Re: Equivalent praxis to CLUSTERED INDEX?
От | Bruce Momjian |
---|---|
Тема | Re: Equivalent praxis to CLUSTERED INDEX? |
Дата | |
Msg-id | 200408271748.i7RHmfJ15766@candle.pha.pa.us обсуждение исходный текст |
Ответ на | Re: Equivalent praxis to CLUSTERED INDEX? (Adi Alurkar <adi@sf.net>) |
Ответы |
Re: Equivalent praxis to CLUSTERED INDEX?
Re: Equivalent praxis to CLUSTERED INDEX? Re: Equivalent praxis to CLUSTERED INDEX? Re: Equivalent praxis to CLUSTERED INDEX? |
Список | pgsql-performance |
Adi Alurkar wrote: > IIRC it it to reduce the "overflow" of data or what oracle calls > chained rows. i.e if a table has variable length columns and 10 rows > get inserted into a datapage, if this datapage is full and one of the > variable length field gets updated the row will now "overflow" into > another datapage, but if the datapage is created with an appropriate > amount of free space the updated row will be stored in one single > datapage. Agreed. What I am wondering is with our system where every update gets a new row, how would this help us? I know we try to keep an update on the same row as the original, but is there any significant performance benefit to doing that which would offset the compaction advantage? -- 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
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