The following tables list the custom parameters available for PolarDB for Oracle, grouped by functional area. Parameters marked Yes in the Restart required column take effect only after you restart the cluster.
Autovacuum
| Parameter name | Valid value | Restart required | Description |
|---|
| autovacuum_max_workers | [5-20] | Yes | Sets the maximum number of simultaneously running autovacuum worker processes. |
| autovacuum_vacuum_cost_delay | [-1-100] | No | Vacuum cost delay in milliseconds, for autovacuum. |
| autovacuum_vacuum_cost_limit | [-1-10000] | No | Vacuum cost amount available before napping, for autovacuum. |
| vacuum_defer_cleanup_age | [0-1000000] | No | Number of transactions by which VACUUM and HOT cleanup should be deferred, if any. |
auto_explain
| Parameter name | Valid value | Restart required | Description |
|---|
| auto_explain.log_analyze | [on|off] | No | Use EXPLAIN ANALYZE for plan logging. |
| auto_explain.log_buffers | [on|off] | No | Log buffers usage. |
| auto_explain.log_format | [text|xml|json|yaml] | No | EXPLAIN format to be used for plan logging. |
| auto_explain.log_min_duration | [-1-2147483647] | No | Sets the minimum execution time above which plans will be logged. |
| auto_explain.log_nested_statements | [on|off] | No | Log nested statements. |
| auto_explain.log_timing | [on|off] | No | Collect timing data, not just row counts. |
| auto_explain.log_triggers | [on|off] | No | Include trigger statistics in plans. |
| auto_explain.log_verbose | [on|off] | No | Use EXPLAIN VERBOSE for plan logging. |
| auto_explain.sample_rate | [0-1] | No | Fraction of queries to process. |
Parallel query
| Parameter name | Valid value | Restart required | Description |
|---|
| enable_partitionwise_aggregate | [on|off] | No | Enables partitionwise aggregation and grouping. |
| enable_partitionwise_join | [on|off] | No | Enables partitionwise join. |
| max_parallel_workers | [0-512] | No | Sets the maximum number of parallel workers that can be active at one time. |
| max_parallel_workers_per_gather | [0-512] | No | Sets the maximum number of parallel processes per executor node. |
| min_parallel_index_scan_size | [0-715827882] | No | Sets the minimum amount of index data for a parallel scan. |
| min_parallel_table_scan_size | [0-715827882] | No | Sets the minimum amount of table data for a parallel scan. |
Logging
| Parameter name | Valid value | Restart required | Description |
|---|
| log_min_duration_statement | [-1-2147483647] | No | Sets the minimum execution time above which statements will be logged. |
| log_statement | [none|ddl|mod|all] | No | Sets the type of statements logged. |
| log_temp_files | [-1-2147483647] | No | Log the use of temporary files larger than this number of kilobytes. |
| track_commit_timestamp | [on|off] | Yes | Collects transaction commit time. |
Sessions and transactions
| Parameter name | Valid value | Restart required | Description |
|---|
| default_transaction_deferrable | [on|off] | No | Sets the default deferrable status of new transactions. |
| extra_float_digits | [-15-3] | No | Sets the number of digits displayed for floating-point values. |
| idle_in_transaction_session_timeout | 0 or [1000-2000000000] | No | Sets the maximum allowed duration of any idling transaction. |
| jit | [on|off] | No | Allow JIT compilation. |
| lock_timeout | 0 or [1000-2000000000] | No | Sets the maximum allowed duration of any wait for a lock. |
| old_snapshot_threshold | [-1-86400] | Yes | Time before a snapshot is too old to read pages changed after the snapshot was taken. |
| statement_timeout | 0 or [1000-2000000000] | No | Sets the maximum allowed duration of any statement. |
| temp_file_limit | [-1-1048576000] | No | Limits the total size of all temporary files used by each process. |
| timezone | ^'(((UTC)(-){0,1}(d|[1-9]d|1([0-5]d|6[0-7])))|((GMT)(-){0,1}(d|[1-9]d|1([0-5]d|6[0-7])))|CST6CDT|Poland|Kwajalein|MST|NZ|Universal|Libya|Turkey|EST5EDT|Greenwich|NZ-CHAT|MET|Portugal|GMT-0|CET|Eire|PST8PDT|Jamaica|GMT|Zulu|Japan|ROC|GB-Eire|ROK|Navajo|Singapore|posixrules|GB|EST|GMT0|Hongkong|PRC|Iran|MST7MDT|WET|W-SU|UCT|Cuba|Egypt|EET|Israel|UTC|HST|Iceland)'$ | No | Sets the time zone for displaying and interpreting time stamps. |
| work_mem | [4096-524288] | No | Sets the maximum memory to be used for query workspaces. |
WAL and replication
| Parameter name | Valid value | Restart required | Description |
|---|
| max_sync_workers_per_subscription | [0-262143] | No | Maximum number of table synchronization workers per subscription. |
| wal_level | [replica|logical] | Yes | Set the level of information written to the WAL. |
PolarDB-specific parameters
These parameters are specific to PolarDB for Oracle and control Oracle-compatibility behavior and dynamic tuning.
| Parameter name | Valid value | Restart required | Description |
|---|
| polar_comp_dynatune | [0-100] | Yes | Sets the PolarDB utilization percentage. |
| polar_comp_dynatune_profile | [oltp|reporting|mixed] | Yes | Sets the workload profile for dynatune. |
| polar_comp_enable_pruning | [on|off] | No | Enables the planner to early-prune partitioned tables. |
| polar_comp_redwood_date | [on|off] | No | Determines whether DATE should behave like TIMESTAMP or not. |
| polar_comp_redwood_greatest_least | [on|off] | No | Determines whether GREATEST AND LEAST function should behave like Redwood or PG. |
| polar_comp_redwood_raw_names | [on|off] | No | Return the unmodified name stored in the PostgreSQL system catalogs from Redwood interfaces. |
| polar_comp_redwood_strings | [on|off] | No | Treat NULL as an empty string when concatenated with a TEXT value. |
| polar_comp_stmt_level_tx | [on|off] | No | Allows continuing on errors instead of requiring a transaction abort. |