private void addRefColsQueried(
CubeQueryContext cubeql, TrackQueriedColumns tqc, DenormalizationContext denormCtx) {
for (Map.Entry<String, Set<String>> entry : tqc.getTblAliasToColumns().entrySet()) {
// skip default alias
if (entry.getKey() == CubeQueryContext.DEFAULT_TABLE) {
continue;
}
// skip join chain aliases
if (cubeql.getJoinchains().keySet().contains(entry.getKey().toLowerCase())) {
continue;
}
AbstractCubeTable tbl = cubeql.getCubeTableForAlias(entry.getKey());
Set<String> columns = entry.getValue();
for (String column : columns) {
CubeColumn col;
if (tbl instanceof CubeInterface) {
col = ((CubeInterface) tbl).getColumnByName(column);
} else {
col = ((Dimension) tbl).getColumnByName(column);
}
if (col instanceof ReferencedDimAttribute) {
// considering all referenced dimensions to be denormalized columns
denormCtx.addReferencedCol(
column, new ReferencedQueriedColumn((ReferencedDimAttribute) col, tbl));
}
}
}
}
/**
* Find all de-normalized columns, if these columns are not directly available in candidate
* tables, query will be replaced with the corresponding table reference
*/
@Override
public void rewriteContext(CubeQueryContext cubeql) throws LensException {
DenormalizationContext denormCtx = cubeql.getDeNormCtx();
if (denormCtx == null) {
// Adds all the reference dimensions as eligible for denorm fields
denormCtx = new DenormalizationContext(cubeql);
cubeql.setDeNormCtx(denormCtx);
// add ref columns in cube
addRefColsQueried(cubeql, cubeql, denormCtx);
// add ref columns from expressions
for (Set<ExpressionContext> ecSet : cubeql.getExprCtx().getAllExprsQueried().values()) {
for (ExpressionContext ec : ecSet) {
for (ExprSpecContext esc : ec.getAllExprs()) {
addRefColsQueried(cubeql, esc, denormCtx);
}
}
}
} else if (!denormCtx.tableToRefCols.isEmpty()) {
// In the second iteration of denorm resolver
// candidate tables which require denorm fields and the refernces are no
// more valid will be pruned
if (cubeql.getCube() != null && !cubeql.getCandidateFacts().isEmpty()) {
for (Iterator<CandidateFact> i = cubeql.getCandidateFacts().iterator(); i.hasNext(); ) {
CandidateFact cfact = i.next();
if (denormCtx.tableToRefCols.containsKey(cfact.getName())) {
for (ReferencedQueriedColumn refcol : denormCtx.tableToRefCols.get(cfact.getName())) {
if (denormCtx.getReferencedCols().get(refcol.col.getName()).isEmpty()) {
log.info(
"Not considering fact table:{} as column {} is not available",
cfact,
refcol.col);
cubeql.addFactPruningMsgs(
cfact.fact, CandidateTablePruneCause.columnNotFound(refcol.col.getName()));
i.remove();
}
}
}
}
if (cubeql.getCandidateFacts().size() == 0) {
throw new LensException(
LensCubeErrorCode.NO_FACT_HAS_COLUMN.getLensErrorInfo(),
cubeql.getColumnsQueried(cubeql.getCube().getName()).toString());
}
cubeql.pruneCandidateFactSet(CandidateTablePruneCode.COLUMN_NOT_FOUND);
}
if (cubeql.getDimensions() != null && !cubeql.getDimensions().isEmpty()) {
for (Dimension dim : cubeql.getDimensions()) {
for (Iterator<CandidateDim> i = cubeql.getCandidateDimTables().get(dim).iterator();
i.hasNext(); ) {
CandidateDim cdim = i.next();
if (denormCtx.tableToRefCols.containsKey(cdim.getName())) {
for (ReferencedQueriedColumn refcol : denormCtx.tableToRefCols.get(cdim.getName())) {
if (denormCtx.getReferencedCols().get(refcol.col.getName()).isEmpty()) {
log.info(
"Not considering dim table:{} as column {} is not available",
cdim,
refcol.col);
cubeql.addDimPruningMsgs(
dim,
cdim.dimtable,
CandidateTablePruneCause.columnNotFound(refcol.col.getName()));
i.remove();
}
}
}
}
if (cubeql.getCandidateDimTables().get(dim).size() == 0) {
throw new LensException(
LensCubeErrorCode.NO_DIM_HAS_COLUMN.getLensErrorInfo(),
dim.toString(),
cubeql.getColumnsQueried(dim.getName()).toString());
}
}
}
}
}