PostgreSQL maintains Write Ahead Logging to keep records of transactions of database server. And keeps WALs in pg_xlog (Version 9.x and earlier) / pg_wal (Version 10.x and later) directory. However these WALs remains temporarily in this directory and overwrites WALs in Round Robin fashion depending upon configured wal_keep_segments parameter in postgresql.conf file. But these WALs can be archived to different permanent location where it will never be overwritten. Archived WALs plays major role in crash recovery or Point In Time […]