Preset Options

Preset Options

• block_size: Size of a table/index page: 8 kB, fixed when PostgreSQL is compiled.
• data_checksums: Whether every data page carries a checksum to detect storage corruption (PG18: on by default).
• data_directory_mode: File permissions of the data directory (0700, or 0750 with group access).
• debug_assertions: Whether this build has internal assertion checks compiled in (development builds only).
• huge_pages_status: PG17+: whether shared memory actually got huge pages (on / off / unknown).
• in_hot_standby: PG14+: on while the server is a standby accepting read-only queries.
• integer_datetimes: Whether timestamps are stored as 64-bit integers. Always on since PostgreSQL 10.
• max_function_args: Maximum number of arguments a function or procedure can take (100).
• max_identifier_length: Longest allowed name for a table, column, index … (63 bytes); longer names are truncated.
• max_index_keys: Maximum number of columns in one index, including INCLUDE columns (32).
• num_os_semaphores: PG18+: how many OS semaphores this configuration needs (computed at startup).
• segment_size: Max size of one table file on disk before PostgreSQL starts a new one (1 GB).
• server_encoding: Character set of the current database (usually UTF8), fixed when the database is created.
• server_version: The PostgreSQL version string, e.g. "18.6", as reported to clients.
• server_version_num: The server version as an integer (180006), easy to compare in scripts.
• shared_memory_size: PG15+: total size of the main shared memory area, computed from your settings.
• shared_memory_size_in_huge_pages: PG15+: number of huge pages needed for shared memory (for vm.nr_hugepages).
• ssl_library: Name of the SSL/TLS library PostgreSQL was built with (OpenSSL), empty if none.
• wal_block_size: Size of a WAL page (8 kB), fixed when PostgreSQL is compiled.
• wal_segment_size: Size of each WAL file in pg_wal (16 MB by default), chosen at initdb.