[IMPALA-6114] Incorrect type deduction causing analysis exception to be thrown

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: Impala 2.10.0, Impala 2.11.0
• Fix Version/s: Impala 2.11.0
• Component/s: Frontend
• Environment: Ubuntu 16.04, OS independent
• Epic Color: ghx-label-3
• Assignee: Zoram Thanga
• Reporter: Zoram Thanga
• Created: 26/Oct/17 23:02
• Updated: 15/Dec/17 23:47
• Resolved: 15/Dec/17 23:47

Description

The SELECT statement

SELECT DISTINCT CAST(0 AS DECIMAL(14)) AS foo, 0 AS bar FROM t;

fails with the following exception:

ERROR: AnalysisException: Possible loss of precision for target table 'default.t'.
Expression '0' (type: DECIMAL(14,0)) would need to be cast to INT for column 'bar'

The query succeeds if we remove the DISTINCT constraint.

The exception stack trace follows:

I1026 15:54:53.231101 17398 jni-util.cc:211] org.apache.impala.common.AnalysisException: Possible loss of precision for target table 'default.t'.
Expression '0' (type: DECIMAL(14,0)) would need to be cast to INT for column 'bar'
at org.apache.impala.analysis.StatementBase.checkTypeCompatibility(StatementBase.java:190)
at org.apache.impala.analysis.InsertStmt.prepareExpressions(InsertStmt.java:674)
at org.apache.impala.analysis.InsertStmt.analyze(InsertStmt.java:383)
at org.apache.impala.analysis.AnalysisContext.analyze(AnalysisContext.java:418)
at org.apache.impala.analysis.AnalysisContext.analyze(AnalysisContext.java:369)
at org.apache.impala.service.Frontend.analyzeStmt(Frontend.java:900)
at org.apache.impala.service.Frontend.createExecRequest(Frontend.java:1049)
at org.apache.impala.service.JniFrontend.createExecRequest(JniFrontend.java:156)
I1026 15:54:53.269991 17398 status.cc:122] AnalysisException: Possible loss of precision for target table 'default.t'.
Expression '0' (type: DECIMAL(14,0)) would need to be cast to INT for column 'bar'
@ 0x1598f53 impala::Status::Status()
@ 0x1993a5e impala::JniUtil::GetJniExceptionMsg()
@ 0x1843e50 impala::JniUtil::CallJniMethod<>()
@ 0x1840325 impala::Frontend::GetExecRequest()
@ 0x1860fca impala::ImpalaServer::ExecuteInternal()
@ 0x1860b12 impala::ImpalaServer::Execute()
@ 0x18cd0b6 impala::ImpalaServer::query()
@ 0x1df8ca0 beeswax::BeeswaxServiceProcessor::process_query()
@ 0x1df89ee beeswax::BeeswaxServiceProcessor::dispatchCall()
@ 0x1de11e9 impala::ImpalaServiceProcessor::dispatchCall()
@ 0x153fb5c apache::thrift::TDispatchProcessor::process()
@ 0x170eecd apache::thrift::server::TAcceptQueueServer::Task::run()
@ 0x170ada7 impala::ThriftThread::RunRunnable()
@ 0x170c4b3 boost::_mfi::mf2<>::operator()()
@ 0x170c349 boost::_bi::list3<>::operator()<>()
@ 0x170c095 boost::_bi::bind_t<>::operator()()
@ 0x170bfa8 boost::detail::function::void_function_obj_invoker0<>::invoke()
@ 0x171a89e boost::function0<>::operator()()
@ 0x19f289b impala::Thread::SuperviseThread()
@ 0x19fb42e boost::_bi::list4<>::operator()<>()
@ 0x19fb371 boost::_bi::bind_t<>::operator()()
@ 0x19fb334 boost::detail::thread_data<>::run()
@ 0x20a698a thread_proxy
@ 0x7f33eeb496ba start_thread
@ 0x7f33ee87f3dd clone

Issue Links

• relates to: IMPALA-1788 Consider replacing constant exprs with literal equivalents