pg_backend_memory_contexts

The pg_backend_memory_contexts system view displays all of the memory contexts in use by the server process attached to the current session.

pg_backend_memory_contexts contains one row for each memory context.

column	type	description
gp_segment_id	int4	The segment ID of the memory context.
name	text	The name of the memory context.
ident	text	Identification information of the memory context. This field is truncated at 1024 bytes.
parent	text	The name of the parent of this memory context.
level	int4	The distance from TopMemoryContext in context tree.
total_bytes	int8	The total number of bytes allocated for this memory context.
total_nblocks	int8	The total number of blocks allocated for this memory context.
free_bytes	int8	Free space in bytes.
free_chunks	int8	The total number of free chunks.
used_bytes	int8	Used space in bytes.