1.Dd March 11, 2017 2.Dt SQLITE_DBSTATUS_LOOKASIDE_USED 3 3.Os 4.Sh NAME 5.Nm SQLITE_DBSTATUS_LOOKASIDE_USED , 6.Nm SQLITE_DBSTATUS_CACHE_USED , 7.Nm SQLITE_DBSTATUS_SCHEMA_USED , 8.Nm SQLITE_DBSTATUS_STMT_USED , 9.Nm SQLITE_DBSTATUS_LOOKASIDE_HIT , 10.Nm SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE , 11.Nm SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL , 12.Nm SQLITE_DBSTATUS_CACHE_HIT , 13.Nm SQLITE_DBSTATUS_CACHE_MISS , 14.Nm SQLITE_DBSTATUS_CACHE_WRITE , 15.Nm SQLITE_DBSTATUS_DEFERRED_FKS , 16.Nm SQLITE_DBSTATUS_CACHE_USED_SHARED , 17.Nm SQLITE_DBSTATUS_MAX 18.Nd Status Parameters for database connections 19.Sh SYNOPSIS 20.Fd #define SQLITE_DBSTATUS_LOOKASIDE_USED 21.Fd #define SQLITE_DBSTATUS_CACHE_USED 22.Fd #define SQLITE_DBSTATUS_SCHEMA_USED 23.Fd #define SQLITE_DBSTATUS_STMT_USED 24.Fd #define SQLITE_DBSTATUS_LOOKASIDE_HIT 25.Fd #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 26.Fd #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 27.Fd #define SQLITE_DBSTATUS_CACHE_HIT 28.Fd #define SQLITE_DBSTATUS_CACHE_MISS 29.Fd #define SQLITE_DBSTATUS_CACHE_WRITE 30.Fd #define SQLITE_DBSTATUS_DEFERRED_FKS 31.Fd #define SQLITE_DBSTATUS_CACHE_USED_SHARED 32.Fd #define SQLITE_DBSTATUS_MAX 33.Sh DESCRIPTION 34These constants are the available integer "verbs" that can be passed 35as the second argument to the sqlite3_db_status() 36interface. 37.Pp 38New verbs may be added in future releases of SQLite. 39Existing verbs might be discontinued. 40Applications should check the return code from sqlite3_db_status() 41to make sure that the call worked. 42The sqlite3_db_status() interface will return a 43non-zero error code if a discontinued or unsupported verb is invoked. 44.Bl -tag -width Ds 45.It SQLITE_DBSTATUS_LOOKASIDE_USED 46This parameter returns the number of lookaside memory slots currently 47checked out. 48.It SQLITE_DBSTATUS_LOOKASIDE_HIT 49This parameter returns the number malloc attempts that were satisfied 50using lookaside memory. 51Only the high-water value is meaningful; the current value is always 52zero. 53.It SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 54This parameter returns the number malloc attempts that might have been 55satisfied using lookaside memory but failed due to the amount of memory 56requested being larger than the lookaside slot size. 57Only the high-water value is meaningful; the current value is always 58zero. 59.It SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 60This parameter returns the number malloc attempts that might have been 61satisfied using lookaside memory but failed due to all lookaside memory 62already being in use. 63Only the high-water value is meaningful; the current value is always 64zero. 65.It SQLITE_DBSTATUS_CACHE_USED 66This parameter returns the approximate number of bytes of heap memory 67used by all pager caches associated with the database connection. 68The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 690. 70.It SQLITE_DBSTATUS_CACHE_USED_SHARED 71This parameter is similar to DBSTATUS_CACHE_USED, except that if a 72pager cache is shared between two or more connections the bytes of 73heap memory used by that pager cache is divided evenly between the 74attached connections. 75In other words, if none of the pager caches associated with the database 76connection are shared, this request returns the same value as DBSTATUS_CACHE_USED. 77Or, if one or more or the pager caches are shared, the value returned 78by this call will be smaller than that returned by DBSTATUS_CACHE_USED. 79The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED_SHARED 80is always 0. 81.It SQLITE_DBSTATUS_SCHEMA_USED 82This parameter returns the approximate number of bytes of heap memory 83used to store the schema for all databases associated with the connection 84- main, temp, and any ATTACH-ed databases. 85The full amount of memory used by the schemas is reported, even if 86the schema memory is shared with other database connections due to 87shared cache mode being enabled. 88The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 890. 90.It SQLITE_DBSTATUS_STMT_USED 91This parameter returns the approximate number of bytes of heap and 92lookaside memory used by all prepared statements associated with the 93database connection. 94The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 950. 96.It SQLITE_DBSTATUS_CACHE_HIT 97This parameter returns the number of pager cache hits that have occurred. 98The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT is always 990. 100.It SQLITE_DBSTATUS_CACHE_MISS 101This parameter returns the number of pager cache misses that have occurred. 102The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS is always 1030. 104.It SQLITE_DBSTATUS_CACHE_WRITE 105This parameter returns the number of dirty cache entries that have 106been written to disk. 107Specifically, the number of pages written to the wal file in wal mode 108databases, or the number of pages written to the database file in rollback 109mode databases. 110Any pages written as part of transaction rollback or database recovery 111operations are not included. 112If an IO or other error occurs while writing a page to disk, the effect 113on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined. 114The highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 1150. 116.It SQLITE_DBSTATUS_DEFERRED_FKS 117This parameter returns zero for the current value if and only if all 118foreign key constraints (deferred or immediate) have been resolved. 119The highwater mark is always 0. 120.El 121.Pp 122.Sh SEE ALSO 123.Xr sqlite3_db_status 3 124