Re: [Maria-developers] da70f190279: MDEV-25985 Spider handle ">=" as ">" in some cases
Hi, Nayuta! The code change is good, no comments about it at all. But why did you create a new suite spider/bugfix and all those files in it? I know that some later spider version has it. Still, I'd expect it'd be much simpler and a smaller change to drop the test file into the exising spider suite. On Jul 12, Nayuta Yanagisawa wrote:
revision-id: da70f190279 (mariadb-10.2.39-44-gda70f190279) parent(s): 99f700a820e author: Nayuta Yanagisawa <nayuta.yanagisawa@hey.com> committer: Nayuta Yanagisawa <nayuta.yanagisawa@hey.com> timestamp: 2021-07-08 14:12:45 +0000 message:
MDEV-25985 Spider handle ">=" as ">" in some cases
The function spider_db_append_key_where_internal() converts HA_READ_AFTER_KEY to '>'. The conversion seems to be correct for single-column indexes because HA_READ_AFTER_KEY means "read the key after the provided value."
However, how about multi-column indexes? Assume that there is a multi-column index on c1 and c2 and we search with the condition 'c1 >= 100 AND c2 > 200'. The key_range.flag corresponds to the search condition could be HA_READ_AFTER_KEY. In such a case, we could not simply convert HA_READ_AFTER_KEY to '>'.
The correct conversion is to convert HA_READ_AFTER_KEY to '>' only for the last column in key_part_map and to convert HA_READ_AFTER_KEY to '>=' for the other column.
The similar discussion also applies to the conversion from key_range.flag to a sign of inequality.
Regards, Sergei VP of MariaDB Server Engineering and security@mariadb.org
Hi Sergei, Thank you for your review. I just created the spider/bugfix directory for the consistency with the later versions. However, I do not have a strong opinion on it and your point sounds reasonable. So, I'll push the revised version again as such. Regard, Nayuta On July 13, 2021, Sergei Golubchik <serg@mariadb.org> wrote:
Hi, Nayuta!
The code change is good, no comments about it at all.
But why did you create a new suite spider/bugfix and all those files in it? I know that some later spider version has it. Still, I'd expect it'd be much simpler and a smaller change to drop the test file into the exising spider suite.
On Jul 12, Nayuta Yanagisawa wrote:
revision-id: da70f190279 (mariadb-10.2.39-44-gda70f190279) parent(s): 99f700a820e author: Nayuta Yanagisawa <nayuta.yanagisawa@hey.com> committer: Nayuta Yanagisawa <nayuta.yanagisawa@hey.com> timestamp: 2021-07-08 14:12:45 +0000 message: MDEV-25985 Spider handle ">=" as ">" in some cases The function spider_db_append_key_where_internal() converts HA_READ_AFTER_KEY to '>'. The conversion seems to be correct for single-column indexes because HA_READ_AFTER_KEY means "read the key after the provided value." However, how about multi-column indexes? Assume that there is a multi-column index on c1 and c2 and we search with the condition 'c1 >= 100 AND c2 > 200'. The key_range.flag corresponds to the search condition could be HA_READ_AFTER_KEY. In such a case, we could not simply convert HA_READ_AFTER_KEY to '>'. The correct conversion is to convert HA_READ_AFTER_KEY to '>' only for the last column in key_part_map and to convert HA_READ_AFTER_KEY to '>=' for the other column. The similar discussion also applies to the conversion from key_range.flag to a sign of inequality. Regards, Sergei VP of MariaDB Server Engineering and security@mariadb.org
participants (2)
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Nayuta Yanagisawa -
Sergei Golubchik