Updated: 2022/Sep/29
Please read Privacy Policy. It's for your privacy.
SQLITE_DBSTATUS_LOOKASIDE_USED(3) Library Functions Manual
NAME
SQLITE_DBSTATUS_LOOKASIDE_USED, SQLITE_DBSTATUS_CACHE_USED,
SQLITE_DBSTATUS_SCHEMA_USED, SQLITE_DBSTATUS_STMT_USED,
SQLITE_DBSTATUS_LOOKASIDE_HIT, SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE,
SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL, SQLITE_DBSTATUS_CACHE_HIT,
SQLITE_DBSTATUS_CACHE_MISS, SQLITE_DBSTATUS_CACHE_WRITE,
SQLITE_DBSTATUS_DEFERRED_FKS, SQLITE_DBSTATUS_CACHE_USED_SHARED,
SQLITE_DBSTATUS_CACHE_SPILL, SQLITE_DBSTATUS_MAX - status parameters for
database connections
SYNOPSIS
#include <sqlite3.h>
#define SQLITE_DBSTATUS_LOOKASIDE_USED
#define SQLITE_DBSTATUS_CACHE_USED
#define SQLITE_DBSTATUS_SCHEMA_USED
#define SQLITE_DBSTATUS_STMT_USED
#define SQLITE_DBSTATUS_LOOKASIDE_HIT
#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE
#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL
#define SQLITE_DBSTATUS_CACHE_HIT
#define SQLITE_DBSTATUS_CACHE_MISS
#define SQLITE_DBSTATUS_CACHE_WRITE
#define SQLITE_DBSTATUS_DEFERRED_FKS
#define SQLITE_DBSTATUS_CACHE_USED_SHARED
#define SQLITE_DBSTATUS_CACHE_SPILL
#define SQLITE_DBSTATUS_MAX
DESCRIPTION
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.
IMPLEMENTATION NOTES
These declarations were extracted from the interface documentation at
line 8540.
#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 */
SEE ALSO
sqlite3_db_status(3)
NetBSD 10.99 August 24, 2023 NetBSD 10.99