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|
-- window functions
CREATE FUNCTION js_row_number() RETURNS numeric AS $$
var winobj = pljs.get_window_object();
return winobj.get_current_position() + 1;
$$ LANGUAGE pljs WINDOW;
CREATE FUNCTION __js_rank_up(winobj internal, up_callback internal) RETURNS void AS $$
var context = winobj.get_partition_local() || {};
var pos = winobj.get_current_position();
context.up = false;
if (!context.rank) {
context.rank = 1;
} else {
if (!winobj.rows_are_peers(pos, pos - 1)) {
context.up = true;
if (up_callback) {
up_callback(context);
}
}
}
winobj.set_mark_position(pos);
winobj.set_partition_local(context);
return context;
$$ LANGUAGE pljs;
CREATE FUNCTION js_rank() RETURNS numeric AS $$
var winobj = pljs.get_window_object();
var context = pljs.find_function("__js_rank_up")(winobj, function(context){
context.rank = winobj.get_current_position() + 1;
});
return context.rank;
$$ LANGUAGE pljs WINDOW;
CREATE FUNCTION js_dense_rank() RETURNS numeric AS $$
var winobj = pljs.get_window_object();
var context = pljs.find_function("__js_rank_up")(winobj, function(context){
context.rank++;
});
return context.rank;
$$ LANGUAGE pljs WINDOW;
CREATE FUNCTION js_percent_rank() RETURNS float AS $$
var winobj = pljs.get_window_object();
var totalrows = winobj.get_partition_row_count();
if (totalrows <= 1)
return 0.0;
var context = pljs.find_function("__js_rank_up")(winobj, function(context){
context.rank = winobj.get_current_position() + 1;
});
return (context.rank - 1) / (totalrows - 1);
$$ LANGUAGE pljs WINDOW;
CREATE FUNCTION js_cume_dist() RETURNS float AS $$
var winobj = pljs.get_window_object();
var totalrows = winobj.get_partition_row_count();
var context = pljs.find_function("__js_rank_up")(winobj);
if (context.up || context.rank == 1) {
context.rank = winobj.get_current_position() + 1;
for (var row = context.rank; row < totalrows; row++) {
if (!winobj.rows_are_peers(row - 1, row)) {
break;
}
context.rank++;
}
}
winobj.set_partition_local(context);
return context.rank / totalrows;
$$ LANGUAGE pljs WINDOW;
CREATE FUNCTION js_ntile(nbuckets numeric) RETURNS int AS $$
var winobj = pljs.get_window_object();
var context = winobj.get_partition_local() || {};
if (!context.ntile) {
context.rows_per_bucket = 0;
var total = winobj.get_partition_row_count();
var nbuckets = winobj.get_func_arg_current(0);
if (nbuckets === null) {
return null;
}
if (nbuckets <= 0) {
pljs.elog(ERROR, "argument of ntile must be greater than zero");
}
context.ntile = 1;
context.rows_per_bucket = 0;
context.boundary = total / nbuckets;
if (context.boundary <= 0) {
context.boundary = 1;
} else {
context.remainder = total % nbuckets;
if (context.remainder != 0) {
context.boundary++;
}
}
}
context.rows_per_bucket++;
if (context.boundary < context.rows_per_bucket) {
if (context.remainder != 0 && context.ntile == context.remainder) {
context.remainder = 0;
context.boundary -= 1;
}
context.ntile += 1;
context.rows_per_bucket = 1;
}
winobj.set_partition_local(context);
return context.ntile;
$$ LANGUAGE pljs WINDOW;
CREATE FUNCTION __js_lead_lag_common(forward internal, withoffset internal, withdefault internal) RETURNS text AS $$
var winobj = pljs.get_window_object();
var offset;
if (withoffset) {
offset = winobj.get_func_arg_current(1);
if (offset === null) {
return null;
}
} else {
offset = 1;
}
var result = winobj.get_func_arg_in_partition(0,
forward ? offset : -offset,
winobj.SEEK_CURRENT,
false);
if (result === undefined) {
if (withdefault) {
result = winobj.get_func_arg_current(2);
}
}
if (result === null) {
return null;
}
return result;
$$ LANGUAGE pljs;
CREATE FUNCTION js_lag(arg anyelement) RETURNS anyelement AS $$
return pljs.find_function("__js_lead_lag_common")(false, false, false);
$$ LANGUAGE pljs WINDOW;
CREATE FUNCTION js_lag(arg anyelement, ofs int) RETURNS anyelement AS $$
return pljs.find_function("__js_lead_lag_common")(false, true, false);
$$ LANGUAGE pljs WINDOW;
CREATE FUNCTION js_lag(arg anyelement, ofs int, deflt anyelement) RETURNS anyelement AS $$
return pljs.find_function("__js_lead_lag_common")(false, true, true);
$$ LANGUAGE pljs WINDOW;
CREATE FUNCTION js_lead(arg anyelement) RETURNS anyelement AS $$
return pljs.find_function("__js_lead_lag_common")(true, false, false);
$$ LANGUAGE pljs WINDOW;
CREATE FUNCTION js_lead(arg anyelement, ofs int) RETURNS anyelement AS $$
return pljs.find_function("__js_lead_lag_common")(true, true, false);
$$ LANGUAGE pljs WINDOW;
CREATE FUNCTION js_lead(arg anyelement, ofs int, deflt anyelement) RETURNS anyelement AS $$
return pljs.find_function("__js_lead_lag_common")(true, true, true);
$$ LANGUAGE pljs WINDOW;
CREATE FUNCTION js_first_value(arg anyelement) RETURNS anyelement AS $$
var winobj = pljs.get_window_object();
return winobj.get_func_arg_in_frame(0, 0, winobj.SEEK_HEAD, true);
$$ LANGUAGE pljs WINDOW;
CREATE FUNCTION js_last_value(arg anyelement) RETURNS anyelement AS $$
var winobj = pljs.get_window_object();
return winobj.get_func_arg_in_frame(0, 0, winobj.SEEK_TAIL, true);
$$ LANGUAGE pljs WINDOW;
CREATE FUNCTION js_nth_value(arg anyelement, nth int) RETURNS anyelement AS $$
var winobj = pljs.get_window_object();
nth = winobj.get_func_arg_current(1);
if (nth <= 0)
pljs.elog(ERROR, "argument of nth_value must be greater than zero");
return winobj.get_func_arg_in_frame(0, nth - 1, winobj.SEEK_HEAD, false);
$$ LANGUAGE pljs WINDOW;
CREATE TABLE empsalary (
depname varchar,
empno bigint,
salary int,
enroll_date date
);
INSERT INTO empsalary VALUES
('develop', 10, 5200, '2007-08-01'),
('sales', 1, 5000, '2006-10-01'),
('personnel', 5, 3500, '2007-12-10'),
('sales', 4, 4800, '2007-08-08'),
('personnel', 2, 3900, '2006-12-23'),
('develop', 7, 4200, '2008-01-01'),
('develop', 9, 4500, '2008-01-01'),
('sales', 3, 4800, '2007-08-01'),
('develop', 8, 6000, '2006-10-01'),
('develop', 11, 5200, '2007-08-15');
SELECT row_number() OVER (w), js_row_number() OVER (w) FROM empsalary WINDOW w AS (ORDER BY salary);
row_number | js_row_number
------------+---------------
1 | 1
2 | 2
3 | 3
4 | 4
5 | 5
6 | 6
7 | 7
8 | 8
9 | 9
10 | 10
(10 rows)
SELECT rank() OVER (w), js_rank() OVER (w) FROM empsalary WINDOW w AS (PARTITION BY depname ORDER BY salary);
rank | js_rank
------+---------
1 | 1
2 | 2
3 | 3
3 | 3
5 | 5
1 | 1
2 | 2
1 | 1
1 | 1
3 | 3
(10 rows)
SELECT dense_rank() OVER (w), js_dense_rank() OVER (w) FROM empsalary WINDOW w AS (ORDER BY salary);
dense_rank | js_dense_rank
------------+---------------
1 | 1
2 | 2
3 | 3
4 | 4
5 | 5
5 | 5
6 | 6
7 | 7
7 | 7
8 | 8
(10 rows)
SET extra_float_digits = 0;
SELECT percent_rank() OVER (w), js_percent_rank() OVER (w) FROM empsalary WINDOW w AS (ORDER BY salary);
percent_rank | js_percent_rank
-------------------+-------------------
0 | 0
0.111111111111111 | 0.111111111111111
0.222222222222222 | 0.222222222222222
0.333333333333333 | 0.333333333333333
0.444444444444444 | 0.444444444444444
0.444444444444444 | 0.444444444444444
0.666666666666667 | 0.666666666666667
0.777777777777778 | 0.777777777777778
0.777777777777778 | 0.777777777777778
1 | 1
(10 rows)
RESET extra_float_digits;
SELECT cume_dist() OVER (w), js_cume_dist() OVER (w) FROM empsalary WINDOW w AS (ORDER BY salary);
cume_dist | js_cume_dist
-----------+--------------
0.1 | 0.1
0.2 | 0.2
0.3 | 0.3
0.4 | 0.4
0.6 | 0.6
0.6 | 0.6
0.7 | 0.7
0.9 | 0.9
0.9 | 0.9
1 | 1
(10 rows)
SELECT ntile(3) OVER (w), js_ntile(3) OVER (w) FROM empsalary WINDOW w AS (ORDER BY salary);
ntile | js_ntile
-------+----------
1 | 1
1 | 1
1 | 1
1 | 1
2 | 2
2 | 2
2 | 2
3 | 3
3 | 3
3 | 3
(10 rows)
SELECT lag(enroll_date) OVER (w), js_lag(enroll_date) OVER (w) FROM empsalary WINDOW w AS (ORDER BY salary);
lag | js_lag
------------+------------
|
12-10-2007 | 12-10-2007
12-23-2006 | 12-23-2006
01-01-2008 | 01-01-2008
01-01-2008 | 01-01-2008
08-08-2007 | 08-08-2007
08-01-2007 | 08-01-2007
10-01-2006 | 10-01-2006
08-15-2007 | 08-15-2007
08-01-2007 | 08-01-2007
(10 rows)
SELECT lead(enroll_date) OVER (w), js_lead(enroll_date) OVER (w) FROM empsalary WINDOW w AS (ORDER BY salary);
lead | js_lead
------------+------------
12-23-2006 | 12-23-2006
01-01-2008 | 01-01-2008
01-01-2008 | 01-01-2008
08-08-2007 | 08-08-2007
08-01-2007 | 08-01-2007
10-01-2006 | 10-01-2006
08-15-2007 | 08-15-2007
08-01-2007 | 08-01-2007
10-01-2006 | 10-01-2006
|
(10 rows)
SELECT first_value(empno) OVER (w ROWS BETWEEN 2 PRECEDING AND 2 FOLLOWING),
js_first_value(empno) OVER (w ROWS BETWEEN 2 PRECEDING AND 2 FOLLOWING)
FROM empsalary WINDOW w AS (ORDER BY salary);
first_value | js_first_value
-------------+----------------
5 | 5
5 | 5
5 | 5
2 | 2
7 | 7
9 | 9
4 | 4
3 | 3
1 | 1
11 | 11
(10 rows)
SELECT last_value(empno) OVER (w ROWS BETWEEN 3 PRECEDING AND 1 PRECEDING),
js_last_value(empno) OVER (w ROWS BETWEEN 3 PRECEDING AND 1 PRECEDING)
FROM empsalary WINDOW w AS (ORDER BY salary);
last_value | js_last_value
------------+---------------
|
5 | 5
2 | 2
7 | 7
9 | 9
4 | 4
3 | 3
1 | 1
11 | 11
10 | 10
(10 rows)
SELECT nth_value(empno, 2) OVER (w ROWS BETWEEN 1 FOLLOWING AND 3 FOLLOWING),
js_nth_value(empno, 2) OVER (w ROWS BETWEEN 1 FOLLOWING AND 3 FOLLOWING)
FROM empsalary WINDOW w AS (ORDER BY salary);
nth_value | js_nth_value
-----------+--------------
7 | 7
9 | 9
4 | 4
3 | 3
1 | 1
11 | 11
10 | 10
8 | 8
|
|
(10 rows)
CREATE FUNCTION bad_alloc(sz text) RETURNS void AS $$
var winobj = pljs.get_window_object();
var context = winobj.get_partition_local(sz - 0) || {};
context.long_text_key_and_value = "blablablablablablablablablablablablablablablabla";
winobj.set_partition_local(context);
$$ LANGUAGE pljs WINDOW;
SELECT bad_alloc('5') OVER ();
ERROR: execution error
DETAIL: Error: window local memory overflow
at bad_alloc (<function>:6:29)
SELECT bad_alloc('not a number') OVER ();
bad_alloc
-----------
(1 row)
SELECT bad_alloc('1000') OVER (); -- not so bad
bad_alloc
-----------
(1 row)
CREATE FUNCTION non_window() RETURNS void AS $$
var winobj = pljs.get_window_object();
$$ LANGUAGE pljs;
SELECT non_window();
ERROR: execution error
DETAIL: Error: get_window_object called in wrong context
at non_window (<function>:3:38)
|
