QUALIFY
SELECT语句的子句按如下所示的顺序执行：FROM WHERE GROUP BY HAVING WINDOW QUALIFY DISTINCT ORDER BY LIMIT 注意事项 QUALIFY语法需要查询语句里面至少包含一个Window函数，在没有Window函数的情况下使用QUALIFY语法会报错：FAILED:ODPS...
QUALIFY
MaxCompute支持使用QUALIFY语法根据您指定的过滤条件过滤窗（Window）函数的结果，QUALIFY语法过滤Window函数数据类似于HAVING语法处理经过聚合函数和GROUP BY后的数据。本文为您介绍QUALIFY语法和使用示例。功能简介 一个典型的查询语句的...
参数调优建议
现象：数据库中有大量的连接状态为 checking query cache for query、Waiting for query cache lock、storing result in query cache。修改建议：RDS默认是关闭query cache功能的，如果您的实例打开了query cache，当出现上述情况后可以...
数据倾斜调优
具体可以参考如下代码示例：SELECT/*+MAPJOIN(t2)*/eleme_uid,.FROM(SELECT eleme_uid,.FROM<viewtable>WHERE eleme_uid=)t1 LEFT JOIN(SELECT eleme_uid,.FROM<customertable>WHERE eleme_uid=)t2 on t1.eleme_uid=t2.eleme_uid UNION ALL...
SQL基本语法
name ON join_condition][WHERE search_condition][GROUP BY column1,column2,.][HAVING search_condition][ORDER BY column1[ASC|DESC],column2[ASC|DESC],.][LIMIT number_of_rows OFFSET start_row]SQL关键字列表 SELECT：指定要检索的...
Tekton最佳实践
you may not use this file except in compliance with the License.#You may obtain a copy of the License at#https://www.apache.org/licenses/LICENSE-2.0 # # Unless requiredby applicable law or agreed to in writing,software#...
Pig作业配置
Use the GROUP command to group records by n-gram only.-Each group now corresponds to a distinct n-gram and has the count for each hour.uniq_frequency1=GROUP hour_frequency2 BY group:ngram;For each group,identify the hour ...
Pig开发手册
Use the GROUP command to group records by n-gram only.-Each group now corresponds to a distinct n-gram and has the count for each hour.uniq_frequency1=GROUP hour_frequency2 BY group:ngram;For each group,identify the hour ...
锁以及排查锁
2.0及其以上版本 select query,state,query_id,transaction_id,pid,wait_event_type,wait_event,running_info,extend_info FROM hg_stat_activity where query_id=200640xxxx;返回结果-+-query|drop table test_order_table1;state|active ...
GetLogs-查询日志库日志
status:401|SELECT remote_addr,COUNT(*)as pv GROUP by remote_addr ORDER by pv desc limit 5 topic string 否 日志主题。默认值为双引号（""）。更多信息，请参见 日志主题（Topic）。topic line long 否 仅当 query 参数为查询语句时，...
PolarDB处理TPC-H查询的挑战和机遇
除了SQL Server和DB2这种成熟的商业数据库，能对各类group by的唯一值个数做较为精准估计的数据库应该很少。但可以在满足特定条件时作出准确估计，从而利于应用这种优化。例如MySQL，在group by key上有index时，可以针对key prefix有较为...
alicloud_dcdn_waf_rules
types-The type of the regular expression.If the value of the tags field contains waf_group,you can specify this field.remote_addr-Filter by IP address.waf_group_ids-The id of the waf rule group.effect-The effective range ...
物化视图操作
key|value|ds|+-+-+-+|1|10|1|+-+-+-+-示例2：创建带有聚簇属性的非分区物化视图 create materialized view mf_mv2 lifecycle 7 clustered by(key)sorted by(value)into 1024 buckets as select t1.id as key,t1.value as value,t1.ds as ...
Salesforce on Alibaba Cloud 产品服务协议-V1.3
This Agreement commences on the date of signature by both Parties,and will be valid until all subscriptions hereunder have expired or have been terminated.The term of the service equivalent to the"term of subscription"in ...
SQL诊断
column"xxx"must appear in the GROUP BY clause or be used in an aggregate function 重新检查SQL语法，聚合函数的字段需要包含在group by内。ERRCODE_INVALID_TRANSACTION_STATE Usage Problem 非法的事务状态。涉及事务的相关操作非法...
性能白皮书
either version 2 of the License,or-(at your option)any later version.-This program is distributed in the hope that it will be useful,-but WITHOUT ANY WARRANTY;without even the implied warranty of-MERCHANTABILITY or FITNESS...
INSERT
insert into select：INSERT INTO test2 SELECT*FROM test1;技术原理 Hologres表的存储结构分为行存、列存和行列共存，但三者的写入原理一致。如下图所示，INSERT是以Append Only的方式写入WAL，并实时更新到内存表（MemTable），保证数据...
alicloud_ecs_disks
This data source provides the Ecs Disks of the current Alibaba Cloud user.->NOTE:Available in v1.122.0+.Example Usage Basic Usage data"alicloud_ecs_disks""example"{ ids=["d-artgdsvdvxxxx"]name_regex="tf-test"} output"first...
WLM
wlm add_rule name=testRule2 type=query action=ADD_PROPERTIES attrs='{"add_prop":{"query_priority":"low"}}' predicate='user=test&ip in 10.10.10.10,192.168.0.1,192.0.2.1';返回结果如下：+-+|result|+-+|insert rule 'testRule2' ...
配置工作负载管理规则
wlm add_rule name=testRule2 type=query action=ADD_PROPERTIES attrs='{"add_prop":{"query_priority":"low"}}' predicate='user=test&ip in 10.10.10.10,192.168.0.1,192.0.2.1';返回结果如下：+-+|result|+-+|insert rule 'testRule2' ...
OOM常见问题排查指南
OOM（Out of Memory）描述的是Query的内存消耗超出了系统当前的供给，系统做出的一种异常提示。本文将会为您介绍Hologres中出现OOM情况的原因及对应处理方法。产生OOM的基本原因 有的系统在内存资源不足时会采用磁盘缓存的方式进行算子降级...
alicloud_kvstore_instances
The alicloud_kvstore_instances data source provides a collection of kvstore instances available in Alicloud account.Filters support regular expression for the instance name,searches by tags,and other filters which are ...
Explain和Explain Analyze
quantity)as avg_qty,avg(l_extendedprice)as avg_price,avg(l_discount)as avg_disc,count(*)as count_order from lineitem where l_shipdate<= date '1998-12-01' - interval '120' daygroup by l_returnflag,l_linestatus order by l_...
Dataphin中ClickHouse数据源DELETE准备语句执行报错
Copyright(C)2019-2029,Alibaba Group.All Rights Reserved.Dlink command:java-server-Xms2048m-Xmx2048m-XX:+HeapDumpOnOutOfMemoryError-XX:HeapDumpPath=dataphin/dlink/log-Xmx1024m-Xms1024m-Dloglevel=info-Dfile.encoding=UTF-8-...
alicloud_dcdn_waf_rule
when waf_group appears in tags,this value can be filled in,and only one list of six digits in string format can appear with regultypes.regular_types-(Optional)Regular rule type,when waf_group appears in tags,this value can...
alicloud_redis_tair_instance
slave architecture instance with or without passing 1.storage_performance_level-(Optional,ForceNew,Available since v1.211.1)The storage type.The value range is[PL1,PL2,and PL3].The default value is PL1.When the value of ...
表批读写
SQL AS OF 语法%sql SELECT*FROM events TIMESTAMP AS OF timestamp_expression SELECT*FROM events VERSION AS OF version 说明 timestamp_expression为实际的时间，你可以通过 DESCRIBE HISTORY events查看表的历史版本 table_identifier...
SELECT INTO
语法[WITH[RECURSIVE]with_query[,.]]SELECT[ALL|DISTINCT[ON(expression[,.])]]*|expression[[AS]output_name][,.]INTO[TEMPORARY|TEMP|UNLOGGED][TABLE]new_table[FROM from_item[,.]][WHERE condition][GROUP BY expression[,.]][HAVING...
基于pgpool实现读写分离
修改配置文件sysctl.conf，命令如下：sudo vi/etc/sysctl.conf#add by digoal.zhou fs.aio-max-nr=1048576 fs.file-max=76724600#可选：kernel.core_pattern=data01/corefiles/core_%e_%u_%t_%s.%p#data01/corefiles 提前建好，权限777，...
alicloud_ehpc_cluster
HPC client.By default,the parameter is set to the latest version number.cluster_name-(Required)The name of the cluster.The name must be 2 to 64 characters in length.cluster_version-(Optional)The version of the cluster....
函数
SHA()Calculate an SHA-1 160-bit checksum SHA2()Calculate an SHA-2 checksum VALIDATE_PASSWORD_STRENGTH()Determine strength of password 其他函数 ANY_VALUE()Suppress ONLY_FULL_GROUP_BY value rejection DEFAULT()Return the ...
alicloud_wafv3_domain
true:indicates that HTTPS forced redirection is enabled. - false: indicates that HTTPS forced redirection is not enabled. http2_enabled -(Optional)Whether to turn on http2. This parameter is used only if the valueof ...
可观测监控 Prometheus 版开源一致性认证
demo_memory_usage_bytes PASS(1*2+4/6-(10%7)^2)*demo_memory_usage_bytes PASS(1*2+4/6-(10%7)^2)/demo_memory_usage_bytes PASS(1*2+4/6-(10%7)^2)%demo_memory_usage_bytes PASS(1*2+4/6-(10%7)^2)^demo_memory_usage_bytes PASS(1*2+4...
可观测监控 Prometheus 版开源一致性认证
demo_memory_usage_bytes PASS(1*2+4/6-(10%7)^2)*demo_memory_usage_bytes PASS(1*2+4/6-(10%7)^2)/demo_memory_usage_bytes PASS(1*2+4/6-(10%7)^2)%demo_memory_usage_bytes PASS(1*2+4/6-(10%7)^2)^demo_memory_usage_bytes PASS(1*2+4...
SelectObject
true</SkipPartialDataRecord><MaxSkippedRecordsAllowed>max allowed number of records skipped</MaxSkippedRecordsAllowed></Options>请求元素 名称 类型 描述 SelectRequest 容器 保存Select请求的容器 子节点：Expression，...
创建GLOBAL INDEX
显示结果如下：QUERY PLAN-Seq Scan on tbl1 b SubPlan 1->Global Partitioned Index Scan(3/3)using idx_global_tprt on tprt a Index Cond:(col2=b.col1)(4 rows)select(select col1 from tprt a where a.col2=b.col1)as x,b.col1 from ...
自助健康检查常用命令
query_date,count(*)from hologres.query_log where query_date>to_char(current_date-interval'7 days','YYYYMMDD')and command_tag in('SELECT','INSERT','UPDATE','DELETE')group by datname,query_date order by datname,query_date ...
1055(42000):SELECT list is not in GROUP BY clause ...
问题现象 在执行MySQL命令进行查询时，提示如下错误：1055(42000):SELECT list is not in GROUP BY clause and contains nonaggregated column 可能原因 该报错可能由以下两种原因引入：原因一：用户修改了sql_mode参数，加上了ONLY_FULL_...
1055(42000):SELECT list is not in GROUP BY clause ...
问题现象 在执行MySQL命令进行查询时，提示如下错误：1055(42000):SELECT list is not in GROUP BY clause and contains nonaggregated column 可能原因 该报错可能由以下两种原因引入：原因一：用户修改了sql_mode参数，加上了ONLY_FULL_...
SELECT语法
SELECT用于返回表和用户定义的函数中的行，具体语法如下[WITH with_subquery[,.]]SELECT[[ALL|DISTINCT]|select_expr[AS output_name][,.]][FROM table_reference[,.]][WHERE condition][GROUP BY expression[,.]][HAVING condition][{ ...
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