Re: [NOVICE] Extreme high load averages
От | Martin Foster |
---|---|
Тема | Re: [NOVICE] Extreme high load averages |
Дата | |
Msg-id | 3F0E54A2.4040604@ethereal-realms.org обсуждение исходный текст |
Ответ на | Re: [NOVICE] Extreme high load averages ("Shridhar Daithankar" <shridhar_daithankar@persistent.co.in>) |
Список | pgsql-performance |
Shridhar Daithankar wrote: > On 10 Jul 2003 at 0:43, Martin Foster wrote: > >>As for creating a new table, that in itself is a nice idea. But it >>would cause issues for people currently in the realm. Their posts >>would essentially dissapear from site and cause more confusion then its >>worth. > > > No they won't. Say you have a base table and your current post table is child > of that. You can query on base table and get rows from child table. That way > all the data would always be there. > > While inserting posts, you would insert in child table. While qeurying you > would query on base table. That way things will be optimal. > > >>Inheritance would work, but the database would essentially just grow and >>grow and grow right? > > > Right. But there are two advantages. > > 1. It will always contain valid posts. No dead tuples. > 2. You can work in chuncks of data. Each child table can be dealt with > separately without affecting other child tables, whereas in case of a single > large table, entire site is affected.. > > Deleting 100K posts from 101K rows table is vastly different than deleting 10K > posts from 2M rows table. Later one would unnecessary starve the table with > dead tuples and IO whereas in former case you can do create table as select > from and drop the original.. > > HTH > > Bye > Shridhar > > -- > "[In 'Doctor' mode], I spent a good ten minutes telling Emacs what Ithought of > it. (The response was, 'Perhaps you could try to be lessabusive.')"(By Matt > Welsh) > When I ran EXPLAIN on the views and queries making use of the inherited tables, I noticed that everything worked based on sequence scans and it avoided all indexes. While making use of ONLY kicked in full indexes. This is even after having created a child table with the same indexes as the parent. Is this a known issue, or just some sort of oddity on my setup? Tables still cannot be removed easily, but I found a way to work around it for a day-to-day basis. Essentailly I just clean out the tables containing old rows and delete them later. However based on the above, I doubt performance would get any better. Thanks for the advice however! Martin Foster Creator/Designer Ethereal Realms martin@ethereal-realms.org
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