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diff --git a/www/c3ref/c_dbstatus_options.html b/www/c3ref/c_dbstatus_options.html new file mode 100644 index 0000000..21d027f --- /dev/null +++ b/www/c3ref/c_dbstatus_options.html @@ -0,0 +1,263 @@ +<!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. 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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="../c3ref/objlist.html">Objects</a>, + <a href="../c3ref/constlist.html">Constants</a>, and + <a href="../c3ref/funclist.html">Functions</a>.</p> + |