pg_backend_memory_contexts

The view pg_backend_memory_contexts displays all the memory contexts of the server process attached to the current session. pg_backend_memory_contexts contains one row for each memory context.

First seen PG 14Last seen PG 19Columns 10

9.0 9.1 9.2 9.3 9.4 9.5 9.6 10 11 12 13 14 15 16 17 18 19^β3

Checked column by column against a PostgreSQL 18.6 instance · Raw measurement record ↗

Columns PostgreSQL 18

pg_backend_memory_contexts

COLUMN	TYPE	DESCRIPTION
`name`	`text`	Name of the memory context
`ident`	`text`	Identification information of the memory context. This field is truncated at 1024 bytes
`type`	`text`	Type of the memory context
`level`	`integer`Documented as:`int4`	The 1-based level of the context in the memory context hierarchy. The level of a context also shows the position of that context in the path column.
`path`	`integer[]`Documented as:`int4[]`	Array of transient numerical identifiers to describe the memory context hierarchy. The first element is for TopMemoryContext, subsequent elements contain intermediate parents and the final element contains the identifier for the current context.
`total_bytes`	`bigint`Documented as:`int8`	Total bytes allocated for this memory context
`total_nblocks`	`bigint`Documented as:`int8`	Total number of blocks allocated for this memory context
`free_bytes`	`bigint`Documented as:`int8`	Free space in bytes
`free_chunks`	`bigint`Documented as:`int8`	Total number of free chunks
`used_bytes`	`bigint`Documented as:`int8`	Used space in bytes

Columns marked "implicit" are not included in SELECT *; some early statistics views are completed from same-version source, and the extra provenance is shown in the column description.

Column evolution matrix

Hover a cell for the column type

PresentAdded / type or attribute changeRemoved

COLUMN	9.0	9.1	9.2	9.3	9.4	9.5	9.6	10	11	12	13	14	15	16	17	18	19
`name`	–	–	–	–	–	–	–	–	–	–	–
`ident`	–	–	–	–	–	–	–	–	–	–	–
`parent`	–	–	–	–	–	–	–	–	–	–	–					−	–
`level`	–	–	–	–	–	–	–	–	–	–	–
`total_bytes`	–	–	–	–	–	–	–	–	–	–	–
`total_nblocks`	–	–	–	–	–	–	–	–	–	–	–
`free_bytes`	–	–	–	–	–	–	–	–	–	–	–
`free_chunks`	–	–	–	–	–	–	–	–	–	–	–
`used_bytes`	–	–	–	–	–	–	–	–	–	–	–
`type`	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–
`path`	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–

9.0 is the coverage baseline; a column already present in the baseline is not marked as added. The matrix aligns columns by name, so a rename appears as the old column removed and a new column added.

Evolution timeline

Changes between adjacent majors

PostgreSQL 18 ← 17

+ type+ path− parent1 column description updates

PostgreSQL 14 ← 13Catalog added

+ name+ ident+ parent+ level+ total_bytes+ total_nblocks+ free_bytes+ free_chunks+ used_bytes

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FROMTOInclude description updates

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