AI Features

enable_hypo_index

Parameter description: Specifies whether the database optimizer considers the created virtual index when executing the EXPLAIN statement. By executing EXPLAIN on a specific query statement, you can evaluate whether the index can improve the execution efficiency of the query statement based on the execution plan provided by the optimizer.

This parameter is a USERSET parameter. Set it based on instructions provided in Table 1 GUC parameters.

Value range: Boolean

• on indicates that a virtual index is created during EXPLAIN execution.
• off indicates that no virtual index is created during EXPLAIN execution.

Default value: off

db4ai_snapshot_mode

Parameter description: There are two snapshot modes: MSS (materialized mode, storing data entities) and CSS (computing mode, storing incremental information).

This parameter is a USERSET parameter. Set it based on instructions provided in Table 1 GUC parameters.

Value range: a string, which can be MSS or CSS

• MSS indicates the materialized mode. The DB4AI stores data entities when snapshots are created.
• CSS indicates the computing mode. The DB4AI stores incremental information when creating snapshots.

Default value: MSS

db4ai_snapshot_version_delimiter

Parameter description: Specifies the delimiter for the snapshot version of a data table.

This parameter is a USERSET parameter. Set it based on instructions provided in Table 1 GUC parameters.

Value range: a string, consisting of one or more characters.

Default value: @

db4ai_snapshot_version_separator

Parameter description: Specifies the subversion delimiter of a data table snapshot.

This parameter is a USERSET parameter. Set it based on instructions provided in Table 1 GUC parameters.

Value range: a string, consisting of one or more characters.

Default value: .

unix_socket_directory

Parameter description: Specifies the path for storing files in the unix_socket communication mode. You can set this parameter only in the configuration file postgresql.conf. Before enabling the fenced mode, you need to set this GUC parameter.

This parameter is a POSTMASTER parameter. Set it based on instructions provided in Table 1 GUC parameters.

Value range: a string of 0 or more characters

Default value: "

enable_ai_stats

Parameter description: This parameter specifies whether to create or use smart statistics.

This parameter is a USERSET parameter. Set it based on instructions provided in Table 1 GUC parameters.

Value range: Boolean

Default value: on

enable_cachedplan_mgr

Parameter description: This parameter enables or disables adaptive schedule selection.

This parameter is a USERSET parameter. Set it based on instructions provided in Table 1 GUC parameters.

Value range: Boolean

Default value: on

multi_stats_type

Parameter description: This parameter is used to specify the category of statistics to be created when the parameter enable_ai_stats is on.

This parameter is a USERSET parameter. Set it based on instructions provided in Table 1 GUC parameters.

Value range: Enumeration type, valid values are “BAYESNET”, “MCV”, “ALL”.

• "BAYESNET"：Only smart statistics are created.

• "MCV"：Only traditional statistics are created.

• "ALL"：Create both traditional statistics and smart statistics.

Default value: "BAYESNET"