Data Import and Export

safe_data_path

Parameter Description: Sets the path prefix restrictions for users other than the initial user, currently including restrictions on copy and advanced package paths.

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

Value Range: String (less than 4096 characters)

Default Value: NULL

Note:

• If there are symbolic link files under the safe_data_path directory, they will be processed according to the actual file path they point to. If the actual path is not under safe_data_path, an error will be reported.
• If there are hard link files under the safe_data_path directory, they can be used normally. For safety reasons, please use hard link files cautiously, avoid creating hard links in the safe_data_path directory that point outside the directory, and ensure that the permissions for the safe_data_path directory are minimized.

enable_copy_server_files

Parameter Description: Whether to enable the permission for copy server-side files.

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

Value Range: Boolean

• on indicates that the permission for copy server-side files is enabled.

• off indicates that the permission for copy server-side files is not enabled.

Default Value: off

enable_delta_store

Parameter Description: To enhance the performance of single-row data import and solve disk redundancy issues for columnar storage, this parameter can be used to select whether to enable the support for columnar storage delta table functionality. When this parameter is enabled, data imported into a columnar storage table will be directed to delta table storage or main table CU storage based on the DELTAROW_THRESHOLD specified in the CREATE TABLE section when the table is defined. Data will enter the delta table when the data volume is less than DELTAROW_THRESHOLD.

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

Value Range: Boolean

• on indicates that the columnar storage delta table feature is enabled.

• off indicates that the columnar storage delta table feature is not enabled.

Default Value: off

partition_max_cache_size

Parameter Description: To optimize bulk insertions into columnar storage partitioned tables, data is cached before being written to disk in bulk. The partition_max_cache_size can specify the size of the data cache area. Setting this value too high will consume more system memory resources; setting it too low will reduce the performance of bulk insertions into columnar storage partitioned tables.

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

Value Range:

Columnar storage partitioned tables: 4096 to INT_MAX / 2, with the minimum unit being KB.

Default Value: 2GB

partition_mem_batch

Parameter Description: To optimize bulk insertions into columnar storage partitioned tables, data is cached before being written to disk in bulk. The partition_mem_batch can specify the number of cache batches. Setting this value too high will consume more system memory resources; setting it too low will reduce the performance of bulk insertions into columnar storage partitioned tables.

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

Value Range:

Columnar storage partitioned tables: 4096 to INT_MAX / 2, with the minimum unit being KB.

Default Value: 2GB

raise_errors_if_no_files

Parameter Description: Whether to differentiate between "empty import file record count" and "import file does not exist" during import. If raise_errors_if_no_files=TRUE, an error will be thrown when "import file does not exist."

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

Value Range: Boolean

• on indicates that a distinction should be made between "empty import file record count" and "import file does not exist" during import.

• off indicates that no distinction should be made between "empty import file record count" and "import file does not exist" during import.

Default Value: off