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SQLITE3_SOFT_HEAP_LIMIT64(3)                          Library Functions Manual

NAME
     sqlite3_soft_heap_limit64, sqlite3_hard_heap_limit64 - impose a limit on
     heap size

SYNOPSIS
     #include <sqlite3.h>

     sqlite3_int64
     sqlite3_soft_heap_limit64(sqlite3_int64 N);

     sqlite3_int64
     sqlite3_hard_heap_limit64(sqlite3_int64 N);

DESCRIPTION
     These interfaces impose limits on the amount of heap memory that will be
     by all database connections within a single process.

     The sqlite3_soft_heap_limit64() interface sets and/or queries the soft
     limit on the amount of heap memory that may be allocated by SQLite.
     SQLite strives to keep heap memory utilization below the soft heap limit
     by reducing the number of pages held in the page cache as heap memory
     usages approaches the limit.  The soft heap limit is "soft" because even
     though SQLite strives to stay below the limit, it will exceed the limit
     rather than generate an SQLITE_NOMEM error.  In other words, the soft
     heap limit is advisory only.

     The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of N
     bytes on the amount of memory that will be allocated.  The
     sqlite3_hard_heap_limit64(N) interface is similar to
     sqlite3_soft_heap_limit64(N) except that memory allocations will fail
     when the hard heap limit is reached.

     The return value from both sqlite3_soft_heap_limit64() and
     sqlite3_hard_heap_limit64() is the size of the heap limit prior to the
     call, or negative in the case of an error.  If the argument N is negative
     then no change is made to the heap limit.  Hence, the current size of
     heap limits can be determined by invoking sqlite3_soft_heap_limit64(-1)
     or sqlite3_hard_heap_limit(-1).

     Setting the heap limits to zero disables the heap limiter mechanism.

     The soft heap limit may not be greater than the hard heap limit.  If the
     hard heap limit is enabled and if sqlite3_soft_heap_limit(N) is invoked
     with a value of N that is greater than the hard heap limit, the soft heap
     limit is set to the value of the hard heap limit.  The soft heap limit is
     automatically enabled whenever the hard heap limit is enabled.  When
     sqlite3_hard_heap_limit64(N) is invoked and the soft heap limit is
     outside the range of 1..N, then the soft heap limit is set to N.
     Invoking sqlite3_soft_heap_limit64(0) when the hard heap limit is enabled
     makes the soft heap limit equal to the hard heap limit.

     The memory allocation limits can also be adjusted using PRAGMA
     soft_heap_limit and PRAGMA hard_heap_limit.

     The heap limits are not enforced in the current implementation if one or
     more of following conditions are true:

     ⊕   The limit value is set to zero.

     ⊕   Memory accounting is disabled using a combination of the
         sqlite3_config(SQLITE_CONFIG_MEMSTATUS,...) start-time option and the
         SQLITE_DEFAULT_MEMSTATUS compile-time option.

     ⊕   An alternative page cache implementation is specified using
         sqlite3_config(SQLITE_CONFIG_PCACHE2,...).

     ⊕   The page cache allocates from its own memory pool supplied by
         sqlite3_config(SQLITE_CONFIG_PAGECACHE,...) rather than from the
         heap.

     The circumstances under which SQLite will enforce the heap limits may
     changes in future releases of SQLite.

IMPLEMENTATION NOTES
     These declarations were extracted from the interface documentation at
     line 6865.

     SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
     SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N);

SEE ALSO
     sqlite3_config(3), SQLITE_CONFIG_SINGLETHREAD(3), SQLITE_OK(3)

NetBSD 10.99                    August 24, 2023                   NetBSD 10.99