Re: Minor TODO list changes
От | Kenneth Marshall |
---|---|
Тема | Re: Minor TODO list changes |
Дата | |
Msg-id | 20041104170541.GB18703@it.is.rice.edu обсуждение исходный текст |
Ответ на | Re: Minor TODO list changes (Bruce Momjian <pgman@candle.pha.pa.us>) |
Список | pgsql-hackers |
Bruce, Just to chime in. I also agree that fillfactor is useful. I have been investigating different index variants and different fill factors can greatly influence the performance of the index. I also think it may play a key role in minimizing the small table/ many inserts/updates performance problem. --Ken On Thu, Nov 04, 2004 at 11:51:15AM -0500, Bruce Momjian wrote: > > OK, I updated all your items. I removed fillfactor because I thought I > was the only one who thought it was valuable and as I remember it was > mostly useful for ISAM, which we don't support. Can you think of a use > for a non-100% fillfactor? > > --------------------------------------------------------------------------- > > Simon Riggs wrote: > > A few minor typos/notes: > > > > INDEXES > > > > 1. On 2nd bullet... > > "The main difficulty with this item is the problem of creating an index > > that can spam more than one table." > > > > should be span, not spam > > > > 2. On 6th bullet > > * "Use index to restrict rows returned by multi-key index when used > > with non-consecutive keys to reduce heap accesses > > > > For an index on col1,col2,col3, and a WHERE clause of col1 = 5 and col3 > > = 9, spin though the index checking for col1 and col3 matches, rather > > than just col1 " > > > > This is also known as "skip-scanning", so it would be good to use that > > phrase in the TODO > > > > 3. Whatever happened to the FILLFACTOR todo item? AFAICS it disappeared > > sometime at the beginning of August, but I'm not sure why? > > > > REF INTEGRITY > > > > ...Didn't we just get rid of deferred triggers?? Perhaps I read that > > wrong. > > > > > > CACHE > > > > 1. 1st bullet....prefix it with "Use posix_fadvise() API to let OS know > > how files will be used by PostgreSQL. This would allow, for example, > > a..." (replacing the word "add"). > > > > > > > > -- > > Best Regards, Simon Riggs > > > > > > ---------------------------(end of broadcast)--------------------------- > > TIP 2: you can get off all lists at once with the unregister command > > (send "unregister YourEmailAddressHere" to majordomo@postgresql.org) > > > > -- > Bruce Momjian | http://candle.pha.pa.us > pgman@candle.pha.pa.us | (610) 359-1001 > + If your life is a hard drive, | 13 Roberts Road > + Christ can be your backup. | Newtown Square, Pennsylvania 19073 > > ---------------------------(end of broadcast)--------------------------- > TIP 8: explain analyze is your friend
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