Stream computing error: A table cannot contain duplicate column names

Question

When creating a sessionWindowEngine, the server reported an error: "A table can't contain duplicate column names." However, both my input and output tables are properly defined and do not contain duplicate column names. What is the reason for this error, and how can I modify the script to execute the code correctly?

The definition of the input table is as follows:

ofpanel_colnames = [
"TimeStamp_1",
'ID_1', 'UpperLimit_1', 'LowerLimit_1',
'PreOpenInt_1',
'OpenPrice_1', 'HighPrice_1', 'LowPrice_1', 'LastPrice_1',
'BidPrice_1', 'BidVol_1', 'AskPrice_1', 'AskVol_1',
'Volume_1', 'Amount_1', 'OpenInt_1',
'ClosePrice_1', 'SettlePrice_1',
'ReceiveTime_1',
'UnderlyingID',
"TimeStamp_2",
'ID_2', 'UpperLimit_2', 'LowerLimit_2',
'BidPrice_2', 'BidVol_2', 'AskPrice_2', 'AskVol_2',
'ReceiveTime_2'
]
ofpanel_colTypes = [
TIMESTAMP,
SYMBOL, DOUBLE, DOUBLE,
DOUBLE,
DOUBLE, DOUBLE, DOUBLE, DOUBLE,
DOUBLE, INT, DOUBLE, INT,
INT, DOUBLE, DOUBLE,
DOUBLE, DOUBLE,
NANOTIMESTAMP,
STRING,
TIMESTAMP,
SYMBOL, DOUBLE, DOUBLE,
DOUBLE, INT, DOUBLE, INT,
NANOTIMESTAMP
]
share streamTable(1:0, ofpanel_colnames, ofpanel_colTypes ) as ofPanel_stream

The output table is defined as follows:

try{dropStreamTable("SampleStream")}catch(ex){print(ex)}
share streamTable(
 1:0,
 ["LogTime","InstrumentID","TimeStamp_1","ID_1","UpperLimit_1","LowerLimit_1","PreOpenInt_1"],
 [TIMESTAMP,STRING,TIMESTAMP,STRING,DOUBLE, DOUBLE, INT]
) as SampleStream

The engine creation script is as follows:

try{dropStreamEngine(name="DataProcessor")}catch(ex){print(ex)}
engine_ = createSessionWindowEngine(
 name = 'DataProcessor', 
 sessionGap = 30*1000, // 30s response window
 metrics=<[
 last(TimeStamp_1),
 last(ID_1),
 last(UpperLimit_1),
 last(LowerLimit_1),
 last(PreOpenInt_1)
 ]>, 
 dummyTable = ofPanel_stream, 
 outputTable = SampleStream, 
 useSystemTime=true, 
 keyColumn = `ID_1,
 useSessionStartTime=true
)

The definition of the input table is as follows:

ofpanel_colnames = [
 "TimeStamp_1",
 'ID_1', 'UpperLimit_1', 'LowerLimit_1',
 'PreOpenInt_1',
 'OpenPrice_1', 'HighPrice_1', 'LowPrice_1', 'LastPrice_1',
 'BidPrice_1', 'BidVol_1', 'AskPrice_1', 'AskVol_1',
 'Volume_1', 'Amount_1', 'OpenInt_1',
 'ClosePrice_1', 'SettlePrice_1',
 'ReceiveTime_1',
 'UnderlyingID',
 "TimeStamp_2",
 'ID_2', 'UpperLimit_2', 'LowerLimit_2',
 'BidPrice_2', 'BidVol_2', 'AskPrice_2', 'AskVol_2',
 'ReceiveTime_2'
]
ofpanel_colTypes = [
 TIMESTAMP, 
 SYMBOL, DOUBLE, DOUBLE, 
 DOUBLE, 
 DOUBLE, DOUBLE, DOUBLE, DOUBLE, 
 DOUBLE, INT, DOUBLE, INT, 
 INT, DOUBLE, DOUBLE, 
 DOUBLE, DOUBLE,
 NANOTIMESTAMP,
 STRING,
 TIMESTAMP, 
 SYMBOL, DOUBLE, DOUBLE, 
 DOUBLE, INT, DOUBLE, INT, 
 NANOTIMESTAMP
]
share streamTable(1:0, ofpanel_colnames, ofpanel_colTypes ) as ofPanel_stream

The output table is defined as follows:

try{dropStreamTable("SampleStream")}catch(ex){print(ex)}
share streamTable(
 1:0,
 ["LogTime","InstrumentID","TimeStamp_1","ID_1","UpperLimit_1","LowerLimit_1","PreOpenInt_1"],
 [TIMESTAMP,STRING,TIMESTAMP,STRING,DOUBLE, DOUBLE, INT]
) as SampleStream

The engine creation script is as follows:

try{dropStreamEngine(name="DataProcessor")}catch(ex){print(ex)}
engine_ = createSessionWindowEngine(
 name = 'DataProcessor', 
 sessionGap = 30*1000, // 30s response window
 metrics=<[
 last(TimeStamp_1),
 last(ID_1),
 last(UpperLimit_1),
 last(LowerLimit_1),
 last(PreOpenInt_1)
 ]>, 
 dummyTable = ofPanel_stream, 
 outputTable = SampleStream, 
 useSystemTime=true, 
 keyColumn = `ID_1,
 useSessionStartTime=true
)

• saki: Consider removing last(ID_1) from the metrics. Since ID_1 is specified as the keyColumn for grouping, including it in the metrics calculation might cause unexpected behavior.