Module submodules

Modules§

cmp
datum
elog: Access to Postgres’ logging system
errcodes
ffi
htup
oids
panic
pg_try
transaction_id
tupdesc: Provides helper implementations for various TupleDesc-related structs
utils: General utility functions

Datum: Datum is an abstract value that is effectively a union of all scalar types and all possible pointers in a Postgres context. That is, it is either “pass-by-value” (if the value fits into the platform’s uintptr_t) or “pass-by-reference” (if it does not).
Oid: An object identifier in Postgres.
PgTryBuilder: PgTryBuilder is a mechanism to mimic Postgres C macros PG_TRY and PG_CATCH.
TransactionId: An xid type from PostgreSQL

HeapTupleGetRawCommandId^⚠: HeapTupleHeaderGetRawCommandId will give you what’s in the header whether it is useful or not. Most code should use HeapTupleHeaderGetCmin or HeapTupleHeaderGetCmax instead, but note that those Assert that you can get a legitimate result, ie you are in the originating transaction!
HeapTupleHeaderFrozen^⚠: Does the specified HeapTupleHeaderData represent a “frozen” tuple?
HeapTupleHeaderGetNatts^⚠: How many attributes does the specified HeapTupleHeader have?
HeapTupleHeaderGetRawXmin^⚠: HeapTupleHeaderGetRawXmin returns the “raw” xmin field, which is the xid originally used to insert the tuple. However, the tuple might actually be frozen (via HeapTupleHeaderSetXminFrozen) in which case the tuple’s xmin is visible to every snapshot. Prior to PostgreSQL 9.4, we actually changed the xmin to FrozenTransactionId, and that value may still be encountered on disk.
HeapTupleHeaderGetXmin^⚠: Returns the xmin value of the specified HeapTupleHeaderData
HeapTupleHeaderIsHeapOnly^⚠: Safety
HeapTupleHeaderIsHotUpdated^⚠: Safety
HeapTupleHeaderXminInvalid^⚠: Safety
HeapTupleNoNulls^⚠: Does the specified HeapTuple contain nulls?
heap_getattr^⚠: Extract an attribute of a heap tuple and return it as a Datum. This works for either system or user attributes. The given attnum is properly range-checked.
name_data_to_str: Converts a pg_sys::NameData struct into a &str.