Question

I’m working on a database with mysql 5.0 for an open source project
it’s used to stored sentences in specific languages and their translations in other languages

I used to have a big table “sentences” and “sentences_translations” (use to join sentences to sentences) table but has we have now near one million entries, this begin to be a bit slow, moreover, most of request are made using a “where lang =”

so I’ve decided to create a table by language
sentences_LANGUAGECODE

and sentences_translation_LANGSOURCE_LANGTARGET

and to create merge table like this
sentences_ENG_OTHERS which merge sentences_ENG_ARA sentences_ENG_DEU etc…
when we want to have the translations in all languages of an english sentence
sentences_OTHERS_ENG
when we want to have only the english translations of some sentences

I’ve created a script to create all these tables (they’re around 31 languages so more than 60 merge table), I’ve tested, that works really great a request which use to take 160ms now take only 30 🙂
but I discover that all my merge table after the 15th use to have “NULL” as type of storage engine
instead of MRG_MYISAM, and if delete one, then I can create an others, using FLUSH table between each creation also allow me to create more merge tables

so is this a limitation from mysql ? can we override it ?

thanks for your answers

Answer 1

(thanks to Martin to show me the way)

on linux, you have to edit your /etc/security/limits.conf and a line like this

* hard nofile 4096

At the next restart it will be ok
To have it directly stop your server

ulimit -n 4096 (or more , as root)

and restart your server directly

I don’t know how about windows yet