> Just because of ... heap_open()->RelationBuildDesc() does it.
> Maybe we could delay smgropen?
>
> But in any case note that big guys have shared catalog cache,
> and this is not because of they haven't good buffer pool -:)
> Keeping page in pool for just single row is not good.
>
> "Oracle itself accesses the data dictionary frequently during
> the parsing of SQL statements. This access is essential to the
> continuing operation of Oracle. See Chapter 8, "The Data Dictionary,"
> for more information on the data dictionary.
>
> ...
>
> Caching of the Data Dictionary for Fast Access
>
> Because Oracle constantly accesses the data dictionary during database
> operation to validate user access and to verify the state of objects,
> much of the data dictionary information is cached in the SGA. All
> information is stored in memory using the LRU (least recently
> used) algorithm. Information typically kept in the caches is that
> required for parsing."
I agree we need it. I just think we could use better fsync more, and
seeing how hard shared catalog cache may be, it may be good to get fsync
faster first.
-- 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