[server] Make connection pooler configurable and set better default values
Drop the configuration connections-pool-size and add new configurations options:
* connections-pool-min-size. Set to 0 by default so we open connections only
when needed. This avoid opening min-size*processes connections at startup,
which is, it think, a good default.
* connections-pool-max-size. Set to 0 (unlimited) by default, so we move the
bottleneck to postgresql.
* connections-idle-timeout. Set to 10 minutes. I don't have arguments about
this except that this is the default in pgbouncer.
/* -*- sql -*-
postgres specific registered procedures,
require the plpgsql language installed
*/
DROP FUNCTION IF EXISTS comma_join (anyarray) CASCADE;
CREATE FUNCTION comma_join (anyarray) RETURNS text AS $$
SELECT array_to_string($1, ', ')
$$ LANGUAGE SQL;;
DROP FUNCTION IF EXISTS cw_array_append_unique (anyarray, anyelement) CASCADE;
CREATE FUNCTION cw_array_append_unique (anyarray, anyelement) RETURNS anyarray AS $$
SELECT array_append($1, (SELECT $2 WHERE $2 <> ALL($1)))
$$ LANGUAGE SQL;;
DROP AGGREGATE IF EXISTS group_concat (anyelement) CASCADE;
CREATE AGGREGATE group_concat (
basetype = anyelement,
sfunc = cw_array_append_unique,
stype = anyarray,
finalfunc = comma_join,
initcond = '{}'
);;
DROP FUNCTION IF EXISTS limit_size (fulltext text, format text, maxsize integer);
CREATE FUNCTION limit_size (fulltext text, format text, maxsize integer) RETURNS text AS $$
DECLARE
plaintext text;
BEGIN
IF char_length(fulltext) < maxsize THEN
RETURN fulltext;
END IF;
IF format = 'text/html' OR format = 'text/xhtml' OR format = 'text/xml' THEN
plaintext := regexp_replace(fulltext, '<[a-zA-Z/][^>]*>', '', 'g');
ELSE
plaintext := fulltext;
END IF;
IF char_length(plaintext) < maxsize THEN
RETURN plaintext;
ELSE
RETURN substring(plaintext from 1 for maxsize) || '...';
END IF;
END
$$ LANGUAGE plpgsql;;
DROP FUNCTION IF EXISTS text_limit_size (fulltext text, maxsize integer);
CREATE FUNCTION text_limit_size (fulltext text, maxsize integer) RETURNS text AS $$
BEGIN
RETURN limit_size(fulltext, 'text/plain', maxsize);
END
$$ LANGUAGE plpgsql;;