从 mysql 5.5 迁移到 mariadb 10.2.13 后,我遇到了一个性能问题。包括配置在内的两台机器的大小是相同的。我们注意到某个 select 语句突然需要大约 20 秒来执行,而不是 0.5 秒。数据纯粹是从内存中读取的,因为在执行期间要测量的读取 IO 为零。将mariadb上的optimizer_switch改为mysql5.5的设置,执行计划没有改变。
mysql5.5上select的说明:
选择语句:
SELECT acmh.OBJ_VERSION,acmh.peannr,acmh.pzsrnr,xuts.ptitle,
acmh.pcategory,acmh.psalutatio,acmh.plastname,acmh.pfirstname,
acmh.pcompanyna,syoq.paddress1,syoq.pzip,syoq.pcity,syoq.pphone1,
syoq.pphone2,syoq.pphone3,syoq.pphone4,syoq.pemail,acmh.piscompany,
xuts.id
FROM catalog1.tr_table_acmh acmh,catalog1.tr_table_syoq syoq,
catalog1.tr_table_xuts xuts,catalog1.tr_table_wdvi link0,
catalog1.tr_table_wdvi acl0
WHERE acmh.id=syoq.id
AND acmh.id=xuts.id
AND syoq.id=xuts.id
AND xuts.OBJ_TYPE IN (1557)
AND ( (xuts.id=link0.pchild
AND link0.pparent='xkgrrslqkeaaaaendrxa'
AND link0.pname='folder')
and 1 = 1 )
AND xuts.pvcurrent=1
AND (acl0.pchild=xuts.pacl
AND acl0.pparent='xkgrrswxbjaaaaaaabip'
AND acl0.pvalue>=20
)
order by acmh.plastname asc,
acmh.pfirstname asc,
acmh.pcompanyna asc
LIMIT 10 OFFSET 0;
我是否缺少任何可以在 mariadb 上强制执行不同行为的开关?
最佳答案
关于mysql 5.5 到 mariadb 10.2.13 : 4000% increase in execution time for select,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/48939543/