Session Parameters

Session-level configuration with SET/SHOW.

SET variable = value;           -- session-scoped
SET LOCAL variable = value;     -- transaction-scoped
SHOW variable;
SHOW ALL;                       -- list all parameters
RESET variable;
RESET ALL;

-- Functions
SELECT current_setting('variable_name');
SELECT set_config('variable_name', 'value', false);

PostgreSQL-Compatible Parameters

Parameter	Default	Mutable	Description
`application_name`	`''`	Yes	Application name for the session
`bytea_output`	`hex`	Yes	Output format for bytea values
`client_encoding`	`UTF8`	Yes	Client-side character encoding
`client_min_messages`	`notice`	Yes	Minimum message severity sent to client
`datestyle`	`ISO, MDY`	No	Date display format
`default_transaction_isolation`	`read committed`	No	Default isolation level
`default_transaction_read_only`	`off`	Yes	Default read-only state for new transactions
`extra_float_digits`	`1`	Yes	Extra precision for floating-point output
`search_path`	`$user, public`	Yes	Schema search order
`server_encoding`	`UTF8`	No	Server-side character encoding
`server_version`	`16.0`	No	Reported PostgreSQL version
`standard_conforming_strings`	`on`	Yes	Treat backslashes literally in strings
`statement_timeout`	`60000ms`	Yes	Query timeout (0 = no limit)
`timezone`	`UTC`	Yes	Session timezone
`transaction_isolation`	`repeatable read`	Yes	Current transaction isolation level
`work_mem`	`4MB`	Yes	Memory for sort operations
`lock_timeout`	`0`	Yes	Lock acquisition timeout
`password_encryption`	`scram-sha-256`	Yes	Password hashing algorithm
`max_identifier_length`	`63`	Yes	Maximum identifier length
`lc_messages`	`C`	Yes	Locale for messages

Other accepted PostgreSQL parameters: check_function_bodies, default_table_access_method, default_tablespace, default_text_search_config, default_transaction_deferrable, idle_in_transaction_session_timeout, in_hot_standby, integer_datetimes, intervalstyle, lc_monetary, lc_numeric, lc_time, max_index_keys, row_security, xmloption.

DB9-Specific Parameters

Parameter	Default	Description
`db9.dml_table_scan_max_rows`	`10000`	Max rows per auxiliary source for UPDATE FROM / DELETE USING (0 = unlimited)
`db9.max_sort_bytes`	`256MB`	Memory limit for sort operations
`db9.prepared_plan_cache_size`	`128`	Prepared statement plan cache size
`db9.prepared_plan_cache_min_exec`	`5`	Min executions before plan cache promotion
`db9.retry_max_attempts`	`64`	Max retry attempts for autocommit DML/DDL on write conflict
`db9.retry_timeout`	`0`	Max wall-time for retries per statement (0 = no limit)
`db9.use_optimizer`	`on`	Cost-based optimizer (always on, immutable)

Embedding Parameters

Parameter	Default	Description
`embedding.provider`	—	Embedding provider: `openai` or `bedrock`
`embedding.endpoint`	—	Embedding service endpoint URL
`embedding.model`	—	Model name
`embedding.api_key`	—	Embedding service API key
`embedding.dimensions`	—	Output vector dimensions
`embedding.concurrency`	`5`	Max concurrent embedding calls
`embedding.max_calls`	`100`	Max embedding calls per statement

Vector Index Parameters

Parameter	Default	Description
`hnsw.ef_search`	`40`	Dynamic candidate list size for HNSW index search