logical_decoding_work_mem is a configuration parameter specifying the maximum amount of memory to be used by logical decoding, before some of the decoded changes are written to local disk.
logical_decoding_work_mem was added in PostgreSQL 13.
The default value for
Prior to the introduction of this parameter, the decision on whether to spill logical decoding transactions to disk was made on the basis of the number of changes in a particular transaction. This parameter provided finer-grained control over this process and makes it possible to limit the memory usage of walsenders.