Re: Tablespace-level Block Size Definitions - Mailing list pgsql-hackers

From Zeugswetter Andreas DAZ SD
Subject Re: Tablespace-level Block Size Definitions
Date
Msg-id E1539E0ED7043848906A8FF995BDA5790C5186@m0143.s-mxs.net
Whole thread Raw
In response to Tablespace-level Block Size Definitions  ("Jonah H. Harris" <jharris@tvi.edu>)
Responses Re: Tablespace-level Block Size Definitions
List pgsql-hackers
> The problem I see with this proposal is that the buffer manager knows
> how to handle only a equally-sized pages.  And the shared memory stuff
> gets sized according to size * num_pages.  So what happens if a certain
> tablespace A with pagesize=X gets to have a lot of its pages cached,
> evicting pages from tablespace B with pagesize=Y, where Y < X?

You could create a separate bufferpool per page size. Of course that
has other disadvantages.

Is it really so difficult to create and attach another shmem segment ?

Andreas


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