PostgreSQL Source Code

Hacking PostgreSQL

Final Code

PostgreSQL Subsystems

Hacking the PostgreSQL Way

Memory Management

Error Handling / Logging

Catalog Lookups

Nodes

Datums and Tuples

Other Subsystems

Datums

General structure for a given single value

Defined in postgres.h

Lots of helper routines for working with Datums

Int32GetDatum(int) - Returns Datum representation of an Int32

DatumGetInt32(Datum) - Returns int32 from a Datum

Many others for each data type

Datums may be stored ”out-of-line” (aka TOAST’d)