* may have seen a different subset of batches and we want to find the * highest memory usage for any one batch across all batches. */ if (hashstate->shared_info) { SharedHashInfo *shared_info = hashstate->shared_info; int i; for (i = 0; i < shared_info->num_workers; ++i) ...
sorts (memory): 在内存里排序。 Number of sort operations that were performed completely in memory and did not require any disk writes You cannot do much better than memory sorts, except maybe no sorts at all. Sorting is usually caused by selection criteria specifications within table join SQL ...
troubleshoot-stale-read.md troubleshoot-tidb-cluster.md troubleshoot-tidb-oom.md troubleshoot-write-conflicts.md tune-operating-system.md tune-region-performance.md tune-tikv-memory-performance.md tune-tikv-thread-performance.md two-data-centers-in-one-city-deployment.md upgrade...
Perform In memory Join(CPU) 忽略cpu的时间,则 Cost(HJ)=Read(S)+Read(B) 2. On-Disk Hash Join 根据上述的步骤描述,我们可以看出 Cost(HJ)=Cost(HJ1)+Cost(HJ2) 其中Cost(HJ1)的成本就是扫描S,B表,并将无法放在内存上的部分写回磁盘,对应前面第2步至第12步。Cost(HJ2)即为做nested-loop hash ...
Memory: 921(244/230/217) MB, straggler worker id: 72969760xxx CPU time: 149772(38159/37443/36736) ms, straggler worker id: 72969760xxx Physical read bytes: 3345(839/836/834) MB, straggler worker id: 72969760xxx Read bytes: 41787(10451/10446/10444) MB, straggler worker id: 72969760xxx ...
see current mode retrievals due to reading the data dictionary to find the extent information for a table to do a full scan (because you need the "right now" information, not the consistent read). During a modification, you will access the blocks in current mode in order to write to ...
For example, if a query shows high buffer usage, it may indicate that the query is performing a lot of disk I/O, which could be a performance bottleneck, especially if the data is not cached in memory. auto_explain.log_timing Purpose: Similar to log_analyze, this set...
0 sorts (memory) 0 sorts (disk) 8 rows processed SQL> 1.2使用SQL SQL>EXPLAIN PLAN FOR sql语句; SQL>SELECT plan_table_output FROM TABLE(DBMS_XPLAN.DISPLAY('PLAN_TABLE')); 示例: SQL>EXPLAIN PLAN FOR SELECT * FROM DAVE; 已解释。
MemoryLimitExceededException Raised when a request fails because of insufficient memory resources. The request can be retried. HTTP Status Code: 500 MissingParameterException Raised when a required parameter is missing. HTTP Status Code: 400
0 sorts (memory) 0 sorts (disk) 8 rows processed SQL> 1.2使用SQL SQL>EXPLAIN PLAN FOR sql语句; SQL>SELECT plan_table_output FROM TABLE(DBMS_XPLAN.DISPLAY('PLAN_TABLE')); 示例: SQL>EXPLAIN PLAN FOR SELECT * FROM DAVE; 已解释。