On Thu, Dec 27, 2018 at 05:52:14PM -0500, Ravi Krishna wrote: > Unlogged tables are not stored in the catalog like a regular table. When > it is converted to a logged table , the entire operation is logged (goes > into wal logs) in one single transaction, blocking the entire table > during the process. IMO this makes unlogged -> logged workflow not a > right fit for large tables. In other products I have used, large tables > are set to unlogged mode before bulk load and then set back to normal > logged mode. If you are interested of how things happen at code level, you can grep for INIT_FORKNUM, which is the initial state of an unlogged table used when doing crash recovery. And while the main fork's data is never WAL-logged, this initial fork needs to be included in WAL. -- Michael
Attachment:
signature.asc
Description: PGP signature
