Perumal Raj wrote: > We are planning to reclaim unused space from 9.2 Version postgres Cluster, > > Method : VACUUM FULL > DB Size : 500 GB > Expected space to reclaim 150 GB > work_mem : 250 MB > maintenance_work_mem : 20 GB > > Question : > > 1. vacuumdb --j option (Parallel) not available for version 9.2. > How to run vacuum full in parallel ? At present its taking 8Hrs if i run > sequential ( vacuum full verbose;)
Run several scripts in parallel, where each of them vacuums some bloated tables. Be warned that VACUUM (FULL) is quite I/O intense, so too much parallelism might overload your I/O system and harm performance. > 2. If we run vacuum full, Do we need to run REINDEX/ANALYZE exclusively ? You don't need to run REINDEX, because that happens automatically. You can use VACUUM (FULL, ANALYZE) to also gather statistics. > 3. What is the best way to run VACUUM FULL with less window. Identify which tables really need it rather than VACUUMing everything. Yours, Laurenz Albe -- Cybertec | https://www.cybertec-postgresql.com
