版本
4.0.11
3pd+3tidb-server 三台主机混合部署
3tikv 三台主机单独部署
tikv capacity 32G
总数据容量100G
slow.log日志：
Time: 2021-06-05T16:19:53.783556576+08:00
Txn_start_ts: 425428566771499047
Conn_ID: 11957043
Query_time: 3.3727273159999998
Parse_time: 0.000025361
Compile_time: 0.000074588
Rewrite_time: 0.000014497
Prewrite_time: 3.370892345 Commit_time: 0.000878612 Get_commit_ts_time: 0.000131003 Commit_backoff_time: 2.9939999999999998 Backoff_types: [txnLock txnLock txnLock txnLock txnLock] Resolve_lock_time: 0.168004319 Write_keys: 3 Write_size: 1226 Prewrite_region: 2
DB: product
Is_internal: false
Digest: 28ba831ebb4396aeedbfb5521353e835b066f4c620a07cc8cc5be5e1f953a8e2
Num_cop_tasks: 0
Mem_max: 8641
Prepared: false
Plan_from_cache: false
Has_more_results: false
KV_total: 0.365733336
PD_total: 0.000253936
Backoff_total: 2.9939999999999998
Write_sql_response_total: 0
Succ: true
Plan_digest: 93d61d1a96f01290e4449062de22071a01b77d879ebeb77febff55170da7b968
update t1 set xxx=‘abc’ where x = ‘xyz’ and y = ‘m’;
其中 t1有300w的数据，PRIMARY KEY (x,y)
Prewrite_time: 3.370892345，这个时间这很高，有的慢查询这个值都是5秒 8秒的
请问这个怎么优化？ 有什么思路？ 谢谢！
