[exim] Re: domainlist from mysql

[Cyborg via Exim-users]

Am 06.04.25 um 22:01 schrieb Mark Elkins via Exim-users:

In MYSQL - try:-

SELECT GROUP_CONCAT(domain SEPARATOR ':') AS domain FROM mail_domains

On 2025/04/06 21:43, Ray O'Donnell via Exim-users wrote:

I do the same thing using PostgreSQL - my lookup looks like this (built with help from this list):     MAIN_LOCAL_DOMAINS = @ : ${lookup pgsql{select string_agg(domain_name, ':') from domains where is_enabled = true}}

Please consider this:





This can easily be avoided. Two hints:

a) your select can not use an index because, you do not have a where clause


https://www.exim.org/exim-html-current/doc/html/spec_html/ch-domain_host_address_and_local_part_lists.html




best regards,
Cyborg

All those valid and working examples read in the entire list of domains. If your domainlist has 1 entry , it's fine. If it has 10, it's fine. If it hits 2000, you will have a small perfomance issue. Depending on your incoming mail numbers per second, it could be a bigger-than-you-think issue. The next thing that happens is, exim has to process that "immense" list, and if the desired value is at the end, it has wasted a lot of cpu cycles to get there, same as the database. b) there is an easy way to reduce the list to 1 result. you will find it in the middle of this document page: If one asks, why i do not post the final solution: it's a learning opportunity which will change away more in the exim config, than one might expect now.

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