7.2.6 Operands related to range indexes (set format)
- [40] adb_sql_rngidx_preread ={ALL|NO|range-index-name[,range-index-name]...}
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Specify the range indexes that are to be pre-read when the HADB server starts. For details about pre-reading of range indexes, see 5.5.3 Pre-reading of range indexes.
- ALL:
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Pre-reads all range indexes.
- NO:
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Does not pre-read any range indexes.
- range-index-name:
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~<character string> ((1 to 205 bytes))
Specify the names of range indexes that are to be pre-read. You can specify up to 8,192 range index names. Range indexes are pre-read in the order in which they are specified here.
- Important
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You must specify a range index name in the format schema-name.index-identifier. You cannot omit the schema name.
Example: \"ADBUSER01\".\"RINDX01\"
Notes:
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To pre-read range indexes, you must specify the adbbuff operand's -a option (number of pages in the global buffer dedicated to range indexes). Therefore, when allocating a global buffer to the DB area that stores range indexes to be pre-read, you must specify the -a option.
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When range indexes are pre-read, multiple pages are read based on a single page request. Consequently, in the global buffer statistical information that is output when the adbstat command is executed, the following two types of information might not match each other in some cases:
• DBbuff_page_rng_request_cnt (number of requests for pages in the range index buffer)
• DBbuff_page_rng_pagein_cnt (number of times pagein occurs in the range index buffer)
For details about the adbstat command, see adbstat (Perform Statistical Analysis of the HADB Server) in the manual HADB Command Reference.
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If the number of pages specified by the adbbuff operand's -a option become full while range indexes are being pre-read, only some of the range indexes will be in pre-read status.
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Range indexes in unfinished status cannot be pre-read.
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If a specified range index name contains a syntax error, that range index is not pre-read. Other range indexes are pre-read.