223 lines
3.4 KiB
Plaintext
223 lines
3.4 KiB
Plaintext
--
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-- SELECT_DISTINCT
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--
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--
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-- awk '{print $3;}' onek.data | sort -n | uniq
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--
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SELECT DISTINCT two FROM tmp ORDER BY 1;
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two
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-----
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0
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1
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(2 rows)
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--
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-- awk '{print $5;}' onek.data | sort -n | uniq
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--
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SELECT DISTINCT ten FROM tmp ORDER BY 1;
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ten
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-----
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0
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1
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2
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3
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4
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5
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6
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7
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8
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9
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(10 rows)
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--
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-- awk '{print $16;}' onek.data | sort -d | uniq
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--
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SELECT DISTINCT string4 FROM tmp ORDER BY 1;
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string4
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---------
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AAAAxx
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HHHHxx
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OOOOxx
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VVVVxx
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(4 rows)
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--
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-- awk '{print $3,$16,$5;}' onek.data | sort -d | uniq |
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-- sort +0n -1 +1d -2 +2n -3
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--
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SELECT DISTINCT two, string4, ten
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FROM tmp
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ORDER BY two using <, string4 using <, ten using <;
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two | string4 | ten
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-----+---------+-----
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0 | AAAAxx | 0
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0 | AAAAxx | 2
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0 | AAAAxx | 4
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0 | AAAAxx | 6
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0 | AAAAxx | 8
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0 | HHHHxx | 0
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0 | HHHHxx | 2
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0 | HHHHxx | 4
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0 | HHHHxx | 6
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0 | HHHHxx | 8
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0 | OOOOxx | 0
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0 | OOOOxx | 2
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0 | OOOOxx | 4
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0 | OOOOxx | 6
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0 | OOOOxx | 8
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0 | VVVVxx | 0
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0 | VVVVxx | 2
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0 | VVVVxx | 4
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0 | VVVVxx | 6
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0 | VVVVxx | 8
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1 | AAAAxx | 1
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1 | AAAAxx | 3
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1 | AAAAxx | 5
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1 | AAAAxx | 7
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1 | AAAAxx | 9
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1 | HHHHxx | 1
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1 | HHHHxx | 3
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1 | HHHHxx | 5
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1 | HHHHxx | 7
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1 | HHHHxx | 9
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1 | OOOOxx | 1
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1 | OOOOxx | 3
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1 | OOOOxx | 5
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1 | OOOOxx | 7
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1 | OOOOxx | 9
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1 | VVVVxx | 1
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1 | VVVVxx | 3
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1 | VVVVxx | 5
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1 | VVVVxx | 7
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1 | VVVVxx | 9
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(40 rows)
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--
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-- awk '{print $2;}' person.data |
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-- awk '{if(NF!=1){print $2;}else{print;}}' - emp.data |
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-- awk '{if(NF!=1){print $2;}else{print;}}' - student.data |
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-- awk 'BEGIN{FS=" ";}{if(NF!=1){print $5;}else{print;}}' - stud_emp.data |
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-- sort -n -r | uniq
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--
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SELECT DISTINCT p.age FROM person* p ORDER BY age using >;
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age
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-----
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98
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88
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78
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68
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60
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58
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50
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48
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40
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38
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34
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30
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28
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25
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24
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23
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20
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19
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18
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8
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(20 rows)
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--
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-- Also, some tests of IS DISTINCT FROM, which doesn't quite deserve its
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-- very own regression file.
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--
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CREATE TEMP TABLE disttable (f1 integer);
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INSERT INTO DISTTABLE VALUES(1);
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INSERT INTO DISTTABLE VALUES(2);
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INSERT INTO DISTTABLE VALUES(3);
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INSERT INTO DISTTABLE VALUES(NULL);
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-- basic cases
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SELECT f1, f1 IS DISTINCT FROM 2 as "not 2" FROM disttable;
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f1 | not 2
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----+-------
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1 | t
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2 | f
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3 | t
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| t
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(4 rows)
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SELECT f1, f1 IS DISTINCT FROM NULL as "not null" FROM disttable;
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f1 | not null
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----+----------
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1 | t
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2 | t
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3 | t
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| f
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(4 rows)
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SELECT f1, f1 IS DISTINCT FROM f1 as "false" FROM disttable;
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f1 | false
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----+-------
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1 | f
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2 | f
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3 | f
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| f
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(4 rows)
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SELECT f1, f1 IS DISTINCT FROM f1+1 as "not null" FROM disttable;
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f1 | not null
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----+----------
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1 | t
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2 | t
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3 | t
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| f
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(4 rows)
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-- check that optimizer constant-folds it properly
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SELECT 1 IS DISTINCT FROM 2 as "yes";
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yes
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-----
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t
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(1 row)
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SELECT 2 IS DISTINCT FROM 2 as "no";
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no
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----
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f
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(1 row)
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SELECT 2 IS DISTINCT FROM null as "yes";
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yes
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-----
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t
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(1 row)
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SELECT null IS DISTINCT FROM null as "no";
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no
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----
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f
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(1 row)
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-- negated form
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SELECT 1 IS NOT DISTINCT FROM 2 as "no";
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no
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----
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f
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(1 row)
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SELECT 2 IS NOT DISTINCT FROM 2 as "yes";
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yes
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-----
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t
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(1 row)
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SELECT 2 IS NOT DISTINCT FROM null as "no";
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no
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----
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f
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(1 row)
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SELECT null IS NOT DISTINCT FROM null as "yes";
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yes
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-----
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t
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(1 row)
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