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A comment on Running PostgreSQL on Compression-enabled ZFS. Parent comment

Re:Running PostgreSQL on Compression-enabled ZFS by mbell on Monday April 22, 2013 @04:26PM (#5591571)
Another issue is that ZFS is extremely aggressive with caching data in ram (L1ARC). That can eat up memory you'd rather give to the database heap and also tends to skew benchmarks.
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Re:Running PostgreSQL on Compression-enabled ZFS by wiredfool on Monday April 22, 2013 @06:54PM (#5592227)
Yes, but postgres' design in that area actually helps. Postgres relies on the OS caching the data tables for the most part. There is some caching in shared buffers, but generally that's not a huge portion of the memory of your db system. (10-25%, and not more than a few gigs)
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Re:Running PostgreSQL on Compression-enabled ZFS by bsg75 on Monday April 22, 2013 @04:27PM (#5591578)
Placing limits on ARC (25% for me currently) limits that effect.
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Re:Running PostgreSQL on Compression-enabled ZFS by rscale on Monday April 22, 2013 @07:13PM (#5592308)
I run Postgres on ZFS, and simply limit the amount of memory dedicated to the ARC.
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