github.com/jdgcs/sqlite3@v1.12.1-0.20210908114423-bc5f96e4dd51/testdata/tcl/shrink.test (about)

     1  # 2011 November 16
     2  #
     3  # The author disclaims copyright to this source code.  In place of
     4  # a legal notice, here is a blessing:
     5  #
     6  #    May you do good and not evil.
     7  #    May you find forgiveness for yourself and forgive others.
     8  #    May you share freely, never taking more than you give.
     9  #
    10  #***********************************************************************
    11  #
    12  # This file contains test cases for sqlite3_db_release_memory and
    13  # the PRAGMA shrink_memory statement.
    14  #
    15  
    16  set testdir [file dirname $argv0]
    17  source $testdir/tester.tcl
    18  test_set_config_pagecache 0 0
    19  
    20  unset -nocomplain baseline
    21  do_test shrink-1.1 {
    22    db eval {
    23      PRAGMA cache_size = 2000;
    24      CREATE TABLE t1(x,y);
    25      INSERT INTO t1 VALUES(randomblob(1000000),1);
    26    }
    27    set ::baseline sqlite3_memory_used
    28    # EVIDENCE-OF: R-58814-63508 The sqlite3_db_release_memory(D) interface
    29    # attempts to free as much heap memory as possible from database
    30    # connection D.
    31    sqlite3_db_release_memory db
    32    expr {$::baseline > [sqlite3_memory_used]+500000}
    33  } {1}
    34  do_test shrink-1.2 {
    35    set baseline [sqlite3_memory_used]
    36    db eval {
    37      UPDATE t1 SET y=y+1;
    38    }
    39    expr {$::baseline+500000 < [sqlite3_memory_used]}
    40  } {1}
    41  do_test shrink-1.3 {
    42    set baseline [sqlite3_memory_used]
    43    db eval {PRAGMA shrink_memory}
    44    expr {$::baseline > [sqlite3_memory_used]+500000}
    45  } {1}
    46  
    47  test_restore_config_pagecache
    48  finish_test