“耳机是人类的避难所,音乐是心脏的救命丸 ”《BABYDOLL (Speed)》 02:36 “这首歌好像很容易引起一些难过的情绪 ”《Glimpse of Us》 03:52 “这首歌完美诠释了我对起床的感觉”《Just the Same》 03:32 “这歌给人一种想无限循环的感觉 ”《Loop》 03:11 “这首开学一定推给同学 ”《Remedy》 03:...
按照官方文档的说法: ● If the index is a covering index for the queries and can be used to satisfy all data required from the table, only the index tree is scanned. In this case, the Extracolumn says Using index. An index-only scan usually is faster than ALL because the size of the...
The 'do-while' loop can be implemented (in C) as: inti=5; do { printf("%d",i); i--; }while(i>=0); where 'i' is the loop variable. Answer and Explanation:1 Both for loop and while loop can run multiple statements in successive repetition efficiently. ...
mysql>USEstatistics;mysql>EXPLAINFORMAT=TREEFORSCHEMAcustomer1SELECTname,quantityFROMordersJOINitemsONorders.item_id=items.id;->Nested loop innerjoin(cost=2.3rows=5)->Table scan onitems(cost=0.55rows=3)->Index lookup on orders usingfk_item_id(item_id=items.id)(cost=0.472rows=1.67) 这对于大多...
I don't fully understand this for loop, if someone could give me some clarification, that would be great! I think it works this way: for(leti=0;// You create the variable i in the for loop.i<myList.length;// if the variable i is less than myList.lengthi+=1)// add 1 to i...
32 Using index for skip scan 表示使用了Skip Scan。详见Skip Scan Range Access Method 33 Using join buffer (Block Nested Loop), Using join buffer (Batched Key Access) 使用Block Nested Loop或Batched Key Access算法提高join的性能。详见https://www.cnblogs.com/chenpingzhao/p/6720531.html ...
innovation OF THE MONTH In a genre consumed by propulsion explainers and grandiose quests, Charlie Stross has a talent for creating loopily appealing science fiction plots out of corporate and market interactions. Empire games National Oceanic and Atmospheric Administration (NOAA) educational resources ...
execution info 信息除了基本的 time 和loop 信息外,还包含算子特有的执行信息,主要包含了该算子发送 RPC 请求的耗时信息以及其他步骤的耗时。 Point_Get Point_Get 算子可能包含以下执行信息: Get:{num_rpc:1, total_time:697.051µs}:向 TiKV 发送 Get 类型的 RPC 请求的数量 (num_rpc) 和所有 RPC 请...
subqueryN: The row refers to the result of a materialized subquery for the row with an id value of N. partitions (JSON name: partitions) 分区中的记录将被查询相匹配。显示此列仅在使用分区关键字。该值为NULL对于非分区表。 type (JSON name: access_type) ...
FORMAT=JSON SELECT * FROM s1 INNER JOIN s2 ON s1.key1 = s2.key2 WHERE s1.common_field ='a'\G;***1. row ***EXPLAIN:{"query_block": {"select_id":1,"cost_info": {"query_cost":"1360.07"},"nested_loop": [ {"table": {"table_name":"s1","access_type":"ALL","possible_k...