16.2.2 Format of index rebuild options
- Organization of this subsection
(1) Specification format
[set adb_idxrebuild_rthd_num = number-of-processing-real-threads-to-be-used-by-adbidxrebuild-command] [set adb_idxrebuild_scan_buff_size = table-data-scan-buffer-size] [set adb_idxrebuild_buff_blk_num = number-of-buffer-blocks-for-rebuilding-indexes] [set adb_idxrebuild_sort_buff_size = sort-buffer-size] [set adb_idxrebuild_dvix_rdbuff_size = B-tree-and-text-index-input-buffer-size] [set adb_idxrebuild_dvix_wtbuff_size = B-tree-and-text-index-output-buffer-size] [set adb_idxrebuild_txt_buff_size = text-index-creation-buffer-size]
The specification rules for these index rebuild options are the same as for the server definition. For details about the syntax rules for the server definition, see the topic Syntax rules for the server definition in the HADB Setup and Operation Guide.
(2) Explanation of specification format
- • adb_idxrebuild_rthd_num = number-of-processing-real-threads-to-be-used-by-adbidxrebuild-command
-
~<integer>((3 to 4,096))
Specifies the number of processing real threads to be used for executing the adbidxrebuild command.
Specification of this option is recommended. The adbidxrebuild 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 adbidxrebuild command. For details about the processing of the adbidxrebuild command that uses processing real threads and the number of processing real threads to be used for each step, see 16.1.4 Relationships among threads used by the adbidxrebuild command.
If this option is omitted, the number of processing real threads to be used for executing the adbidxrebuild 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 16‒1: 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 a value in the range from 0 to 2 is specified in the adb_sql_exe_max_rthd_num operand in the server definition
--
3
If 3 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 3 or a greater value is specified in this option
The value specified in this option is used.
- Legend:
-
--: The adbidxrebuild 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_idxrebuild_scan_buff_size = table-data-scan-buffer-size
-
~<integer>((1 to 2,048))<<8>> (megabytes)
Specifies the size (in megabytes) of the buffer to be used for retaining table data retrieval results. A larger value can reduce overhead in retrieving table data.
As a guideline, specify the value obtained from the following formula:
- Formula
-
Key length of the B-tree indexes to be rebuilt × 100,000
For details about how to determine the key length of a B-tree index, see Determining the key length (KEYSZ) of a B-tree index in Estimating the size of the data DB area in Designing a Database in the HADB Setup and Operation Guide.
- • adb_idxrebuild_buff_blk_num = number-of-buffer-blocks-for-rebuilding-indexes
-
~<integer>((5 to 4,096))<<64>>
Specifies the number of buffer blocks to be used for index rebuild processing. You can use the default value, but a larger value might improve the speed of index rebuild processing.
- • adb_idxrebuild_sort_buff_size = sort-buffer-size
-
~<integer>((1 to 2,048))<<256>> (megabytes)
Consider specifying this option when you rebuild B-tree or text indexes.
Specifies the size (in megabytes) of the sort buffer to be used for building 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_idxrebuild_dvix_rdbuff_size = B-tree-and-text-index-input-buffer-size
-
~<integer>((32 to 51,200))<<1,024>> (kilobytes)
Consider specifying this option when you rebuild B-tree or text indexes.
Specifies the size (in kilobytes) of the input buffer to be used for building 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_idxrebuild_dvix_wtbuff_size = B-tree-and-text-index-output-buffer-size
-
~<integer>((32 to 51,200))<<1,024>> (kilobytes)
Consider specifying this option when you rebuild B-tree or text indexes.
Specifies the size (in kilobytes) of the output buffer to be used for building 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_idxrebuild_txt_buff_size = text-index-creation-buffer-size
-
~<integer>((1 to 2,048))<<256>> (megabytes)
Consider specifying this option when you rebuild text indexes.
Specifies the size (in megabytes) of the buffer to be used for building 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.