PostgreSQL Computes Page Checksums Fast
Every page PostgreSQL writes to disk gets a checksum: two bytes in the page header that let the server notice, on the next read, that the page it just read is not the page it …
Postgres
PostgreSQL's Integer Type Implementation in C (int2, int4, int8)
PostgreSQL has three signed integer widths: int2 (2 bytes), int4 (4 bytes), and int8 (8 bytes). They are not three separate designs. They are one design instantiated three times: a …
PostgreSQL Deduplicates B-Tree Entries
Every index is a lie about multiplicity. A CREATE INDEX on a boolean column produces a structure in which, logically, there are only two distinct keys — but the index has to be …
PostgreSQL's Multirange Type Implementation in C
A multirange is what you get when you let a range type hold more than one range: int4multirange can be {[1,5),[10,20)}. The surprising thing is how little C there is to it. All six …
PostgreSQL Does Async I/O with io_uring
Every storage engine eventually runs into the same wall. You ask for a block, the block is not in memory, and the process blocks in the kernel until the disk spins around. It …