Merlin Moncure wrote: > yeah, probably. Having said that, I'm really struggling that it can > take take several minutes to sort such a small number of rows even > with location issues. I can sort rocks faster than that :-). > > Switching between various european collations, I'm seeing subsecond > sort responses for 44k records on my test box. I don't have the laos > collation installed unfortunately. Are you seeing kind of penalty in > other conversions? I find that it makes a lot of difference what you sort: CREATE TABLE sort(t text); INSERT INTO sort SELECT 'ຕົວອັກສອນລາວ... ງ່າຍຂື້ນ' || i FROM generate_series(1, 100000) AS i; SET work_mem = '1GB'; EXPLAIN (ANALYZE, BUFFERS) SELECT t FROM sort ORDER BY t COLLATE "C"; [...] Execution Time: 288.752 ms EXPLAIN (ANALYZE, BUFFERS) SELECT t FROM sort ORDER BY t COLLATE "lo_LA.utf8"; [...] Execution Time: 47006.683 ms EXPLAIN (ANALYZE, BUFFERS) SELECT t FROM sort ORDER BY t COLLATE "en_US.utf8"; [...] Execution Time: 73962.934 ms CREATE TABLE sort2(t text); INSERT INTO sort2 SELECT 'this is plain old English' || i FROM generate_series(1, 100000) AS i; SET work_mem = '1GB'; EXPLAIN (ANALYZE, BUFFERS) SELECT t FROM sort2 ORDER BY t COLLATE "C"; [...] Execution Time: 237.615 ms EXPLAIN (ANALYZE, BUFFERS) SELECT t FROM sort2 ORDER BY t COLLATE "lo_LA.utf8"; [...] Execution Time: 2467.848 ms EXPLAIN (ANALYZE, BUFFERS) SELECT t FROM sort2 ORDER BY t COLLATE "en_US.utf8"; [...] Execution Time: 2927.667 ms This is on my x86_64 Fedora 29 system, kernel 4.20.6, glibc 2.28. Yours, Laurenz Albe -- Cybertec | https://www.cybertec-postgresql.com
