2016-12-19 4:21 GMT+05:00 David Fetter <da...@fetter.org>:
> Couldn't it sleep in increments smaller than a second? Like maybe
> milliseconds? Also, it's probably cleaner (or at least more
> comprehensible) to write something using format() and dollar quoting
> than the line with the double 's.
Right. Here's version which waits for half a second. I do not see how
to path doubles via dollar sign, pg_background_launch() gets a string
as a parameter, it's not EXCEUTE USING.
Best regards, Andrey Borodin.
diff --git a/contrib/pg_background/Makefile b/contrib/pg_background/Makefile
index c4e717d..085fbff 100644
--- a/contrib/pg_background/Makefile
+++ b/contrib/pg_background/Makefile
@@ -6,6 +6,8 @@ OBJS = pg_background.o
EXTENSION = pg_background
DATA = pg_background--1.0.sql
+REGRESS = pg_background
+
ifdef USE_PGXS
PG_CONFIG = pg_config
PGXS := $(shell $(PG_CONFIG) --pgxs)
diff --git a/contrib/pg_background/expected/pg_background.out
b/contrib/pg_background/expected/pg_background.out
new file mode 100644
index 0000000..a6613ce
--- /dev/null
+++ b/contrib/pg_background/expected/pg_background.out
@@ -0,0 +1,31 @@
+CREATE EXTENSION pg_background;
+--run 6 workers which wait .0, .1, .2, .3, .4, .5 seconds respectively
+CREATE TABLE input as SELECT x FROM generate_series(0,.5,0.1) x ORDER BY x
DESC;
+CREATE TABLE output(place int,value float);
+--sequence for indication of who's finished on which place
+CREATE sequence s start 1;
+CREATE TABLE handles as SELECT pg_background_launch(format('select
pg_sleep(%s); insert into output values (nextval(''s''),%s);',x,x)) h FROM
input;
+--wait until everyone finishes
+SELECT (SELECT * FROM pg_background_result(h) as (x text) limit 1) FROM
handles;
+ x
+----------
+ SELECT 1
+ SELECT 1
+ SELECT 1
+ SELECT 1
+ SELECT 1
+ SELECT 1
+(6 rows)
+
+--output results
+SELECT * FROM output ORDER BY place;
+ place | value
+-------+-------
+ 1 | 0
+ 2 | 0.1
+ 3 | 0.2
+ 4 | 0.3
+ 5 | 0.4
+ 6 | 0.5
+(6 rows)
+
diff --git a/contrib/pg_background/sql/pg_background.sql
b/contrib/pg_background/sql/pg_background.sql
new file mode 100644
index 0000000..770f0b8
--- /dev/null
+++ b/contrib/pg_background/sql/pg_background.sql
@@ -0,0 +1,12 @@
+CREATE EXTENSION pg_background;
+
+--run 6 workers which wait .0, .1, .2, .3, .4, .5 seconds respectively
+CREATE TABLE input as SELECT x FROM generate_series(0,.5,0.1) x ORDER BY x
DESC;
+CREATE TABLE output(place int,value float);
+--sequence for indication of who's finished on which place
+CREATE sequence s start 1;
+CREATE TABLE handles as SELECT pg_background_launch(format('select
pg_sleep(%s); insert into output values (nextval(''s''),%s);',x,x)) h FROM
input;
+--wait until everyone finishes
+SELECT (SELECT * FROM pg_background_result(h) as (x text) limit 1) FROM
handles;
+--output results
+SELECT * FROM output ORDER BY place;
--
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers
