> 28 дек. 2020 г., в 11:14, Andrey Borodin <x4...@yandex-team.ru> написал(а): > >> Thanks for the patch. Maybe we can allow setting custom compression >> methods for wal compression as well. > > No, unfortunately, we can't use truly custom methods. Custom compression > handlers are WAL-logged. So we can use only static set of hardcoded > compression methods.
So, I've made some very basic benchmarks on my machine [0]. With pglz after checkpoint I observe 1146 and 1225 tps. With lz4 I observe 1485 and 1524 tps. Without wal_compression I see 1529 tps. These observations can be explained with plain statement: pglz is bottleneck on my machine, lz4 is not. While this effect can be reached with other means [1] I believe having lz4 for WAL FPIs would be much more CPU efficient. FPA lz4 for WAL FPI patch v17. Changes: fixed some frontend issues, added some comments. Best regards, Andrey Borodin. [0] https://yadi.sk/d/6y5YiROXQRkoEw [1] https://www.postgresql.org/message-id/flat/25991595-1848-4178-AA57-872B10309DA2%40yandex-team.ru#e7bb0e048358bcff281011dcf115ad42
v17-0007-Add-Lz4-compression-to-WAL-FPIs.patch
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