另外你这个是olap的场景吗? 之前在什么系统里,需要多长时间?
之前在kylin,用kylin sql查预计算的结果,是8s。然后把kylin预计算的结果导入到tidb, 做相同的sql查询12s
select @@tidb_index_lookup_concurrency; select @@tidb_index_lookup_size;
上面两个变量的值是多少?都改大后再执行试试看有没有效果
select @@tidb_hashagg_final_concurrency; select @@tidb_hashagg_partial_concurrency;
还有这两个变量,把值调大后再执行试试?
请参考同事的建议,试试这些参数, 另外对于你这种olap的场景,请参考下tispark,和你的场景应该更加接近.
https://pingcap.com/docs-cn/dev/reference/tispark/#tispark-用户指南
您好,四个参数之前和官网上的默认值一样,我刚刚都调大了,试了查询速度没有提升,我设置的值
select @@tidb_index_lookup_concurrency; select @@tidb_index_lookup_size;select @@tidb_hashagg_final_concurrency; select @@tidb_hashagg_partial_concurrency;
+---------------------------------+
| @@tidb_index_lookup_concurrency |
+---------------------------------+
| 15 |
+---------------------------------+
1 row in set (0.00 sec)
+--------------------------+
| @@tidb_index_lookup_size |
+--------------------------+
| 400000 |
+--------------------------+
1 row in set (0.00 sec)
+----------------------------------+
| @@tidb_hashagg_final_concurrency |
+----------------------------------+
| 10 |
+----------------------------------+
1 row in set (0.00 sec)
+------------------------------------+
| @@tidb_hashagg_partial_concurrency |
+------------------------------------+
| 20 |
+------------------------------------+
1 row in set (0.00 sec)
嗯,我待会试试
楼主你好我也在调研,我们的规模大概是百亿级别,你这个是15亿规模,而且用到了索引,看了下12s的查询返回。 请问目前有别的办法加速查询时间吗?
另外楼主说了集群资源是充足的,是指很多机器在执行sql时空闲?