[HACKERS] How strings are sorted by LC_COLLATE specifically?

Hello Dear All. How strings are sorted when LC_COLLATE = ja_JP.UTF-8. I tried to read the documention on that,but there are just a few words, like LC_COLLATE determines string sort order, Is there a specific reference about this? So I can implement an equivalent string sort function in JAVA. becau

Re: [HACKERS] [COMMITTERS] How strings are sorted by LC_COLLATE specifically?

Hi,Robert. Thanks for your reply. As far as I looked into postgre's source, I came to know that It seems that it uses strcoll to compare strings. So it depends on the underlying operating system,like you said. Charles. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To ma

[HACKERS] The rewritting of join conditions caused a very slow query plan.

Hi,all I have a query that is very slow,and the reason may be in the rewritting of join conditions. this is the simplied version table and the key part of the sql. level1_table and level2_table hold the tree data nodes, and all_level_status table holds the current status all all nodes of all le

Re: [HACKERS] The rewritting of join conditions caused a very slow query plan.

he distribution of rows for the join condition column even when possible. Thus, can we draw the conclusion that the current structure of all_level_status table is a bad design and should be avoided ? Chao. From: chang chao Sent: Monday, May 16, 2016 17:23 To: pgsql-hackers@postgresql.org

[HACKERS] explain analyze does not report actual rows correctly?

Hi all The test data and sql is in the following mail. http://www.postgresql.org/message-id/sg2pr06mb114954351fa5dae7566854a984...@sg2pr06mb1149.apcprd06.prod.outlook.com After I disabled hash join and nested-loop join(set enable_hashjoin = off; set enable_nestloop = off;) and execute the query