div("submenu")'>Menu</a>
|
|
<li class='wideonly'><a href='../about.html'>About</a>
|
|
<li class='desktoponly'><a href="../docs.html">Documentation</a>
|
|
<li class='desktoponly'><a href="../download.html">Download</a>
|
|
<li class='wideonly'><a href='../copyright.html'>License</a>
|
|
<li class='desktoponly'><a href="../support.html">Support</a>
|
|
<li class='desktoponly'><a href="../prosupport.html">Purchase</a>
|
|
<li class='search' id='search_menubutton'>
|
|
<a href="javascript:void(0)" onclick='toggle_search()'>Search</a>
|
|
</ul>
|
|
</div>
|
|
<div class="menu submenu" id="submenu">
|
|
<ul>
|
|
<li><a href='../about.html'>About</a>
|
|
<li><a href='../docs.html'>Documentation</a>
|
|
<li><a href='../download.html'>Download</a>
|
|
<li><a href='../support.html'>Support</a>
|
|
<li><a href='../prosupport.html'>Purchase</a>
|
|
</ul>
|
|
</div>
|
|
<div class="searchmenu" id="searchmenu">
|
|
<form method="GET" action="../search">
|
|
<select name="s" id="searchtype">
|
|
<option value="d">Search Documentation</option>
|
|
<option value="c">Search Changelog</option>
|
|
</select>
|
|
<input type="text" name="q" id="searchbox" value="">
|
|
<input type="submit" value="Go">
|
|
</form>
|
|
</div>
|
|
</div>
|
|
<script>
|
|
function toggle_div(nm) {
|
|
var w = document.getElementById(nm);
|
|
if( w.style.display=="block" ){
|
|
w.style.display = "none";
|
|
}else{
|
|
w.style.display = "block";
|
|
}
|
|
}
|
|
function toggle_search() {
|
|
var w = document.getElementById("searchmenu");
|
|
if( w.style.display=="block" ){
|
|
w.style.display = "none";
|
|
} else {
|
|
w.style.display = "block";
|
|
setTimeout(function(){
|
|
document.getElementById("searchbox").focus()
|
|
}, 30);
|
|
}
|
|
}
|
|
function div_off(nm){document.getElementById(nm).style.display="none";}
|
|
window.onbeforeunload = function(e){div_off("submenu");}
|
|
/* Disable the Search feature if we are not operating from CGI, since */
|
|
/* Search is accomplished using CGI and will not work without it. */
|
|
if( !location.origin || !location.origin.match || !location.origin.match(/http/) ){
|
|
document.getElementById("search_menubutton").style.display = "none";
|
|
}
|
|
/* Used by the Hide/Show button beside syntax diagrams, to toggle the */
|
|
function hideorshow(btn,obj){
|
|
var x = document.getElementById(obj);
|
|
var b = document.getElementById(btn);
|
|
if( x.style.display!='none' ){
|
|
x.style.display = 'none';
|
|
b.innerHTML='show';
|
|
}else{
|
|
x.style.display = '';
|
|
b.innerHTML='hide';
|
|
}
|
|
return false;
|
|
}
|
|
</script>
|
|
</div>
|
|
<!-- keywords: {SQLITE_DBSTATUS options} SQLITE_DBSTATUS_CACHE_HIT SQLITE_DBSTATUS_CACHE_MISS SQLITE_DBSTATUS_CACHE_SPILL SQLITE_DBSTATUS_CACHE_USED SQLITE_DBSTATUS_CACHE_USED_SHARED SQLITE_DBSTATUS_CACHE_WRITE SQLITE_DBSTATUS_DEFERRED_FKS SQLITE_DBSTATUS_LOOKASIDE_HIT SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE SQLITE_DBSTATUS_LOOKASIDE_USED SQLITE_DBSTATUS_MAX SQLITE_DBSTATUS_SCHEMA_USED SQLITE_DBSTATUS_STMT_USED -->
|
|
<div class=nosearch>
|
|
<a href="intro.html"><h2>SQLite C Interface</h2></a>
|
|
<h2>Status Parameters for database connections</h2>
|
|
</div>
|
|
<blockquote><pre>
|
|
#define SQLITE_DBSTATUS_LOOKASIDE_USED 0
|
|
#define SQLITE_DBSTATUS_CACHE_USED 1
|
|
#define SQLITE_DBSTATUS_SCHEMA_USED 2
|
|
#define SQLITE_DBSTATUS_STMT_USED 3
|
|
#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
|
|
#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
|
|
#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
|
|
#define SQLITE_DBSTATUS_CACHE_HIT 7
|
|
#define SQLITE_DBSTATUS_CACHE_MISS 8
|
|
#define SQLITE_DBSTATUS_CACHE_WRITE 9
|
|
#define SQLITE_DBSTATUS_DEFERRED_FKS 10
|
|
#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11
|
|
#define SQLITE_DBSTATUS_CACHE_SPILL 12
|
|
#define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */
|
|
</pre></blockquote>
|
|
<p>
|
|
These constants are the available integer "verbs" that can be passed as
|
|
the second argument to the <a href="../c3ref/db_status.html">sqlite3_db_status()</a> interface.</p>
|
|
|
|
<p>New verbs may be added in future releases of SQLite. Existing verbs
|
|
might be discontinued. Applications should check the return code from
|
|
<a href="../c3ref/db_status.html">sqlite3_db_status()</a> to make sure that the call worked.
|
|
The <a href="../c3ref/db_status.html">sqlite3_db_status()</a> interface will return a non-zero error code
|
|
if a discontinued or unsupported verb is invoked.</p>
|
|
|
|
<p><dl>
|
|
<a name="sqlitedbstatuslookasideused"></a>
|
|
<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
|
|
<dd>This parameter returns the number of lookaside memory slots currently
|
|
checked out.</dd></p>
|
|
|
|
<p><a name="sqlitedbstatuslookasidehit"></a>
|
|
<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
|
|
<dd>This parameter returns the number of malloc attempts that were
|
|
satisfied using lookaside memory. Only the high-water value is meaningful;
|
|
the current value is always zero.</p>
|
|
|
|
<p><a name="sqlitedbstatuslookasidemisssize"></a>
|
|
|
|
<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
|
|
<dd>This parameter returns the number malloc attempts that might have
|
|
been satisfied using lookaside memory but failed due to the amount of
|
|
memory requested being larger than the lookaside slot size.
|
|
Only the high-water value is meaningful;
|
|
the current value is always zero.</p>
|
|
|
|
<p><a name="sqlitedbstatuslookasidemissfull"></a>
|
|
|
|
<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
|
|
<dd>This parameter returns the number malloc attempts that might have
|
|
been satisfied using lookaside memory but failed due to all lookaside
|
|
memory already being in use.
|
|
Only the high-water value is meaningful;
|
|
the current value is always zero.</p>
|
|
|
|
<p><a name="sqlitedbstatuscacheused"></a>
|
|
<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
|
|
<dd>This parameter returns the approximate number of bytes of heap
|
|
memory used by all pager caches associated with the database connection.
|
|
The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.</p>
|
|
|
|
<p><a name="sqlitedbstatuscacheusedshared"></a>
|
|
|
|
<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>
|
|
<dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a
|
|
pager cache is shared between two or more connections the bytes of heap
|
|
memory used by that pager cache is divided evenly between the attached
|
|
connections. In other words, if none of the pager caches associated
|
|
with the database connection are shared, this request returns the same
|
|
value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are
|
|
shared, the value returned by this call will be smaller than that returned
|
|
by DBSTATUS_CACHE_USED. The highwater mark associated with
|
|
SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.</p>
|
|
|
|
<p><a name="sqlitedbstatusschemaused"></a>
|
|
<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
|
|
<dd>This parameter returns the approximate number of bytes of heap
|
|
memory used to store the schema for all databases associated
|
|
with the connection - main, temp, and any <a href="../lang_attach.html">ATTACH</a>-ed databases.
|
|
The full amount of memory used by the schemas is reported, even if the
|
|
schema memory is shared with other database connections due to
|
|
<a href="../sharedcache.html">shared cache mode</a> being enabled.
|
|
The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.</p>
|
|
|
|
<p><a name="sqlitedbstatusstmtused"></a>
|
|
<dt>SQLITE_DBSTATUS_STMT_USED</dt>
|
|
<dd>This parameter returns the approximate number of bytes of heap
|
|
and lookaside memory used by all prepared statements associated with
|
|
the database connection.
|
|
The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
|
|
</dd></p>
|
|
|
|
<p><a name="sqlitedbstatuscachehit"></a>
|
|
<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
|
|
<dd>This parameter returns the number of pager cache hits that have
|
|
occurred. The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
|
|
is always 0.
|
|
</dd></p>
|
|
|
|
<p><a name="sqlitedbstatuscachemiss"></a>
|
|
<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
|
|
<dd>This parameter returns the number of pager cache misses that have
|
|
occurred. The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
|
|
is always 0.
|
|
</dd></p>
|
|
|
|
<p><a name="sqlitedbstatuscachewrite"></a>
|
|
<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
|
|
<dd>This parameter returns the number of dirty cache entries that have
|
|
been written to disk. Specifically, the number of pages written to the
|
|
wal file in wal mode databases, or the number of pages written to the
|
|
database file in rollback mode databases. Any pages written as part of
|
|
transaction rollback or database recovery operations are not included.
|
|
If an IO or other error occurs while writing a page to disk, the effect
|
|
on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined. The
|
|
highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
|
|
</dd></p>
|
|
|
|
<p><a name="sqlitedbstatuscachespill"></a>
|
|
<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt>
|
|
<dd>This parameter returns the number of dirty cache entries that have
|
|
been written to disk in the middle of a transaction due to the page
|
|
cache overflowing. Transactions are more efficient if they are written
|
|
to disk all at once. When pages spill mid-transaction, that introduces
|
|
additional overhead. This parameter can be used help identify
|
|
inefficiencies that can be resolved by increasing the cache size.
|
|
</dd></p>
|
|
|
|
<p><a name="sqlitedbstatusdeferredfks"></a>
|
|
<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
|
|
<dd>This parameter returns zero for the current value if and only if
|
|
all foreign key constraints (deferred or immediate) have been
|
|
resolved. The highwater mark is always 0.
|
|
</dd>
|
|
</dl>
|
|
</p><p>See also lists of
|
|
<a href="objlist.html">Objects</a>,
|
|
<a href="constlist.html">Constants</a>, and
|
|
<a href="funclist.html">Functions</a>.</p>
|