Status Parameters for database connections

From 18657a960e125336f704ea058e25c27bd3900dcb Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 5 May 2024 19:28:19 +0200 Subject: Adding upstream version 3.40.1. Signed-off-by: Daniel Baumann --- www/c3ref/c_dbstatus_options.html | 263 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 263 insertions(+) create mode 100644 www/c3ref/c_dbstatus_options.html (limited to 'www/c3ref/c_dbstatus_options.html') diff --git a/www/c3ref/c_dbstatus_options.html b/www/c3ref/c_dbstatus_options.html new file mode 100644 index 0000000..96716c6 --- /dev/null +++ b/www/c3ref/c_dbstatus_options.html @@ -0,0 +1,263 @@ + + + + + +Status Parameters for database connections + + + +

+ +

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Choose any three. +

+ + +

+ +

+ + +

SQLite C Interface

Status Parameters for database connections

+#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 */
+

+These constants are the available integer "verbs" that can be passed as +the second argument to the sqlite3_db_status() interface.

+ +

New verbs may be added in future releases of SQLite. Existing verbs +might be discontinued. Applications should check the return code from +sqlite3_db_status() to make sure that the call worked. +The sqlite3_db_status() interface will return a non-zero error code +if a discontinued or unsupported verb is invoked.

+ +

SQLITE_DBSTATUS_LOOKASIDE_USED

This parameter returns the number of lookaside memory slots currently +checked out.

SQLITE_DBSTATUS_LOOKASIDE_HIT

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.

+ +

SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE

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.

+ +

SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL

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.

+ +

SQLITE_DBSTATUS_CACHE_USED

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.

+ +

SQLITE_DBSTATUS_CACHE_USED_SHARED

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.

+ +

SQLITE_DBSTATUS_SCHEMA_USED

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 ATTACH-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 +shared cache mode being enabled. +The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.

+ +

SQLITE_DBSTATUS_STMT_USED

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. +

SQLITE_DBSTATUS_CACHE_HIT

This parameter returns the number of pager cache hits that have +occurred. The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT +is always 0. +

SQLITE_DBSTATUS_CACHE_MISS

This parameter returns the number of pager cache misses that have +occurred. The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS +is always 0. +

SQLITE_DBSTATUS_CACHE_WRITE

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. +

SQLITE_DBSTATUS_CACHE_SPILL

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. +

SQLITE_DBSTATUS_DEFERRED_FKS

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. +

See also lists of + Objects, + Constants, and + Functions.

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