[CALCITE-2175] Revisit the assumption made by druid calcite adapter that there is only one timestamp column

• Type: Task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.23.0
• Component/s: druid-adapter
• Assignee: Danny Chen
• Reporter: Slim Bouguerra
• Created: 12/Feb/18 15:46
• Updated: 24/May/20 11:59
• Resolved: 17/Apr/20 08:40

Description

Currently, the Druid Calcite adapter assumes that the row returned by druid has only one timestamp typed column, this is not true, in fact, we can have multiple projections of the time column with extraction functions. Thus code like this need to be revisited. 

int posTimestampField = -1;
for (int i = 0; i < fieldTypes.size(); i++) {
if (fieldTypes.get(i) == ColumnMetaData.Rep.JAVA_SQL_TIMESTAMP) {
 posTimestampField = i;
 break;
 }
}