Configuration Parameter Categories

Configuration parameters affect categories of server behaviors, such as resource consumption, query tuning, and authentication. The following sections describe HAWQ configuration parameter categories.

Append-Only Table Parameters

The following parameters configure the append-only tables feature of HAWQ.

Client Connection Default Parameters

These configuration parameters set defaults that are used for client connections.

Statement Behavior Parameters

Locale and Formatting Parameters

Other Client Default Parameters

Connection and Authentication Parameters

These parameters control how clients connect and authenticate to HAWQ.

Connection Parameters

Security and Authentication Parameters

Database and Tablespace/Filespace Parameters

The following parameters configure the maximum number of databases, tablespaces, and filespaces allowed in a system.

Error Reporting and Logging Parameters

These configuration parameters control HAWQ logging.

Log Rotation

When to Log

What to Log

External Table Parameters

The following parameters configure the external tables feature of HAWQ.

GPORCA Parameters

These parameters control the usage of GPORCA by HAWQ. For information about GPORCA, see About GPORCA.

HAWQ Array Configuration Parameters

The parameters in this topic control the configuration of the HAWQ array and its components: segments, master, distributed transaction manager, master mirror, and interconnect.

Interconnect Configuration Parameters

Dispatch Configuration Parameters

Fault Operation Parameters

Filepace Parameters

Master Configuration Parameters

Read-Only Parameters

Segment Configuration Parameters

HAWQ PL/Java Extension Parameters

The parameters in this topic control the configuration of HAWQ PL/Java extensions.

HAWQ Resource Management Parameters

The following configuration parameters configure the HAWQ resource management feature.

Lock Management Parameters

These configuration parameters set limits for locks and deadlocks.

Past PostgreSQL Version Compatibility Parameters

The following parameters provide compatibility with older PostgreSQL versions. You do not need to change these parameters in HAWQ.

Query Tuning Parameters

These parameters control aspects of SQL query processing such as query operators and operator settings and statistics sampling.

Legacy Query Optimizer Operator Control Parameters

The following parameters control the types of plan operations the legacy query optimizer can use. Enable or disable plan operations to force the legacy optimizer to choose a different plan. This is useful for testing and comparing query performance using different plan types.

Legacy Query Optimizer Costing Parameters

Warning: Do not adjust these query costing parameters. They are tuned to reflect HAWQ hardware configurations and typical workloads. All of these parameters are related. Changing one without changing the others can have adverse affects on performance.

Database Statistics Sampling Parameters

These parameters adjust the amount of data sampled by an ANALYZE operation. Adjusting these parameters affects statistics collection system-wide. You can configure statistics collection on particular tables and columns by using the ALTER TABLE SET STATISTICS clause. See About Database Statistics.

Sort Operator Configuration Parameters

Aggregate Operator Configuration Parameters

Join Operator Configuration Parameters

Other Legacy Query Optimizer Configuration Parameters

Statistics Collection Parameters

Automatic Statistics Collection

When automatic statistics collection is enabled, you can run ANALYZE automatically in the same transaction as an INSERT, UPDATE, DELETE, COPY or CREATE TABLE...AS SELECT statement when a certain threshold of rows is affected (on_change), or when a newly generated table has no statistics (on_no_stats). To enable this feature, set the following server configuration parameters in your HAWQ hawq-site.xml file by using the hawq config utility and restart HAWQ:

Runtime Statistics Collection Parameters

These parameters control the server statistics collection feature. When statistics collection is enabled, you can access the statistics data using the pg_stat and pg_statio family of system catalog views.

System Resource Consumption Parameters

These parameters set the limits for system resources consumed by HAWQ.

Memory Consumption Parameters

These parameters control system memory usage. You can adjust hawq_re_memory_overcommit_max to avoid running out of memory at the segment hosts during query processing. See also HAWQ Resource Management.

Free Space Map Parameters

These parameters control the sizing of the free space map, which contains expired rows. Use VACUUM to reclaim the free space map disk space.

OS Resource Parameters

Cost-Based Vacuum Delay Parameters

Warning: Avoid using cost-based vacuum delay because it runs asynchronously among the segment instances. The vacuum cost limit and delay is invoked at the segment level without taking into account the state of the entire HAWQ array

You can configure the execution cost of VACUUM and ANALYZE commands to reduce the I/O impact on concurrent database activity. When the accumulated cost of I/O operations reaches the limit, the process performing the operation sleeps for a while, Then resets the counter and continues execution

Transaction ID Management Parameters