@Override
protected void doPrepare() {
expressions = prepared.getExpressions();
if (prepared.isGroupQuery()) {
ArrayList<Expression> selectExprs = New.arrayList(10);
int[] groupIndex = prepared.getGroupIndex();
for (int i = 0; i < groupIndex.length; i++) {
int idx = groupIndex[i];
Expression expr = expressions.get(idx);
selectExprs.add(expr);
}
HashSet<Aggregate> aggregates = New.hashSet();
for (Expression expr : expressions) {
expr.isEverything(ExpressionVisitor.getAggregateVisitor(aggregates));
}
selectExprs.addAll(aggregates);
expressions = selectExprs;
}
Expression[] exprList = expressions.toArray(new Expression[expressions.size()]);
Integer limit = null, offset = null;
Expression limitExpr = prepared.getLimit();
Expression offsetExpr = prepared.getOffset();
if (limitExpr != null) {
limit = limitExpr.getValue(session).getInt();
}
if (offsetExpr != null) {
offset = offsetExpr.getValue(session).getInt();
}
RoutingResult rr = doRoute(prepared);
if (rr.isMultipleNode() && offset != null) {
if (offset > database.getSettings().analyzeSample) {
throw DbException.get(
ErrorCode.INVALID_VALUE_2,
"offset",
offset
+ ", the max support offset "
+ database.getSettings().analyzeSample
+ " is defined by analyzeSample.");
}
offset = offset != null ? 0 : offset;
}
ObjectNode[] selectNodes = rr.getSelectNodes();
if (session.getDatabase().getSettings().optimizeMerging) {
selectNodes = rr.group();
}
workers = New.arrayList(selectNodes.length);
for (ObjectNode node : selectNodes) {
QueryWorker queryHandler =
queryHandlerFactory.createQueryWorker(
prepared, node, consistencyTableNodes, exprList, limit, offset);
workers.add(queryHandler);
}
}
