// When candidate table does not have the field, this method checks
// if the field can be reached through reference,
// if yes adds the ref usage and returns to true, if not returns false.
boolean addRefUsage(CandidateTable table, String col, String srcTbl) throws LensException {
// available as referenced col
if (referencedCols.containsKey(col)) {
for (ReferencedQueriedColumn refer : referencedCols.get(col)) {
if (refer.srcTable.getName().equalsIgnoreCase(srcTbl)) {
// check if reference source column is available in src table?
// should not be required here. Join resolution will figure out if
// there is no path
// to the source table
log.info("Adding denormalized column for column:{} for table:{}", col, table);
Set<ReferencedQueriedColumn> refCols = tableToRefCols.get(table.getName());
if (refCols == null) {
refCols = new HashSet<>();
tableToRefCols.put(table.getName(), refCols);
}
refCols.add(refer);
// Add to optional tables
for (ChainRefCol refCol : refer.col.getChainRefColumns()) {
cubeql.addOptionalDimTable(
refCol.getChainName(),
table,
false,
refer.col.getName(),
true,
refCol.getRefColumn());
}
return true;
}
}
}
return false;
}
// updates all expression specs which are evaluable
public void updateEvaluables(String expr, CandidateTable cTable) throws SemanticException {
String alias = cubeql.getAliasForTableName(cTable.getBaseTable().getName());
ExpressionContext ec = getExpressionContext(expr, alias);
if (cTable.getColumns().contains(expr)) {
// expression is directly materialized in candidate table
ec.addDirectlyAvailable(cTable);
}
for (ExprSpecContext esc : ec.allExprs) {
if (esc.getTblAliasToColumns().get(alias) == null) {
log.debug("{} = {} is evaluable in {}", expr, esc, cTable);
ec.addEvaluable(cubeql, cTable, esc);
} else {
Set<String> columns = esc.getTblAliasToColumns().get(alias);
boolean isEvaluable = true;
for (String col : columns) {
if (!cTable.getColumns().contains(col.toLowerCase())) {
if (!cubeql
.getDeNormCtx()
.addRefUsage(cTable, col, cTable.getBaseTable().getName())) {
// check if it is available as reference, if not expression is not evaluable
log.debug("{} = {} is not evaluable in {}", expr, esc, cTable);
isEvaluable = false;
break;
}
}
}
if (isEvaluable) {
log.debug("{} = {} is evaluable in {}", expr, esc, cTable);
ec.addEvaluable(cubeql, cTable, esc);
}
}
}
}
private void pickExpressionsForTable(CandidateTable cTable) {
for (Map.Entry<String, Set<ExpressionContext>> ecEntry : allExprsQueried.entrySet()) {
Set<ExpressionContext> ecSet = ecEntry.getValue();
for (ExpressionContext ec : ecSet) {
if (ec.getSrcTable().getName().equals(cTable.getBaseTable().getName())) {
if (!ec.directlyAvailableIn.contains(cTable)) {
if (ec.evaluableExpressions.get(cTable) != null
&& !ec.evaluableExpressions.get(cTable).isEmpty()) {
// pick first evaluable expression
Set<PickedExpression> peSet = pickedExpressions.get(ecEntry.getKey());
if (peSet == null) {
peSet = new HashSet<PickedExpression>();
pickedExpressions.put(ecEntry.getKey(), peSet);
}
peSet.add(
new PickedExpression(
ec.srcAlias, ec.evaluableExpressions.get(cTable).iterator().next()));
}
}
}
}
}
}
// checks if expr is evaluable
public boolean isEvaluable(String expr, CandidateTable cTable) {
ExpressionContext ec =
getExpressionContext(expr, cubeql.getAliasForTableName(cTable.getBaseTable().getName()));
return ec.isEvaluable(cTable);
}
