Stream Start (logical replication)

Logical replication Stream Start format. Identifies the message as a stream start message.

Reading PG 18·Select a recorded version

Layer: Logical replication payload; distinct from the frontend/backend message envelope
First field: Byte1('S')
manual path: /docs/18/protocol-logicalrep-message-formats.html
signature: Stream Start

Definition PG 18

Byte1('S'): Identifies the message as a stream start message.
Int32 (TransactionId): Xid of the transaction.
Int8: A value of 1 indicates this is the first stream segment for this XID, 0 for any other stream segment.

Fields in documented order

Position	Format	Meaning
1	Byte1('S')	Identifies the message as a stream start message.
2	Int32 (TransactionId)	Xid of the transaction.
3	Int8	A value of 1 indicates this is the first stream segment for this XID, 0 for any other stream segment.

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Complete source facts

fields

map[description:Identifies the message as a stream start message. format:Byte1('S')], map[description:Xid of the transaction. format:Int32 (TransactionId)], map[description:A value of 1 indicates this is the first stream segment for this XID, 0 for any other stream segment. format:Int8]

Source references

Full definition and evidence JSON

Definition sources

center · PostgreSQL 18 · 555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f