mirror of
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298 lines
9.0 KiB
Plaintext
298 lines
9.0 KiB
Plaintext
--
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-- FLOAT8
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--
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CREATE TABLE FLOAT8_TBL(f1 float8);
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INSERT INTO FLOAT8_TBL(f1) VALUES ('0.0');
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INSERT INTO FLOAT8_TBL(f1) VALUES ('1004.30');
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INSERT INTO FLOAT8_TBL(f1) VALUES ('-34.84');
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INSERT INTO FLOAT8_TBL(f1) VALUES ('1.2345678901234e+200');
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INSERT INTO FLOAT8_TBL(f1) VALUES ('1.2345678901234e-200');
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SELECT '' AS five, FLOAT8_TBL.*;
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five | f1
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------+----------------------
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| 0
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| 1004.3
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| -34.84
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| 1.2345678901234e+200
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| 1.2345678901234e-200
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(5 rows)
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SELECT '' AS four, f.* FROM FLOAT8_TBL f WHERE f.f1 <> '1004.3';
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four | f1
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------+----------------------
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| 0
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| -34.84
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| 1.2345678901234e+200
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| 1.2345678901234e-200
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(4 rows)
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SELECT '' AS one, f.* FROM FLOAT8_TBL f WHERE f.f1 = '1004.3';
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one | f1
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-----+--------
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| 1004.3
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(1 row)
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SELECT '' AS three, f.* FROM FLOAT8_TBL f WHERE '1004.3' > f.f1;
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three | f1
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-------+----------------------
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| 0
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| -34.84
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| 1.2345678901234e-200
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(3 rows)
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SELECT '' AS three, f.* FROM FLOAT8_TBL f WHERE f.f1 < '1004.3';
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three | f1
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-------+----------------------
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| 0
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| -34.84
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| 1.2345678901234e-200
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(3 rows)
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SELECT '' AS four, f.* FROM FLOAT8_TBL f WHERE '1004.3' >= f.f1;
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four | f1
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------+----------------------
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| 0
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| 1004.3
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| -34.84
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| 1.2345678901234e-200
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(4 rows)
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SELECT '' AS four, f.* FROM FLOAT8_TBL f WHERE f.f1 <= '1004.3';
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four | f1
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------+----------------------
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| 0
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| 1004.3
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| -34.84
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| 1.2345678901234e-200
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(4 rows)
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SELECT '' AS three, f.f1, f.f1 * '-10' AS x
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FROM FLOAT8_TBL f
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WHERE f.f1 > '0.0';
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three | f1 | x
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-------+----------------------+-----------------------
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| 1004.3 | -10043
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| 1.2345678901234e+200 | -1.2345678901234e+201
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| 1.2345678901234e-200 | -1.2345678901234e-199
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(3 rows)
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SELECT '' AS three, f.f1, f.f1 + '-10' AS x
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FROM FLOAT8_TBL f
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WHERE f.f1 > '0.0';
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three | f1 | x
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-------+----------------------+----------------------
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| 1004.3 | 994.3
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| 1.2345678901234e+200 | 1.2345678901234e+200
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| 1.2345678901234e-200 | -10
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(3 rows)
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SELECT '' AS three, f.f1, f.f1 / '-10' AS x
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FROM FLOAT8_TBL f
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WHERE f.f1 > '0.0';
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three | f1 | x
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-------+----------------------+-----------------------
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| 1004.3 | -100.43
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| 1.2345678901234e+200 | -1.2345678901234e+199
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| 1.2345678901234e-200 | -1.2345678901234e-201
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(3 rows)
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SELECT '' AS three, f.f1, f.f1 - '-10' AS x
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FROM FLOAT8_TBL f
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WHERE f.f1 > '0.0';
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three | f1 | x
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-------+----------------------+----------------------
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| 1004.3 | 1014.3
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| 1.2345678901234e+200 | 1.2345678901234e+200
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| 1.2345678901234e-200 | 10
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(3 rows)
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SELECT '' AS one, f.f1 ^ '2.0' AS square_f1
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FROM FLOAT8_TBL f where f.f1 = '1004.3';
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one | square_f1
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-----+------------
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| 1008618.49
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(1 row)
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-- absolute value
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SELECT '' AS five, f.f1, @f.f1 AS abs_f1
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FROM FLOAT8_TBL f;
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five | f1 | abs_f1
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------+----------------------+----------------------
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| 0 | 0
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| 1004.3 | 1004.3
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| -34.84 | 34.84
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| 1.2345678901234e+200 | 1.2345678901234e+200
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| 1.2345678901234e-200 | 1.2345678901234e-200
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(5 rows)
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-- truncate
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SELECT '' AS five, f.f1, %f.f1 AS trunc_f1
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FROM FLOAT8_TBL f;
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five | f1 | trunc_f1
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------+----------------------+----------------------
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| 0 | 0
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| 1004.3 | 1004
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| -34.84 | -34
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| 1.2345678901234e+200 | 1.2345678901234e+200
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| 1.2345678901234e-200 | 0
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(5 rows)
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-- round
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SELECT '' AS five, f.f1, f.f1 % AS round_f1
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FROM FLOAT8_TBL f;
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five | f1 | round_f1
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------+----------------------+----------------------
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| 0 | 0
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| 1004.3 | 1004
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| -34.84 | -35
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| 1.2345678901234e+200 | 1.2345678901234e+200
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| 1.2345678901234e-200 | 0
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(5 rows)
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-- ceil
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select ceil(f1) as ceil_f1 from float8_tbl f;
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ceil_f1
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----------------------
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0
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1005
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-34
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1.2345678901234e+200
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1
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(5 rows)
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-- floor
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select floor(f1) as floor_f1 from float8_tbl f;
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floor_f1
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----------------------
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0
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1004
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-35
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1.2345678901234e+200
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0
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(5 rows)
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-- sign
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select sign(f1) as sign_f1 from float8_tbl f;
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sign_f1
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---------
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0
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1
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-1
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1
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1
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(5 rows)
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-- square root
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SELECT sqrt(float8 '64') AS eight;
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eight
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-------
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8
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(1 row)
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SELECT |/ float8 '64' AS eight;
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eight
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-------
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8
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(1 row)
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SELECT '' AS three, f.f1, |/f.f1 AS sqrt_f1
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FROM FLOAT8_TBL f
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WHERE f.f1 > '0.0';
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three | f1 | sqrt_f1
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-------+----------------------+-----------------------
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| 1004.3 | 31.6906926399535
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| 1.2345678901234e+200 | 1.11111110611109e+100
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| 1.2345678901234e-200 | 1.11111110611109e-100
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(3 rows)
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-- take exp of ln(f.f1)
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SELECT '' AS three, f.f1, exp(ln(f.f1)) AS exp_ln_f1
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FROM FLOAT8_TBL f
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WHERE f.f1 > '0.0';
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three | f1 | exp_ln_f1
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-------+----------------------+-----------------------
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| 1004.3 | 1004.3
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| 1.2345678901234e+200 | 1.23456789012338e+200
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| 1.2345678901234e-200 | 1.23456789012339e-200
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(3 rows)
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-- cube root
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SELECT ||/ float8 '27' AS three;
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three
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-------
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3
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(1 row)
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SELECT '' AS five, f.f1, ||/f.f1 AS cbrt_f1 FROM FLOAT8_TBL f;
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five | f1 | cbrt_f1
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------+----------------------+----------------------
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| 0 | 0
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| 1004.3 | 10.014312837827
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| -34.84 | -3.26607421344208
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| 1.2345678901234e+200 | 4.97933859234765e+66
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| 1.2345678901234e-200 | 2.3112042409018e-67
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(5 rows)
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SELECT '' AS five, FLOAT8_TBL.*;
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five | f1
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------+----------------------
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| 0
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| 1004.3
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| -34.84
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| 1.2345678901234e+200
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| 1.2345678901234e-200
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(5 rows)
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UPDATE FLOAT8_TBL
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SET f1 = FLOAT8_TBL.f1 * '-1'
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WHERE FLOAT8_TBL.f1 > '0.0';
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SELECT '' AS bad, f.f1 * '1e200' from FLOAT8_TBL f;
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ERROR: floating point exception! The last floating point operation either exceeded legal ranges or was a divide by zero
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SELECT '' AS bad, f.f1 ^ '1e200' from FLOAT8_TBL f;
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ERROR: pow() result is out of range
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SELECT '' AS bad, ln(f.f1) from FLOAT8_TBL f where f.f1 = '0.0' ;
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ERROR: can't take log of zero
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SELECT '' AS bad, ln(f.f1) from FLOAT8_TBL f where f.f1 < '0.0' ;
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ERROR: can't take log of a negative number
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SELECT '' AS bad, exp(f.f1) from FLOAT8_TBL f;
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ERROR: exp() result is out of range
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SELECT '' AS bad, f.f1 / '0.0' from FLOAT8_TBL f;
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ERROR: float8div: divide by zero error
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SELECT '' AS five, FLOAT8_TBL.*;
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five | f1
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------+-----------------------
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| 0
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| -34.84
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| -1004.3
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| -1.2345678901234e+200
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| -1.2345678901234e-200
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(5 rows)
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-- test for over- and underflow
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INSERT INTO FLOAT8_TBL(f1) VALUES ('10e400');
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ERROR: Input '10e400' is out of range for float8
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INSERT INTO FLOAT8_TBL(f1) VALUES ('-10e400');
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ERROR: Input '-10e400' is out of range for float8
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INSERT INTO FLOAT8_TBL(f1) VALUES ('10e-400');
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ERROR: Input '10e-400' is out of range for float8
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INSERT INTO FLOAT8_TBL(f1) VALUES ('-10e-400');
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ERROR: Input '-10e-400' is out of range for float8
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-- maintain external table consistency across platforms
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-- delete all values and reinsert well-behaved ones
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DELETE FROM FLOAT8_TBL;
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INSERT INTO FLOAT8_TBL(f1) VALUES ('0.0');
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INSERT INTO FLOAT8_TBL(f1) VALUES ('-34.84');
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INSERT INTO FLOAT8_TBL(f1) VALUES ('-1004.30');
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INSERT INTO FLOAT8_TBL(f1) VALUES ('-1.2345678901234e+200');
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INSERT INTO FLOAT8_TBL(f1) VALUES ('-1.2345678901234e-200');
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SELECT '' AS five, FLOAT8_TBL.*;
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five | f1
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------+-----------------------
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| 0
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| -34.84
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| -1004.3
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| -1.2345678901234e+200
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| -1.2345678901234e-200
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(5 rows)
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