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45e2544584
composite type capability makes it possible to create a system view
based on a table function in a way that is hopefully palatable to
everyone. The attached patch takes advantage of this, moving
show_all_settings() from contrib/tablefunc into the backend (renamed
all_settings(). It is defined as a builtin returning type RECORD. During
initdb a system view is created to expose the same information presently
available through SHOW ALL. For example:
test=# select * from pg_settings where name like '%debug%';
name | setting
-----------------------+---------
debug_assertions | on
debug_pretty_print | off
debug_print_parse | off
debug_print_plan | off
debug_print_query | off
debug_print_rewritten | off
wal_debug | 0
(7 rows)
Additionally during initdb two rules are created which make it possible
to change settings by updating the system view -- a "virtual table" as
Tom put it. Here's an example:
Joe Conway
50 lines
3.6 KiB
SQL
50 lines
3.6 KiB
SQL
--
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-- show_all_settings()
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--
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SELECT * FROM show_all_settings();
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--
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-- normal_rand()
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--
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SELECT * FROM normal_rand(100, 250, 5, EXTRACT(SECONDS FROM CURRENT_TIME(0))::int);
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--
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-- crosstab()
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--
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create table ct(id serial, rowclass text, rowid text, attribute text, value text);
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insert into ct(rowclass, rowid, attribute, value) values('group1','test1','att1','val1');
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insert into ct(rowclass, rowid, attribute, value) values('group1','test1','att2','val2');
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insert into ct(rowclass, rowid, attribute, value) values('group1','test1','att3','val3');
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insert into ct(rowclass, rowid, attribute, value) values('group1','test1','att4','val4');
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insert into ct(rowclass, rowid, attribute, value) values('group1','test2','att1','val5');
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insert into ct(rowclass, rowid, attribute, value) values('group1','test2','att2','val6');
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insert into ct(rowclass, rowid, attribute, value) values('group1','test2','att3','val7');
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insert into ct(rowclass, rowid, attribute, value) values('group1','test2','att4','val8');
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insert into ct(rowclass, rowid, attribute, value) values('group2','test3','att1','val1');
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insert into ct(rowclass, rowid, attribute, value) values('group2','test3','att2','val2');
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insert into ct(rowclass, rowid, attribute, value) values('group2','test3','att3','val3');
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insert into ct(rowclass, rowid, attribute, value) values('group2','test4','att1','val4');
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insert into ct(rowclass, rowid, attribute, value) values('group2','test4','att2','val5');
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insert into ct(rowclass, rowid, attribute, value) values('group2','test4','att3','val6');
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select * from crosstab2('select rowid, attribute, value from ct where rowclass = ''group1'' and (attribute = ''att2'' or attribute = ''att3'') order by 1,2;');
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select * from crosstab3('select rowid, attribute, value from ct where rowclass = ''group1'' and (attribute = ''att2'' or attribute = ''att3'') order by 1,2;');
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select * from crosstab4('select rowid, attribute, value from ct where rowclass = ''group1'' and (attribute = ''att2'' or attribute = ''att3'') order by 1,2;');
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select * from crosstab2('select rowid, attribute, value from ct where rowclass = ''group1'' order by 1,2;');
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select * from crosstab3('select rowid, attribute, value from ct where rowclass = ''group1'' order by 1,2;');
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select * from crosstab4('select rowid, attribute, value from ct where rowclass = ''group1'' order by 1,2;');
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select * from crosstab2('select rowid, attribute, value from ct where rowclass = ''group2'' and (attribute = ''att1'' or attribute = ''att2'') order by 1,2;');
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select * from crosstab3('select rowid, attribute, value from ct where rowclass = ''group2'' and (attribute = ''att1'' or attribute = ''att2'') order by 1,2;');
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select * from crosstab4('select rowid, attribute, value from ct where rowclass = ''group2'' and (attribute = ''att1'' or attribute = ''att2'') order by 1,2;');
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select * from crosstab2('select rowid, attribute, value from ct where rowclass = ''group2'' order by 1,2;');
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select * from crosstab3('select rowid, attribute, value from ct where rowclass = ''group2'' order by 1,2;');
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select * from crosstab4('select rowid, attribute, value from ct where rowclass = ''group2'' order by 1,2;');
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select * from crosstab('select rowid, attribute, value from ct where rowclass = ''group1'' order by 1,2;', 2) as c(rowid text, att1 text, att2 text);
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select * from crosstab('select rowid, attribute, value from ct where rowclass = ''group1'' order by 1,2;', 3) as c(rowid text, att1 text, att2 text, att3 text);
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select * from crosstab('select rowid, attribute, value from ct where rowclass = ''group1'' order by 1,2;', 4) as c(rowid text, att1 text, att2 text, att3 text, att4 text);
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