modernc.org/cc@v1.0.1/v2/testdata/_sqlite/test/tempdb2.test (about)

     1  # 2016 March 3
     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  set testdir [file dirname $argv0]
    13  source $testdir/tester.tcl
    14  set testprefix tempdb2
    15  
    16  db close
    17  sqlite3 db ""
    18  
    19  proc int2str {i} { string range [string repeat "$i." 450] 0 899 }
    20  db func int2str int2str
    21  
    22  #-------------------------------------------------------------------------
    23  #
    24  #  1.1: Write a big transaction to the db. One so large that it forces
    25  #       the file to be created and the cache flushed to disk on COMMIT.
    26  #
    27  #  1.2: Write a small transaction - one small enough that it remains in
    28  #       memory on COMMIT. All the pages of table [t1] are now dirty.
    29  #
    30  #  1.3: Delete the contents of [t1]. This moves all of its leaves to the
    31  #       free-list and causes the btree layer to call PagerDontWrite() on
    32  #       each of them.
    33  #
    34  #       Then do a big update on table [t2]. So big that the former leaves
    35  #       of [t1] are forced out of the cache. Then roll back the transaction.
    36  #       If the PagerDontWrite() calls are honoured and the data is not written
    37  #       to disk, the update made in test 1.2 will be lost at this point. Or, if
    38  #       they are ignored (as they should be for temp databases), the update
    39  #       will be safely written out to disk before the cache entries are
    40  #       discarded.
    41  #
    42  do_execsql_test 1.1 {
    43    PRAGMA page_size=1024;
    44    PRAGMA cache_size=50;
    45  
    46    BEGIN;
    47      CREATE TABLE t1(a INTEGER PRIMARY KEY, b);
    48      INSERT INTO t1 VALUES(1, int2str(1));
    49      INSERT INTO t1 VALUES(2, int2str(1));
    50      INSERT INTO t1 VALUES(3, int2str(1));
    51  
    52      CREATE TABLE t2(a INTEGER PRIMARY KEY, b);
    53      WITH c(x) AS ( VALUES(1) UNION ALL SELECT x+1 FROM c WHERE x<100 ) 
    54      INSERT INTO t2 SELECT x, int2str(x) FROM c;
    55    COMMIT;
    56  
    57    PRAGMA lock_status;
    58  } {main unlocked temp closed}
    59  
    60  do_execsql_test 1.2 {
    61    UPDATE t1 SET b=int2str(2);
    62    SELECT b=int2str(2) FROM t1
    63  } {1 1 1}
    64  
    65  do_execsql_test 1.3 {
    66    BEGIN;
    67      DELETE FROM t1;
    68      UPDATE t2 SET b=int2str(a+1);
    69    ROLLBACK;
    70  }
    71  
    72  do_execsql_test 1.4 {
    73    SELECT b=int2str(2) FROM t1
    74  } {1 1 1}
    75  
    76  finish_test