insert into select 使用上旁路导入比不使用执行时间变慢了2.4倍

dbkid · 2025 年1 月 21 日 18:58

【使用环境】测试环境
【 OB or 其他组件】OB
【使用版本】v4.3.5.0
【问题描述】insert into … select … 语句使用上旁路导入比不使用性能下降了 50%，求问原因
【复现路径】问题出现前后相关操作

部署集群，选用 OLAP 场景创建租户

obd cluster tenant create obtest -n test --max-cpu=28 --memory-size=98G --zone-list=zone1,zone2,zone3 --primary-zone=RANDOM \
--locality=F@zone1,F@zone2,F@zone3 --charset=utf8 -s 'ob_tcp_invited_nodes="%"' --optimize=olap

调整配置参数

set global parallel_servers_target = 560; 
ALTER SYSTEM SET default_table_store_format = 'row';
SET GLOBAL parallel_degree_policy = MANUAL;

用 sysbench 准备3个表数据，每个表1000万行
create table tmp1 like sbtest1;
ALTER TABLE tmp1 MODIFY id int(11) NOT NULL; – 删除目标表主键自增属性
分别使用旁路导入和传统路径导入插入数据，发现使用旁路导入执行时间变慢了2.4倍。

mysql> insert /*+ enable_parallel_dml parallel(16) no_direct */ into tmp1 select * from sbtest1;
Query OK, 10000000 rows affected (10.24 sec)
Records: 10000000  Duplicates: 0  Warnings: 0

mysql> truncate table tmp1;
Query OK, 0 rows affected (0.16 sec)

mysql> insert /*+ enable_parallel_dml parallel(16) DIRECT(true, 0, 'full') */ into tmp1 select * from sbtest1;
Query OK, 10000000 rows affected (24.42 sec)
Records: 10000000  Duplicates: 0  Warnings: 0

用上 NO_GATHER_OPTIMIZER_STATISTICS hint 没有区别

mysql> insert /*+ enable_parallel_dml parallel(16) DIRECT(true, 0, 'full') NO_GATHER_OPTIMIZER_STATISTICS */ into tmp1 select * from sbtest1;
Query OK, 10000000 rows affected (24.58 sec)
Records: 10000000  Duplicates: 0  Warnings: 0

mysql>  insert /*+ enable_parallel_dml parallel(16) no_direct NO_GATHER_OPTIMIZER_STATISTICS */ into tmp1 select * from sbtest1;
Query OK, 10000000 rows affected (10.45 sec)
Records: 10000000  Duplicate:: 0  Warnings: 0

执行计划：

/*+ enable_parallel_dml parallel(16) no_direct NO_GATHER_OPTIMIZER_STATISTICS */
pdml_no_direct_path_plan.log (19.0 KB)
/*+ enable_parallel_dml parallel(16) DIRECT(true, 0, 'full') NO_GATHER_OPTIMIZER_STATISTICS */
pdml_direct_path_plan.log (17.3 KB)

@论坛小助手

论坛小助手 · 2025 年1 月 21 日 18:58

推荐使用 obdiag 工具进行日志采集，以便我们分析性能下降的原因。

日志采集场景: SQL性能问题
日志采集命令: obdiag gather scene run --scene=observer.perf_sql --env “{db_connect=’-h127.0.0.1 -P2881 -utest@test -p****** -Dtest’, trace_id=‘Yxx’}”

请将采集到的日志提供给我们，以便确认问题所在。另外，为了更好地帮助您定位问题，请您提供以下信息：

旁路导入开启前后，具体的执行计划是否有变化？
是否有其他系统资源（如CPU、内存、IO）使用率的变化？
数据量和数据分布在这两次测试中是否完全一致？
是否存在锁等待或者阻塞的情况？

这些信息将有助于我们更准确地分析性能下降的原因。

附上敏捷诊断工具 obdiag 使用帮助链接

淇铭 · 2025 年1 月 22 日 11:20

可以按照小助手的提示
SQL性能收集一下
日志采集命令: obdiag gather scene run --scene=observer.perf_sql --env “{db_connect=’-h127.0.0.1 -P2881 -utest@test -p****** -Dtest’, trace_id=‘Yxx’}”

dbkid · 2025 年1 月 22 日 15:54

请问 trace_id 如何获得

论坛小助手 · 2025 年1 月 22 日 16:01

根据文档库中的信息，trace_id 是用于追踪特定 SQL 请求的唯一标识符。您可以使用以下几种方法获取 trace_id：

通过 DECODE_TRACE_ID() 函数：
您可以使用 DECODE_TRACE_ID() 函数来解析 trace_id，这将返回发起 SQL 请求的服务器 IP 和端口。例如：
```
SELECT DECODE_TRACE_ID(LAST_TRACE_ID());
```
从视图 GV$OB_SQL_AUDIT 获取：
您也可以通过查询系统视图 GV$OB_SQL_AUDIT 来获取 trace_id。这个视图包含了所有 SQL 请求的审计信息。例如：
```
SELECT trace_id FROM GV$OB_SQL_AUDIT WHERE sql_text LIKE '%您的SQL语句%' LIMIT 1;
```
在日志文件中查找：
如果您已经执行了某个 SQL 请求并且想要找到它的 trace_id，可以登录到对应的 OBServer 节点并进入日志文件所在目录，然后使用 grep 命令搜索日志文件。例如：
```
cd /home/admin/oceanbase/log
grep '您的SQL关键字' observer.log | head -n 1
```
这样可以从日志中找到包含该 SQL 关键字的日志行，并从中提取 trace_id。
设置 tracefile_identifier：
在执行 SQL 之前，可以通过设置会话级别的 tracefile_identifier 参数为一个唯一的字符串，以便更容易地在日志中识别出与该会话相关的日志条目。例如：
```
SET SESSION tracefile_identifier = 'MY_TRACE';
```
使用全链路追踪展示功能：
当通过 JDBC 或 SQL 接口连接到业务数据库时，可以设置一个与调用请求关联的 Trace ID。这个 Trace ID 随后被记录在 OceanBase 数据库的全链路追踪系统中。使用 Show Trace 命令，用户可以查询到与 Trace ID 相关的详细信息。

请根据您的具体需求选择合适的方法来获取 trace_id。如果您需要进一步的帮助，请提供更多的上下文信息。

详情请参考:

(小助手的答复已结束，如未能解决您的问题，请继续提问并等待其他同学的回复，谢谢！)

淇铭 · 2025 年1 月 22 日 16:10

–根据时间和执行语句查询trace_id
select query_sql,svr_ip,TRACE_ID,client_ip,TENANT_NAME,user_name,DB_NAME,ELAPSED_TIME,RET_CODE,FROM_UNIXTIME(ROUND(REQUEST_TIME/1000/1000),’%Y-%m-%d %H:%i:%S’) from GV$OB_SQL_AUDIT
WHERE REQUEST_TIME>=‘2024-04-05 14:34:00’ and lower(query_sql) like ‘%select%’;

dbkid · 2025 年1 月 22 日 17:02

测试数据库没有设置密码，怎么都搜集不成功了

dbkid · 2025 年1 月 22 日 18:06

搜集好了，感觉卡在了 PHY_VEC_PX_FIFO_COORD 这个算子。麻烦看看呢。

direct.tar.gz (738.0 KB)

no_direct.tar.gz (263.5 KB)

dbkid · 2025 年1 月 23 日 17:48

请问有什么发现吗？

淇铭 · 2025 年1 月 23 日 17:49

使用旁路导入的时候观察一下CPU和磁盘看看是否有瓶颈

dbkid · 2025 年1 月 23 日 18:13

没有看到有什么瓶颈。

image3636×1482 255 KB
另外没有用旁路导入的执行计划有个PHY_PX_MULTI_PART_INSERT 算子，但是旁路导入的没有，这个是符合预期的吗？

淇铭 · 2025 年1 月 24 日 10:15

没有问题这个符合预期你用下面这个方式根据下面的四个值查一下历史的两种方式执行计划
/* 也可以指定(tenant_id, svr_ip, svr_port, plan_id)四元组查询指定计划信息 */
obclient> SELECT DBMS_XPLAN.DISPLAY_CURSOR(
123,
‘all’,
‘127.0.0.1’,
2828,
1002
) FROM DUAL;

独善其身 · 2025 年1 月 24 日 10:20

助手回复的收集方法比较专业,但最好还是考虑间接方法看看能否直接使用load data工具试一下

dbkid · 2025 年2 月 17 日 18:04

麻烦再帮忙看一下

mysql> insert /*+ enable_parallel_dml parallel(16) no_direct */ into tmp1 select * from sbtest1;
Query OK, 10000000 rows affected (10.70 sec)
Records: 10000000  Duplicates: 0  Warnings: 0

mysql> SELECT DBMS_XPLAN.DISPLAY_CURSOR() FROM DUAL;
+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| DBMS_XPLAN.DISPLAY_CURSOR()                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| =================================================================================================================================
|ID|OPERATOR                             |NAME           |EST.ROWS|EST.TIME(us)|REAL.ROWS|REAL.TIME(us)|IO TIME(us)|CPU TIME(us)|
---------------------------------------------------------------------------------------------------------------------------------                                                                                                                                       [0/1860]
|0 |OPTIMIZER STATS MERGE                |               |15488844|127059135   |0        |10636392     |0          |10447       |
|1 |+-PX COORDINATOR                     |               |15488844|127018137   |0        |10636392     |8341764    |8349430     |
|2 |  +-EXCHANGE OUT DISTR               |:EX10001       |15488844|105598278   |0        |10622709     |0          |27          |
|3 |    +-INSERT                         |               |15488844|102587181   |0        |10622709     |0          |8077374     |
|4 |      +-OPTIMIZER STATS GATHER       |               |15488844|4501213     |10000000 |10579550     |0          |152286      |
|5 |        +-EXCHANGE IN DISTR          |               |15488844|4498651     |10000000 |10579550     |79842      |216653      |
|6 |          +-EXCHANGE OUT DISTR (HASH)|:EX10000       |15488844|3159910     |10000000 |10244192     |7593673    |7679067     |
|7 |            +-SUBPLAN SCAN           |ANONYMOUS_VIEW1|15488844|148813      |10000000 |10196849     |0          |1556        |
|8 |              +-PX BLOCK ITERATOR    |               |15488844|146250      |10000000 |10196849     |0          |65684       |
|9 |                +-TABLE FULL SCAN    |sbtest1        |15488844|146250      |10000000 |10196849     |0          |442752      |
=================================================================================================================================

Outputs & filters:
-------------------------------------
  0 - output(nil), filter(nil), rowset=256
  1 - output([column_conv(INT,PS:(11,0),NOT NULL,ANONYMOUS_VIEW1.id)], [column_conv(INT,PS:(11,0),NOT NULL,ANONYMOUS_VIEW1.k)], [column_conv(CHAR,utf8mb4_bin,
      length:120,NOT NULL,ANONYMOUS_VIEW1.c)], [column_conv(CHAR,utf8mb4_bin,length:60,NOT NULL,ANONYMOUS_VIEW1.pad)]), filter(nil), rowset=256
  2 - output([column_conv(INT,PS:(11,0),NOT NULL,ANONYMOUS_VIEW1.id)], [column_conv(INT,PS:(11,0),NOT NULL,ANONYMOUS_VIEW1.k)], [column_conv(CHAR,utf8mb4_bin,
      length:120,NOT NULL,ANONYMOUS_VIEW1.c)], [column_conv(CHAR,utf8mb4_bin,length:60,NOT NULL,ANONYMOUS_VIEW1.pad)]), filter(nil), rowset=256
      dop=16
  3 - output([column_conv(INT,PS:(11,0),NOT NULL,ANONYMOUS_VIEW1.id)], [column_conv(INT,PS:(11,0),NOT NULL,ANONYMOUS_VIEW1.k)], [column_conv(CHAR,utf8mb4_bin,
      length:120,NOT NULL,ANONYMOUS_VIEW1.c)], [column_conv(CHAR,utf8mb4_bin,length:60,NOT NULL,ANONYMOUS_VIEW1.pad)]), filter(nil)
      columns([{tmp1: ({tmp1: (tmp1.id, tmp1.k, tmp1.c, tmp1.pad)})}]), partitions(p0),
      column_values([column_conv(INT,PS:(11,0),NOT NULL,ANONYMOUS_VIEW1.id)], [column_conv(INT,PS:(11,0),NOT NULL,ANONYMOUS_VIEW1.k)], [column_conv(CHAR,
      utf8mb4_bin,length:120,NOT NULL,ANONYMOUS_VIEW1.c)], [column_conv(CHAR,utf8mb4_bin,length:60,NOT NULL,ANONYMOUS_VIEW1.pad)])
  4 - output([column_conv(INT,PS:(11,0),NOT NULL,ANONYMOUS_VIEW1.id)], [column_conv(INT,PS:(11,0),NOT NULL,ANONYMOUS_VIEW1.k)], [column_conv(CHAR,utf8mb4_bin,
      length:120,NOT NULL,ANONYMOUS_VIEW1.c)], [column_conv(CHAR,utf8mb4_bin,length:60,NOT NULL,ANONYMOUS_VIEW1.pad)]), filter(nil), rowset=256
  5 - output([column_conv(INT,PS:(11,0),NOT NULL,ANONYMOUS_VIEW1.id)], [ANONYMOUS_VIEW1.k], [ANONYMOUS_VIEW1.c], [ANONYMOUS_VIEW1.pad]), filter(nil), rowset=256
  6 - output([column_conv(INT,PS:(11,0),NOT NULL,ANONYMOUS_VIEW1.id)], [ANONYMOUS_VIEW1.k], [ANONYMOUS_VIEW1.c], [ANONYMOUS_VIEW1.pad]), filter(nil), rowset=256
      (#keys=1, [column_conv(INT,PS:(11,0),NOT NULL,ANONYMOUS_VIEW1.id)]), dop=16
  7 - output([ANONYMOUS_VIEW1.id], [ANONYMOUS_VIEW1.k], [ANONYMOUS_VIEW1.c], [ANONYMOUS_VIEW1.pad]), filter(nil), rowset=256
      access([ANONYMOUS_VIEW1.id], [ANONYMOUS_VIEW1.k], [ANONYMOUS_VIEW1.c], [ANONYMOUS_VIEW1.pad])
  8 - output([sbtest1.id], [sbtest1.k], [sbtest1.c], [sbtest1.pad]), filter(nil), rowset=256
  9 - output([sbtest1.id], [sbtest1.k], [sbtest1.c], [sbtest1.pad]), filter(nil), rowset=256
      access([sbtest1.id], [sbtest1.k], [sbtest1.c], [sbtest1.pad]), partitions(p0)
      is_index_back=false, is_global_index=false,
      range_key([sbtest1.id]), range(MIN ; MAX)always true

 |
+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

dbkid · 2025 年2 月 17 日 18:06

mysql> insert /*+ enable_parallel_dml parallel(16) DIRECT(true, 0, 'full') */ into tmp1 select * from sbtest1;
Query OK, 10000000 rows affected (24.00 sec)
Records: 10000000  Duplicates: 0  Warnings: 0

mysql> SELECT DBMS_XPLAN.DISPLAY_CURSOR() FROM DUAL;
+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| DBMS_XPLAN.DISPLAY_CURSOR()                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------[0/1947]-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| =============================================================================================================================
|ID|OPERATOR                         |NAME           |EST.ROWS|EST.TIME(us)|REAL.ROWS|REAL.TIME(us)|IO TIME(us)|CPU TIME(us)|
-----------------------------------------------------------------------------------------------------------------------------
|0 |PX COORDINATOR                   |               |15488844|127015574   |0        |20690388     |432178     |436237      |
|1 |+-EXCHANGE OUT DISTR             |:EX10001       |15488844|105595716   |0        |554680       |0          |11          |
|2 |  +-INSERT                       |               |15488844|102584619   |0        |554680       |0          |374867      |
|3 |    +-EXCHANGE IN DISTR          |               |15488844|4498651     |10000000 |554680       |7327       |74561       |
|4 |      +-EXCHANGE OUT DISTR (HASH)|:EX10000       |15488844|3159910     |10000000 |546276       |177504     |234791      |
|5 |        +-SUBPLAN SCAN           |ANONYMOUS_VIEW1|15488844|148813      |10000000 |546276       |0          |1303        |
|6 |          +-PX BLOCK ITERATOR    |               |15488844|146250      |10000000 |546276       |0          |54084       |
|7 |            +-TABLE FULL SCAN    |sbtest1        |15488844|146250      |10000000 |546276       |0          |286463      |
=============================================================================================================================

Outputs & filters:
-------------------------------------
  0 - output(nil), filter(nil), rowset=256
  1 - output(nil), filter(nil), rowset=256
      dop=16
  2 - output(nil), filter(nil), rowset=256
      columns([{tmp1: ({tmp1: (tmp1.id, tmp1.k, tmp1.c, tmp1.pad)})}]), partitions(p0),
      column_values([column_conv(INT,PS:(11,0),NOT NULL,ANONYMOUS_VIEW1.id)], [column_conv(INT,PS:(11,0),NOT NULL,ANONYMOUS_VIEW1.k)], [column_conv(CHAR,
      utf8mb4_bin,length:120,NOT NULL,ANONYMOUS_VIEW1.c)], [column_conv(CHAR,utf8mb4_bin,length:60,NOT NULL,ANONYMOUS_VIEW1.pad)])
  3 - output([column_conv(INT,PS:(11,0),NOT NULL,ANONYMOUS_VIEW1.id)], [ANONYMOUS_VIEW1.k], [ANONYMOUS_VIEW1.c], [ANONYMOUS_VIEW1.pad]), filter(nil), rowset=256
  4 - output([column_conv(INT,PS:(11,0),NOT NULL,ANONYMOUS_VIEW1.id)], [ANONYMOUS_VIEW1.k], [ANONYMOUS_VIEW1.c], [ANONYMOUS_VIEW1.pad]), filter(nil), rowset=256
      (#keys=1, [column_conv(INT,PS:(11,0),NOT NULL,ANONYMOUS_VIEW1.id)]), dop=16
  5 - output([ANONYMOUS_VIEW1.id], [ANONYMOUS_VIEW1.k], [ANONYMOUS_VIEW1.c], [ANONYMOUS_VIEW1.pad]), filter(nil), rowset=256
      access([ANONYMOUS_VIEW1.id], [ANONYMOUS_VIEW1.k], [ANONYMOUS_VIEW1.c], [ANONYMOUS_VIEW1.pad])
  6 - output([sbtest1.id], [sbtest1.k], [sbtest1.c], [sbtest1.pad]), filter(nil), rowset=256
  7 - output([sbtest1.id], [sbtest1.k], [sbtest1.c], [sbtest1.pad]), filter(nil), rowset=256
      access([sbtest1.id], [sbtest1.k], [sbtest1.c], [sbtest1.pad]), partitions(p0)
      is_index_back=false, is_global_index=false,
      range_key([sbtest1.id]), range(MIN ; MAX)always true

 |
+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

coolfishchen · 2025 年2 月 18 日 11:36

这是4.3.5.0的一个bug。在小数据量的情况下有两个问题：1. 写入的数据需要根据主键排序，排序的时候在小数据量的情况下只用了一个线程。2. 小数据量后台任务的采样太粗略了，导致任务划分只有一个线程在工作。这个两个问题预计在4.3.5.2解决。