gitlab.com/CoiaPrant/sqlite3@v1.19.1/testdata/tcl/analyze4.test (about)

     1  # 2011 January 04
     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 implements regression tests for SQLite library. This file 
    13  # implements tests for ANALYZE to verify that multiple rows containing
    14  # a NULL value count as distinct rows for the purposes of analyze 
    15  # statistics.
    16  #
    17  # Also include test cases for collating sequences on indices.
    18  #
    19  
    20  set testdir [file dirname $argv0]
    21  source $testdir/tester.tcl
    22  
    23  # If SQLITE_OMIT_ALTERTABLE is defined, omit this file.
    24  ifcapable !altertable {
    25    finish_test
    26    return
    27  }
    28  
    29  do_test analyze4-1.0 {
    30    db eval {
    31      CREATE TABLE t1(a,b);
    32      CREATE INDEX t1a ON t1(a);
    33      CREATE INDEX t1b ON t1(b);
    34      INSERT INTO t1 VALUES(1,NULL);
    35      INSERT INTO t1 SELECT a+1, b FROM t1;
    36      INSERT INTO t1 SELECT a+2, b FROM t1;
    37      INSERT INTO t1 SELECT a+4, b FROM t1;
    38      INSERT INTO t1 SELECT a+8, b FROM t1;
    39      INSERT INTO t1 SELECT a+16, b FROM t1;
    40      INSERT INTO t1 SELECT a+32, b FROM t1;
    41      INSERT INTO t1 SELECT a+64, b FROM t1;
    42      ANALYZE;
    43    }
    44  
    45    # Should choose the t1a index since it is more specific than t1b.
    46    db eval {EXPLAIN QUERY PLAN SELECT * FROM t1 WHERE a=5 AND b IS NULL}
    47  } {/*SEARCH t1 USING INDEX t1a (a=?)*/}
    48  
    49  # Verify that the t1b index shows that it does not narrow down the
    50  # search any at all.
    51  #
    52  do_test analyze4-1.1 {
    53    db eval {
    54      SELECT idx, stat FROM sqlite_stat1 WHERE tbl='t1' ORDER BY idx;
    55    }
    56  } {t1a {128 1} t1b {128 128}}
    57  
    58  # Change half of the b values from NULL to a constant.  Verify
    59  # that the number of rows selected in stat1 is half the total 
    60  # number of rows.
    61  #
    62  do_test analyze4-1.2 {
    63    db eval {
    64      UPDATE t1 SET b='x' WHERE a%2;
    65      ANALYZE;
    66      SELECT idx, stat FROM sqlite_stat1 WHERE tbl='t1' ORDER BY idx;
    67    }
    68  } {t1a {128 1} t1b {128 64}}
    69  
    70  # Change the t1.b values all back to NULL.  Add columns t1.c and t1.d.
    71  # Create a multi-column indices using t1.b and verify that ANALYZE 
    72  # processes them correctly.
    73  #
    74  do_test analyze4-1.3 {
    75    db eval {
    76      UPDATE t1 SET b=NULL;
    77      ALTER TABLE t1 ADD COLUMN c;
    78      ALTER TABLE t1 ADD COLUMN d;
    79      UPDATE t1 SET c=a/4, d=a/2;
    80      CREATE INDEX t1bcd ON t1(b,c,d);
    81      CREATE INDEX t1cdb ON t1(c,d,b);
    82      CREATE INDEX t1cbd ON t1(c,b,d);
    83      ANALYZE;
    84      SELECT idx, stat FROM sqlite_stat1 WHERE tbl='t1' ORDER BY idx;
    85    }
    86  } {t1a {128 1} t1b {128 128} t1bcd {128 128 4 2} t1cbd {128 4 4 2} t1cdb {128 4 2 2}}
    87  
    88  # Verify that collating sequences are taken into account when computing
    89  # ANALYZE statistics.
    90  #
    91  do_test analyze4-2.0 {
    92    db eval {
    93      CREATE TABLE t2(
    94        x INTEGER PRIMARY KEY,
    95        a TEXT COLLATE nocase,
    96        b TEXT COLLATE rtrim,
    97        c TEXT COLLATE binary
    98      );
    99      CREATE INDEX t2a ON t2(a);
   100      CREATE INDEX t2b ON t2(b);
   101      CREATE INDEX t2c ON t2(c);
   102      CREATE INDEX t2c2 ON t2(c COLLATE nocase);
   103      CREATE INDEX t2c3 ON t2(c COLLATE rtrim);
   104      INSERT INTO t2 VALUES(1, 'abc', 'abc', 'abc');
   105      INSERT INTO t2 VALUES(2, 'abC', 'abC', 'abC');
   106      INSERT INTO t2 VALUES(3, 'abc ', 'abc ', 'abc ');
   107      INSERT INTO t2 VALUES(4, 'abC ', 'abC ', 'abC ');
   108      INSERT INTO t2 VALUES(5, 'aBc', 'aBc', 'aBc');
   109      INSERT INTO t2 VALUES(6, 'aBC', 'aBC', 'aBC');
   110      INSERT INTO t2 VALUES(7, 'aBc ', 'aBc ', 'aBc ');
   111      INSERT INTO t2 VALUES(8, 'aBC ', 'aBC ', 'aBC ');
   112      ANALYZE;
   113      SELECT idx, stat FROM sqlite_stat1 WHERE tbl='t2' ORDER BY idx;
   114    }
   115  } {t2a {8 4} t2b {8 2} t2c {8 1} t2c2 {8 4} t2c3 {8 2}}
   116  
   117  finish_test