Thanks everyone for the answers. Tested this PAGE_COMPRESSION a bit and make some reading. Not sure if I fully understand how that works... is that correct? 1. Impossible without punch hole as if we don't have it the server will just write partially used pages which will take full page size anyway. But in docs it seems it described its use with punch hole disabled. What's the reason to still have page compression without punch hole? 2. After enabling compression each page needs to be trimmed using punch hole, so if we have 1 TB database and 64k blocks, the database files will have over 15 million fragments ( 1000000000000/64000) So if we get like 50% compression and then we'll be able to put another 1TB of data into these holes we'll be having close to 31 million file fragments. I'm not sure if under such conditions the FS will be able to even allocate space efficiently anymore, copy these files, etc. Or im not getting something? 3. I was testing compression of ~1.5GB table with nice results on default 16kb page size. One thing i noticed is that l was always getting exactly the same compressed size using `du`. However the table read/copy times were different from 40s for uncompressed to 80-400 seconds depending on algo. Is that possible that is because page size is too low? 4. Myrocks seems to be very slow compared to compressed inno. Was also reading docs related to it. For its usecase is it more suitable for storing large rows rather than many small rows? 5. I remember reading that some innodb compression is going to be obsolete. Is that row compression? Or there are no plans to obsolete any compression model? Thanks. Dnia 16 sierpnia 2023 16:08 Gordan Bobic via discuss < [email protected] > napisał(a): Larger pages will yield higher compression ratios, as will zstd (slightly slower than lz4). Mileage varies, but on some of my databases, between the 64KB pages (zfs recordsize) and zstd, my compression ratios approximately doubled, from about 1.8:1 to a little under 4:1. This will all heavily depend on the type of data you are storing, though. zstd has adjustable compression, so if you have tons of CPU to spare, you could turn it up from the default of 3 (probably optimal cost/size compromise) to high teens for a compression boost. On Wed, 16 Aug 2023, 14:34 Reinis Rozitis, < [email protected] > wrote: > From: Gordan Bobic via discuss < [email protected] > > > One of the best compromises is to configure InnoDB with 64KB pages, put it on ZFS with recordsize=64K, and enable zstd compression on ZFS. Sorry for hijacking the thread a bit. After the discontinuation of tokudb I chose the innodb+zfs route (bad previous/early experience with rocks, also million knobs to adjust for your workload etc) but at that time didn't think of increasing the Innodb page size to 64KB - do you have any (even rough) numbers of 16 vs 64KB (on zfs)? Also, what would be the benefit of zstd vs lz4? Higher compression ratio? rr _______________________________________________ discuss mailing list -- [email protected] To unsubscribe send an email to [email protected]
_______________________________________________ discuss mailing list -- [email protected] To unsubscribe send an email to [email protected]
