bi技术主题的文章列表，还有bi技术的技术要点_第2页

hadoop中combiner是什么

Combiner（合并器）在Hadoop中，Combiner（合并器）是一个可选的阶段，用于优化MapReduce任务的性能。它是在Map阶段输出之后、规约（reduction）之前执行的。Combiner的作用是在Map任务的本地节点上对Map阶段的输出进行局部聚合。它接收Map任务输出的键值对，并将具有相同键的键值...

开发笔记 ·2024-01-23

java技术栈有哪些

一、消息队列一个大型的分布式系统，通常都会异步化，走消息总线。消息队列作为最主要的基础组件，在整个体系架构中，有着及其重要的作用。kafka是目前最常用的消息队列，尤其是在大数据方面，有着极高的吞吐量。而rocketmq和rabbitmq，都是电信级别的消息队列，在业务上用的比较多。2019年了，不要再盯着...

开发笔记 ·2023-10-23

Reachability(判断网络是否连接)

类似于一个网络状况的探针。　　[[NSNotificationCenterdefaultCenter]addObserver:selfselector:@selector(reachabilityChanged:)name:kReachabilityChangedNotificationobject:nil];&nbs...

开发笔记 ·2023-10-12

ORA-55339: a virtual model already exists for the specified model-rulebase combination

文档解释ORA-55339:avirtualmodelalreadyexistsforthespecifiedmodel-rulebasecombinationCause:Avirtualmodelwithidenticalcomponentswasalreadypresent.Action:Chooseadiffer...

IT技术学习 ·2023-07-28

ORA-24940: invalid combination of string namespace, string presentation and string receive protocol

文档解释ORA-24940:invalidcombinationofstringnamespace,stringpresentationandstringreceiveprotocolCause:Aninvalidcombinationofnamespace,presentationandreceiveprotocol...

IT技术学习 ·2023-07-28

ORA-19955: only one open thread is allowed to change the DBID

文档解释ORA-19955:onlyoneopenthreadisallowedtochangetheDBIDCause:Theoperationfailedbecausetherewereactivethreadsinthedatabase.Themostlikelycauseisthatthedatabasecra...

IT技术学习 ·2023-07-28

ORA-39172: Cannot remap transportable tablespace names with compatibility of string.

文档解释ORA-39172:Cannotremaptransportabletablespacenameswithcompatibilityofstring.Cause:Theuserattemptedtoremapatablespacenameinatransportabletablespacejobwhenthec...

IT技术学习 ·2023-07-28

ORA-25110: NOSORT may not be used with a bitmap index

文档解释ORA-25110:NOSORTmaynotbeusedwithabitmapindexCause:AnattemptwasmadetocreateabitmapindexusingtheNOSORToption.Action:RemoveNOSORTfromtheCREATEBITMAPINDEXstatem...

IT技术学习 ·2023-07-28

ORA-14701: partition-extended name or bind variable must be used for DMLs on tables partitioned by the System method

文档解释ORA-14701:partition-extendednameorbindvariablemustbeusedforDMLsontablespartitionedbytheSystemmethodCause:Userattemptednottousepartition-extendedsyntaxforata...

IT技术学习 ·2023-07-28

ORA-56708: Could not find any datafiles with asynchronous i/o capability

文档解释ORA-56708:Couldnotfindanydatafileswithasynchronousi/ocapabilityCause:TherearenodatafileswhichareasynchronousI/Ocapable.Action:Makesureasynchronousi/oispermi...

IT技术学习 ·2023-07-26

ORA-09708: soacon: failed to bind socket to port.

文档解释ORA-09708:soacon:failedtobindsockettoport.Cause:Thebindsystemcallfailedonthesocket.Action:CheckadditionalinformationforOSerror.Tryconnectingagain.ORA-09708:...

IT技术学习 ·2023-07-26

ORA-24369: required callbacks not registered for one or more bind handles

文档解释ORA-24369:requiredcallbacksnotregisteredforoneormorebindhandlesCause:NocallbackshavebeenregisteredforoneormoreofthebindhandleswhicharepartoftheRETURNINGclau...

IT技术学习 ·2023-07-26

ORA-09802: Conversion of binary label to string failed.

文档解释ORA-09802:Conversionofbinarylabeltostringfailed.Cause:ORACLEwasunabletoconvertabinarylabeltoastring.Action:ChecktheUNIXerrornumberforapossibleoperatingsyste...

IT技术学习 ·2023-07-26

ORA-15239: allocation unit size higher than string requires RDBMS compatibility string

文档解释ORA-15239:allocationunitsizehigherthanstringrequiresRDBMScompatibilitystringCause:TheallocationunitsizerequestedexceededthelimitimposedbytheRDBMScompatibili...

IT技术学习 ·2023-07-26

ORA-06742: TLI Driver: cannot alloc t_bind

文档解释ORA-06742:TLIDriver:cannotalloct_bindCause:TheTLIservercannotallocatespaceforitsrequestednetworkaddress.Action:Contactyourcustomersupportrepresentative.。ORA...

IT技术学习 ·2023-07-26