server configuration

The PostgreSQL development team provided a progress update on PostgreSQL 12, highlighting several enhancements: - Just-in-Time (JIT) compilation will be enabled by default, reducing memory consumption during COPY operations and function calls, and improving search performance for multi-byte characters. - Server configuration improvements will allow enabling/disabling cluster checksums via pg_checksums, reduce the default value for autovacuum_vacuum_cost_delay to 2ms, and support micro-seconds for time-based server variables. - Speed improvements for btree index insertions will enhance space efficiency of page splits, reducing locking overhead and optimizing performance for UPDATEs and DELETEs with many duplicates. - Recovery parameters can be modified during reloads, including archive_cleanup_command, promote_trigger_file, recovery_end_command, and recovery_min_apply_delay, along with a new streaming replication timeout feature. - The peculiar behavior of OID columns will likely be phased out, but they will still be defined as type OID, requiring adjustments for operations on tables with OID-named columns. - Data types such as abstime, reltime, and tinterval are expected to be removed. - Enhancements to geometric functions and operators will improve results, and geometric types will be restructured to manage NaN, underflow, overflow, and division by zero scenarios.