void TimeSeries::describeParamsAndColumns(UDRInvocationInfo &info)
{
InternalColumns internalCols(info);
// create PARTITION BY output columns, one passthru column
// for every column that appears in PARTITION BY
const PartitionInfo &part = info.in().getQueryPartitioning();
int numPartCols = part.getNumEntries();
for (int pc=0; pc<numPartCols; pc++)
info.addPassThruColumns(0, part.getColumnNum(pc), part.getColumnNum(pc));
// since we work locally in a partition, set the function type
// of this TMUDF to REDUCER
info.setFuncType(UDRInvocationInfo::REDUCER);
// produce the time column, it has the same type as the
// ORDER BY column that defines the input time value
// and its name is specified by parameter 0
const TypeInfo &timeType =
info.in().getColumn(internalCols.getTimeSliceInColNum()).getType();
info.out().addColumn(ColumnInfo(info.par().getString(0).c_str(),
timeType));
// produce aggregate columns
for (int a=0; a<internalCols.getNumAggrCols(); a++)
{
TimeSeriesAggregate tsa = internalCols.getAggrColumn(a);
std::string outColName(info.par().getString(2*a + 2));
TypeInfo inColType(
info.in().getColumn(tsa.getInputColNum()).getType());
// append suffix to input column name to form the output column
// name, make those all capitals to avoid delimited identifiers
outColName += "_";
if (tsa.isFirstVal())
outColName += "F";
else
outColName += "L";
if (tsa.isConstInterpol())
outColName += "C";
else
outColName += "L";
if (tsa.isIgnoreNulls())
outColName += "I";
if (tsa.isConstInterpol())
{
// add a column with the same data type as the original
// column, but make it nullable if it isn't already
inColType.setNullable(true);
info.out().addColumn(ColumnInfo(outColName.c_str(), inColType));
}
else
// add a "DOUBLE" output column to allow interpolation
info.out().addColumn(ColumnInfo(
outColName.c_str(),
TypeInfo(TypeInfo::DOUBLE_PRECISION,
0,
true)));
}
// add formal parameters with types that match the actual ones
for (int p=0; p<info.par().getNumColumns(); p++)
{
char parName[20];
snprintf(parName, sizeof(parName), "PAR_%d", p);
info.addFormalParameter(ColumnInfo(parName,
info.par().getColumn(p).getType()));
}
}
void Sessionize::describeParamsAndColumns(UDRInvocationInfo &info)
{
// First, do some validation of the parameters and set
// PARTITION BY and ORDER BY columns
int idCol = -1;
int tsCol = -1;
// Make sure we have exactly one table-valued input, otherwise
// generate a compile error
if (info.getNumTableInputs() != 1)
throw UDRException(38000,
"%s must be called with one table-valued input",
info.getUDRName().data());
// check whether the first two arguments identify
// an arbitrary column and an exact numeric column
if (info.par().isAvailable(0))
{
const PartitionInfo &queryPartInfo = info.in().getQueryPartitioning();
PartitionInfo newPartInfo;
// This will raise an error if the column name
// specified in the first parameter doesn't exist
idCol = info.in().getColNum(info.par().getString(0));
// make sure the query didn't specify a conflicting
// PARTITION BY clause
if (queryPartInfo.getType() == PartitionInfo::PARTITION &&
(queryPartInfo.getNumEntries() != 1 ||
queryPartInfo.getColumnNum(0) != idCol))
throw UDRException(38001,
"Query PARTITION BY not compatible with id column %s",
info.par().getString(0).c_str());
// Set this user id column as the required PARTITION BY column
newPartInfo.setType(PartitionInfo::PARTITION);
newPartInfo.addEntry(idCol);
info.setChildPartitioning(0, newPartInfo);
}
else
throw UDRException(38001,"First scalar parameter must be a string constant");
// make sure the second parameter specifies the name of
// an existing input column of type exact numeric
if (info.par().isAvailable(1))
{
// This will raise an error if the column name
// specified in the second parameter doesn't exist
tsCol = info.in().getColNum(info.par().getString(1));
const TypeInfo &typ = info.in().getColumn(tsCol).getType();
const OrderInfo &queryOrderInfo = info.in().getQueryOrdering();
OrderInfo newOrderInfo;
if (typ.getSQLTypeSubClass() != TypeInfo::EXACT_NUMERIC_TYPE)
throw UDRException(38002, "Second parameter must be the name of an exact numeric column");
// check for a conflicting ORDER BY in the query
if (queryOrderInfo.getNumEntries() > 0 &&
(queryOrderInfo.getColumnNum(0) != tsCol ||
queryOrderInfo.getOrderType(0) == OrderInfo::DESCENDING))
throw UDRException(
38900,
"Query ORDER BY conflicts with specified timestamp column %s",
info.par().getString(1).c_str());
// make a new ORDER BY clause with just the timestamp column
newOrderInfo.addEntry(tsCol);
info.setChildOrdering(0, newOrderInfo);
}
else
throw UDRException(38003,"Second scalar parameter must be a string constant");
// To demonstrate state that gets passed between compiler phases and
// to avoid looking up the id column and timestamp column each time,
// store those as UDR Writer data in the UDRInvocationInfo object
/* TBD: uncomment when this is allowed
info.setUDRWriterCompileTimeData(new InternalColumns(idCol, tsCol));
*/
// Second, define the output parameters
// add the columns for session id and sequence number
// (sequence_no is a unique sequence number within the session)
info.out().addLongColumn("SESSION_ID"); // column number 0
info.out().addLongColumn("SEQUENCE_NO"); // column number 1
// Make all the input table columns also output columns,
// those are called "pass-through" columns. The default
// parameters of this method add all the columns of the
// first input table.
info.addPassThruColumns();
// set the function type, sessionize behaves like a reducer in
// MapReduce. Session ids are local within rows that share the
// same id column value.
info.setFuncType(UDRInvocationInfo::REDUCER);
}