Wiki / Protocol Messages / Bidirectional messages
CopyData
CopyData is a bidirectional protocol message. Identifies the message as COPY data.
Reading PostgreSQL 18.6.
Description
CopyData is a bidirectional protocol message. Identifies the message as COPY data.
- Direction
- Frontend ↔ backend
- First wire field
- Byte1('d')
- Field entries
- 3
- Documented flow contexts
- COPY Operations
Usage
CopyData (F & B)Framing and repetition
The complete definition below retains repetition, counts and conditional fields. A numbered table row is a documented field definition, not a fixed byte offset. Integer encodings and flow rules follow the same-version protocol chapter.
Wire fields in documented order
| Position | Format | Meaning |
|---|---|---|
| 1 | Byte1('d') | Identifies the message as COPY data. |
| 2 | Int32 | Length of message contents in bytes, including self. |
| 3 | Byte n | Data that forms part of a COPY data stream. Messages sent from the backend will always correspond to single data rows, but messages sent by frontends might divide the data stream arbitrarily. |
Manual definition
-
- Byte1('d')
-
Identifies the message as
COPYdata. - Int32
-
Length of message contents in bytes, including self.
- Byte
n -
Data that forms part of a
COPYdata stream. Messages sent from the backend will always correspond to single data rows, but messages sent by frontends might divide the data stream arbitrarily.
Related entries
Documentation and source
Source build
- Version
- 18.6
- Build
- https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2
- Source fingerprint
555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f
Compare versions
PostgreSQL 17 → 18: unchanged.
Compares recorded interfaces and attributes. Source fingerprints and build metadata are excluded; an absent sample is not proof of the introduction or removal release.
Related entries
Export JSON · Back to Protocol Messages · Recorded in PostgreSQL 10 through 20; the first sample is not necessarily its introduction.