TupleData (logical replication)

Logical replication TupleData format. Number of columns.

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Layer: Logical replication payload; distinct from the frontend/backend message envelope
First field: Int16
manual path: /docs/18/protocol-logicalrep-message-formats.html
signature: TupleData

版本定义 PG 18

Int16: Number of columns.

Next, one of the following submessages appears for each published column:

Byte1('n'): Identifies the data as NULL value.

Byte1('u'): Identifies unchanged TOASTed value (the actual value is not sent).

Byte1('t'): Identifies the data as text formatted value.

Byte1('b'): Identifies the data as binary formatted value.
Int32: Length of the column value.
Byten: The value of the column, either in binary or in text format. (As specified in the preceding format byte). n is the above length.

Fields in documented order

Position	Format	Meaning
1	Int16	Number of columns.
2	Byte1('n')	Identifies the data as NULL value.
3	Byte1('u')	Identifies unchanged TOASTed value (the actual value is not sent).
4	Byte1('t')	Identifies the data as text formatted value.
5	Byte1('b')	Identifies the data as binary formatted value.
6	Int32	Length of the column value.
7	Byte n	The value of the column, either in binary or in text format. (As specified in the preceding format byte). n is the above length.

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完整来源事实

fields

map[description:Number of columns. format:Int16], map[description:Identifies the data as NULL value. format:Byte1('n')], map[description:Identifies unchanged TOASTed value (the actual value is not sent). format:Byte1('u')], map[description:Identifies the data as text formatted value. format:Byte1('t')], map[description:Identifies the data as binary formatted value. format:Byte1('b')], map[description:Length of the column value. format:Int32], map[description:The value of the column, either in binary or in text format. (As specified in the preceding format byte). n is the above length. format:Byte n]

来源引用

完整定义与证据 JSON

定义来源

center · PostgreSQL 18 · 555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f