43.2.2 Format of unarchive chunk options

(1) Specification format

[set adb_unarcv_rthd_num = number-of-processing-real-threads-to-be-used-by-adbunarchivechunk-command]
[set adb_unarcv_read_size = buffer-size]
[set adb_unarcv_buff_blk_num = number-of-buffer-blocks-for-unarchiving-chunks]
[set adb_unarcv_sort_buff_size = sort-buffer-size]
[set adb_unarcv_dividx_rd_buff_size = B-tree-and-text-index-input-buffer-size]
[set adb_unarcv_dividx_wt_buff_size = B-tree-and-text-index-output-buffer-size]
[set adb_unarcv_txt_buff_size = buffer-size-for-creating-text-indexes]
[set adb_unarcv_decompress_buff_size = buffer-size-for-decompressing-archive-files]

The rules for specifying these unarchive chunk options are the same as for the server definition. For the rules for specifying server definitions, see the topic Syntax rules for the server definition in the HADB Setup and Operation Guide.

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(2) Explanation of specification format

• adb_unarcv_rthd_num = number-of-processing-real-threads-to-be-used-by-adbunarchivechunk-command

~<integer>((2 to 4,096))

Specifies the number of processing real threads to be used for executing the adbunarchivechunk command.

Specification of this option is recommended. The adbunarchivechunk command uses the number of processing real threads specified in this option. Therefore, specify an appropriate number of processing real threads for use by the adbunarchivechunk command. For details about the processing of the adbunarchivechunk command that uses processing real threads and the number of processing real threads to be used for each step of processing, see 43.1.2 Relationships among threads used by the adbunarchivechunk command.

If this option is omitted, the number of processing real threads to be used for executing the adbunarchivechunk command is determined by the adb_sql_exe_max_rthd_num operand in the server definition. The following table shows the relationship between the value of this option or the adb_sql_exe_max_rthd_num operand in the server definition and the number of processing real threads used for executing the command.

Table 43‒14: Number of processing real threads used for executing the command

No.	Value in this option or in the server definition		Number of processing real threads used for executing the command
1	When this option is omitted	If the adb_sql_exe_max_rthd_num operand in the server definition is not specified	The default value of the adb_sql_exe_max_rthd_num operand in the server definition is used.
2		If 0 or 1 is specified in the adb_sql_exe_max_rthd_num operand in the server definition	--
3		If 2 or a greater value is specified for the adb_sql_exe_max_rthd_num operand in the server definition	The value specified for the adb_sql_exe_max_rthd_num operand in the server definition is used.
4	If 2 or a greater value is specified in this option		The value specified in this option is used.

Legend:

--: The adbunarchivechunk command results in an error.

Note

For details about the adb_sql_exe_max_rthd_num operand in the server definition, see Operands related to performance (set format) in the HADB Setup and Operation Guide.

● adb_unarcv_read_size = buffer-size

~<integer>((32 to 51,200))<<1,024>> (kilobytes)

The buffer size used for the read processing of archive files is specified in kilobytes.

● adb_unarcv_buff_blk_num = number-of-buffer-blocks-for-unarchiving-chunks

~<integer>((5 to 4,096))<<64>>

Specifies the number of buffer blocks to be used for chunk unarchive processing.

There is generally no problem with using the default values, but increasing the value specified for this option might improve the performance of chunk unarchive processing.

● adb_unarcv_sort_buff_size = sort-buffer-size

~<integer>((1 to 2,048))<<256>> (megabytes)

Consider specifying this option when B-tree or text indexes are defined for the table to be processed.

Specify the size (in megabytes) of the sort buffer to be used for creating B-tree and text indexes. Specify a large value if there is sufficient memory. Better performance can be expected as this option's value becomes larger.

● adb_unarcv_dividx_rd_buff_size = B-tree-and-text-index-input-buffer-size

~<integer>((32 to 51,200))<<1,024>> (kilobytes)

Consider specifying this option if B-tree or text indexes are defined for the table to be processed.

Specify the size (in kilobytes) of the input buffer to be used for creating B-tree and text indexes. Specify a large value if there is sufficient memory. Better performance can be expected as this option's value becomes larger.

● adb_unarcv_dividx_wt_buff_size = B-tree-and-text-index-output-buffer-size

~<integer>((32 to 51,200))<<1,024>> (kilobytes)

Consider specifying this option if B-tree or text indexes are defined for the table to be processed.

Specify the size (in kilobytes) of the output buffer to be used for creating B-tree and text indexes. Specify a large value if there is sufficient memory. Better performance can be expected as this option's value becomes larger.

● adb_unarcv_txt_buff_size = buffer-size-for-creating-text-indexes

~<integer>((1 to 2,048))<<256>> (megabytes)

Consider specifying this option if text indexes are defined for the table to be processed.

Specify the size (in megabytes) of the buffer to be used for creating text indexes.

Increasing the value specified for this option often improves performance. However, the amount of buffer memory specified by this option will be used for all processing real threads on which text indexes will be built. Therefore, be careful when you increase the value specified for this option.

● adb_unarcv_decompress_buff_size = buffer-size-for-decompressing-archive-files

~<integer>((32 to 51,200))<<1,024>> (kilobytes)

Specify the size (in kilobytes) of the buffer used for decompressing archive file data.

When archive file data is decompressed, only the buffer amount specified in this option is used.

Use the value specified in the unarchive chunk option adb_unarcv_read_size as a guideline for specifying this option.

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