Re: [HACKERS] LONG
От | Bruce Momjian |
---|---|
Тема | Re: [HACKERS] LONG |
Дата | |
Msg-id | 199912122204.RAA09403@candle.pha.pa.us обсуждение исходный текст |
Ответ на | Re: [HACKERS] LONG (wieck@debis.com (Jan Wieck)) |
Список | pgsql-hackers |
> Bruce Momjian wrote: > > > I disagree. By moving to another table, we don't have non-standard > > tuples in the main table. We can create normal tuples in the long* > > table, of identical format, and access them just like normal tuples. > > Having special long tuples in the main table that don't follow the > > format of the other tuples it a certain mess. The long* tables also > > move the long data out of the main table so it is not accessed in > > sequential scans. Why keep them in the main table? > > More ugly and complicated (especially for VACUUM) seems to > me, the we need an index on these nonstandard tuples, that > doesn't see the standard ones, while the regular indices > ignore the new long tuples. At least if we want to delay > reading of long values until they're explicitly requested. > Yes, good point. No reason to create non-standard tuples if you can avoid it. And a separate table has performance advantages, especially because the long tuples are by definition long and take up lots of blocks. -- Bruce Momjian | http://www.op.net/~candle maillist@candle.pha.pa.us | (610) 853-3000+ If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill, Pennsylvania19026
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