github.com/matrixorigin/matrixone@v1.2.0/test/distributed/cases/function/func_math_log2.result (about)

     1  select log2(log2(256)),log2(log2(2));
     2  log2(log2(256))    log2(log2(2))
     3  3.0    0.0
     4  SELECT log2(1024);
     5  log2(1024)
     6  10.0
     7  SELECT log2(-1024);
     8  invalid argument log2, bad value -1024
     9  SELECT log2(0);
    10  invalid argument log2, bad value 0
    11  select log2(0.00000000000000001);
    12  log2(0.00000000000000001)
    13  -56.47277761308516
    14  select log2(2e2);
    15  log2(2e2)
    16  7.643856189774724
    17  select log2(0.141241241241313);
    18  log2(0.141241241241313)
    19  -2.8237666900817837
    20  select log2(-124314124124.12412341);
    21  invalid argument log2, bad value -1.2431412412412413e+11
    22  select log2(null);
    23  log2(null)
    24  null
    25  CREATE TABLE t1(a DOUBLE);
    26  INSERT INTO t1 select (log2(56));
    27  INSERT INTO t1 select (log2(100));
    28  SELECT * FROM t1 ORDER BY a;
    29  a
    30  5.807354922057604
    31  6.643856189774724
    32  drop table t1;
    33  create table t1(a tinyint, b SMALLINT, c bigint, d INT, e BIGINT, f FLOAT, g DOUBLE, h decimal(38,19));
    34  insert into t1 values(1, 1, 2, 4, 5, 5.5, 31.13, 14.314);
    35  select log2(a),log2(b),log2(c),log2(d),log2(e),log2(f),log2(g),log2(h) from t1;
    36  log2(a)    log2(b)    log2(c)    log2(d)    log2(e)    log2(f)    log2(g)    log2(h)
    37  0.0    0.0    1.0    2.0    2.321928094887362    2.4594316186372973    4.960233671694454    3.8393549796546487
    38  drop table t1;
    39  select log2(123.54-123.03);
    40  log2(123.54 - 123.03)
    41  -0.9714308478032292
    42  select log2(123.54*0.34);
    43  log2(123.54 * 0.34)
    44  5.3924410770543005
    45  select log2(134)-log2(194);
    46  log2(134) - log2(194)
    47  -0.5338236517293549
    48  drop table if exists t1;
    49  create table t1(a int);
    50  insert into t1 values(10), (100);
    51  select distinct * from t1 where log2(a)>0;
    52  a
    53  10
    54  100
    55  drop table t1;
    56  create table t1(a INT, b int);
    57  create table t2(a INT, b int);
    58  insert into t1 values(2,4), (100,23);
    59  insert into t2 values(10,100), (4,41);
    60  SELECT t1.a, t2.a FROM t1 JOIN t2 ON (log2(t1.a) <> log2(t2.a));
    61  a    a
    62  2    10
    63  2    4
    64  100    10
    65  100    4
    66  drop table t1;
    67  drop table t2;
    68  drop table if exists t1;
    69  create table t1(a float,  b float);
    70  insert into t1 values(14.413, 43.413), (8.123, 0.409);
    71  select b from t1 group by b having log2(b)>0;
    72  b
    73  43.413
    74  drop table t1;