@Override public void rewriteContext(CubeQueryContext cubeql) throws SemanticException { ExpressionResolverContext exprCtx = cubeql.getExprCtx(); if (exprCtx == null) { exprCtx = new ExpressionResolverContext(cubeql); cubeql.setExprCtx(exprCtx); for (Map.Entry<String, Set<String>> entry : cubeql.getTblAliasToColumns().entrySet()) { String alias = entry.getKey(); // skip default alias if (alias == CubeQueryContext.DEFAULT_TABLE) { continue; } AbstractCubeTable tbl = cubeql.getCubeTableForAlias(alias); 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 ExprColumn) { exprCtx.addExpressionQueried( new ExpressionContext(cubeql, (ExprColumn) col, (AbstractBaseTable) tbl, alias)); } } } Set<String> exprsWithMeasures = new HashSet<String>(); for (String expr : cubeql.getQueriedExprs()) { if (cubeql.getExprCtx().hasMeasures(expr, cubeql.getCube())) { // expression has measures exprsWithMeasures.add(expr); } } cubeql.addQueriedExprsWithMeasures(exprsWithMeasures); } else { // prune invalid expressions cubeql.getExprCtx().pruneExpressions(); // prune candidate facts without any valid expressions if (cubeql.getCube() != null && !cubeql.getCandidateFacts().isEmpty()) { for (Map.Entry<String, Set<ExpressionContext>> ecEntry : exprCtx.allExprsQueried.entrySet()) { String expr = ecEntry.getKey(); Set<ExpressionContext> ecSet = ecEntry.getValue(); for (ExpressionContext ec : ecSet) { if (ec.getSrcTable().getName().equals(cubeql.getCube().getName())) { if (cubeql.getQueriedExprsWithMeasures().contains(expr)) { for (Iterator<Set<CandidateFact>> sItr = cubeql.getCandidateFactSets().iterator(); sItr.hasNext(); ) { Set<CandidateFact> factSet = sItr.next(); boolean evaluableInSet = false; for (CandidateFact cfact : factSet) { if (ec.isEvaluable(cfact)) { evaluableInSet = true; } } if (!evaluableInSet) { log.info( "Not considering fact table set:{} as {} is not evaluable", factSet, ec.exprCol.getName()); sItr.remove(); } } } else { for (Iterator<CandidateFact> i = cubeql.getCandidateFacts().iterator(); i.hasNext(); ) { CandidateFact cfact = i.next(); if (!ec.isEvaluable(cfact)) { log.info( "Not considering fact table:{} as {} is not evaluable", cfact, ec.exprCol.getName()); cubeql.addFactPruningMsgs( cfact.fact, CandidateTablePruneCause.expressionNotEvaluable(ec.exprCol.getName())); i.remove(); } } } } } } cubeql.pruneCandidateFactWithCandidateSet(CandidateTablePruneCode.EXPRESSION_NOT_EVALUABLE); } // prune candidate dims without any valid expressions 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(); for (Map.Entry<String, Set<ExpressionContext>> ecEntry : exprCtx.allExprsQueried.entrySet()) { Set<ExpressionContext> ecSet = ecEntry.getValue(); for (ExpressionContext ec : ecSet) { if (ec.getSrcTable().getName().equals(cdim.getBaseTable().getName())) { if (!ec.isEvaluable(cdim)) { log.info( "Not considering dim table:{} as {} is not evaluable", cdim, ec.exprCol.getName()); cubeql.addDimPruningMsgs( dim, cdim.dimtable, CandidateTablePruneCause.expressionNotEvaluable(ec.exprCol.getName())); i.remove(); } } } } } } } } }
// 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); }