MariaDB / MySQL

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1

phpMyAdmin show my DB version as: Server version: 10.0.21-MariaDB-log - openSUSE package

I have my slow query log settings as follows:

long_query_time = 0.200000
slow_query_log = 1
slow_query_log_file = /var/log/mysql/queries-slow.log
log_queries_not_using_indexes = 1

For some reason I get queries being logged are not slow enough to need to be logged. E.g. from the log:

> tail -n 100 -f /var/log/mysql/queries-slow.log|grep 'Query_time:'

Query_time: 0.000103 Lock_time: 0.000029 Rows_sent: 3 Rows_examined: 6

Query_time: 0.000441 Lock_time: 0.000083 Rows_sent: 35 Rows_examined: 70

Query_time: 0.000589 Lock_time: 0.000517 Rows_sent: 0 Rows_examined: 0

Query_time: 0.000386 Lock_time: 0.000324 Rows_sent: 0 Rows_examined: 0

Query_time: 0.000227 Lock_time: 0.000204 Rows_sent: 0 Rows_examined: 0

Query_time: 0.000436 Lock_time: 0.000360 Rows_sent: 0 Rows_examined: 0

Query_time: 0.001469 Lock_time: 0.000375 Rows_sent: 0 Rows_examined: 684

Any ideas on why these queries that are clearly quick enough to not be logged, are being logged?

Thanks!

2

No idea whether this is the answer but the MariaDB documentation says:

The log contains SQL queries that took longer than long_query_time seconds to perform, by default ten seconds, as well as queries that had to examine more than min_examined_row_limit rows. Time to acquire locks is not included in this calculation, only time to resolve the query.

Might be worth looking at min_examined_row_limit.

3

Good catch, thanks. It defaults to 0 which means you end up logging every query as far as I can tell. Kind of a silly default if you ask me.