Igeometry Podcast
Postgres is combining IO in version 17
- Author: Vários
- Narrator: Vários
- Publisher: Podcast
- Duration: 0:27:39
- More information
Informações:
Synopsis
Learn more about database and OS internals, check out my courses Fundamentals of database engineering https://databases.win Fundamentals of operating systems https://oscourse.win This new PostgreSQL 17 feature is game changer. You see, postgres like most databases work with fixed size pages. Pretty much everything is in this format, indexes, table data, etc. Those pages are 8K in size, each page will have the rows, or index tuples and a fixed header. The pages are just bytes in files and they are read and cached in the buffer pool. To read page 0, for example, you would call read on offset 0 for 8192 bytes, To read page 1 that is another read system call from offset 8193 for 8192, page 7 is offset 57,345 for 8192 and so on. If table is 100 pages stored a file, to do a full table scan, we would be making 100 system calls, each system call had an overhead (I talk about all of that in my OS course). The enhancement in Postgres 17 is to combine I/Os you can specify how much IO to combine, so technicall