level2optimizerimpl.java

derby database source code.good for you.

					objectParam1 +
					" as truly the best for table " +
					intParam1 + 
					" for plan type " +
					(intParam2 == Optimizer.NORMAL_PLAN ?
										" normal " : "sort avoidance") +
					"\n";
				break;

			case NO_MORE_CONGLOMERATES:
				traceString =
					"No more conglomerates to consider for table " +
					intParam1;
				break;

			case CONSIDERING_CONGLOMERATE:
				cd = (ConglomerateDescriptor) objectParam1;
				cdString = dumpConglomerateDescriptor(cd);
				traceString =
					"\nConsidering conglomerate " +
					cdString +
					" for table " +
					intParam1;
				break;

			case SCANNING_HEAP_FULL_MATCH_ON_UNIQUE_KEY:
				traceString = "Scanning heap, but we have a full match on a unique key.";
				break;

			case ADDING_UNORDERED_OPTIMIZABLE:
				traceString = "Adding unordered optimizable, # of predicates = " + intParam1;
				break;

			case CHANGING_ACCESS_PATH_FOR_TABLE:
				traceString = "Changing access path for table " + intParam1;
				break;

			case TABLE_LOCK_NO_START_STOP:
				traceString = "Lock mode set to MODE_TABLE because no start or stop position";
				break;

			case NON_COVERING_INDEX_COST:
				traceString = 
					"Index does not cover query - cost including base row fetch is: " +
					doubleParam +
					" for table " + intParam1;
				break;

			case ROW_LOCK_ALL_CONSTANT_START_STOP:
				traceString = 
					"Lock mode set to MODE_RECORD because all start and stop positions are constant";
				break;

			case ESTIMATING_COST_OF_CONGLOMERATE:
				cd = (ConglomerateDescriptor) objectParam1;
				cdString = dumpConglomerateDescriptor(cd);
				traceString =
					"Estimating cost of conglomerate: " +
					costForTable(cdString, intParam1);
				break;
				
			case LOOKING_FOR_SPECIFIED_INDEX:
				traceString = 
					"Looking for user-specified index: " +
					objectParam1 + " for table " +
					intParam1;
				break;

			case MATCH_SINGLE_ROW_COST:
				traceString =
					"Guaranteed to match a single row - cost is: " +
					doubleParam + " for table " + intParam1;
				break;

			case COST_INCLUDING_EXTRA_1ST_COL_SELECTIVITY:
				traceString = costIncluding(
								"1st column", objectParam1, intParam1);
				traceString =
					"Cost including extra first column selectivity is : " +
					objectParam1 + " for table " + intParam1;
				break;

			case CALLING_NEXT_ACCESS_PATH:
				traceString =
					"Calling nextAccessPath() for base table " +
					objectParam1 + " with " + intParam1 + " predicates.";
				break;

			case TABLE_LOCK_OVER_THRESHOLD:
				traceString = lockModeThreshold("MODE_TABLE", "greater",
												doubleParam, intParam1);
				break;

			case ROW_LOCK_UNDER_THRESHOLD:
				traceString = lockModeThreshold("MODE_RECORD", "less",
												doubleParam, intParam1);
				break;

			case COST_INCLUDING_EXTRA_START_STOP:
				traceString = costIncluding(
								"start/stop", objectParam1, intParam1);
				break;

			case COST_INCLUDING_EXTRA_QUALIFIER_SELECTIVITY:
				traceString = costIncluding(
								"qualifier", objectParam1, intParam1);
				break;

			case COST_INCLUDING_EXTRA_NONQUALIFIER_SELECTIVITY:
				traceString = costIncluding(
								"non-qualifier", objectParam1, intParam1);
				break;

   		    case COST_INCLUDING_COMPOSITE_SEL_FROM_STATS:
				traceString = costIncluding("selectivity from statistics",
											objectParam1, intParam1);
				break;

			case COST_INCLUDING_STATS_FOR_INDEX:
				traceString = costIncluding("statistics for index being considered", 
											objectParam1, intParam1);
				break;
		    case COMPOSITE_SEL_FROM_STATS:
				traceString = "Selectivity from statistics found. It is " +
					doubleParam;
				break;

			case COST_OF_NONCOVERING_INDEX:
				traceString =
					"Index does not cover query: cost including row fetch is: " +
					costForTable(objectParam1, intParam1);
				break;

			case REMEMBERING_JOIN_STRATEGY:
				traceString =
					"\nRemembering join strategy " + objectParam1 +
					" as best for table " + intParam1;
				break;

			case REMEMBERING_BEST_ACCESS_PATH_SUBSTRING:
				traceString =
					"in best access path";
				break;

			case REMEMBERING_BEST_SORT_AVOIDANCE_ACCESS_PATH_SUBSTRING:
				traceString =
					"in best sort avoidance access path";
				break;

			case REMEMBERING_BEST_UNKNOWN_ACCESS_PATH_SUBSTRING:
				traceString =
					"in best unknown access path";
				break;

			case COST_OF_CONGLOMERATE_SCAN1:
				cd = (ConglomerateDescriptor) objectParam1;
				cdString = dumpConglomerateDescriptor(cd);
				traceString =
					"Cost of conglomerate " +
					cdString +
					" scan for table number " +
					intParam1 + " is : ";
				break;

			case COST_OF_CONGLOMERATE_SCAN2:
				traceString =
					objectParam1.toString();
				break;

			case COST_OF_CONGLOMERATE_SCAN3:
				traceString =
					"\tNumber of extra first column predicates is : " +
					intParam1 +
					", extra first column selectivity is : " +
					doubleParam;
				break;

			case COST_OF_CONGLOMERATE_SCAN4:
				traceString =
					"\tNumber of extra start/stop predicates is : " +
					intParam1 +
					", extra start/stop selectivity is : " +
					doubleParam;
				break;

			case COST_OF_CONGLOMERATE_SCAN5:
				traceString =
					"\tNumber of extra qualifiers is : " +
					intParam1 +
					", extra qualifier selectivity is : " +
					doubleParam;
				break;

			case COST_OF_CONGLOMERATE_SCAN6:
				traceString =
					"\tNumber of extra non-qualifiers is : " +
					intParam1 +
					", extra non-qualifier selectivity is : " +
					doubleParam;
				break;

		    case COST_OF_CONGLOMERATE_SCAN7:
				traceString = 
					"\tNumber of start/stop statistics predicates is : " +
					intParam1 + 
					", statistics start/stop selectivity is : " +
					doubleParam;
				break;
		}
		if (SanityManager.DEBUG)
		{
			if (traceString == null)
			{
				SanityManager.THROWASSERT(
					"traceString expected to be non-null");
			}
		}
		lcc.appendOptimizerTraceOutput(traceString + "\n");
	}

	private String costForTable(Object cost, int tableNumber)
	{
		return cost + " for table " + tableNumber;
	}

	private String bestCost()
	{
		return "Best cost = " + bestCost + "\n";
	}

	private String buildJoinOrder(String prefix, boolean addJoinOrderNumber,
								  int joinOrderNumber, int[] joinOrder)
	{
		String joinOrderString = prefix;

		for (int i = 0; i <= joinPosition; i++)
		{
			joinOrderString = joinOrderString + " " + joinOrder[i];
		}
		if (addJoinOrderNumber)
		{
			joinOrderString = joinOrderString + " " + joinOrderNumber;
		}

		return joinOrderString + " with assignedTableMap = " + assignedTableMap + "\n\n";
	}

	private String lockModeThreshold(
						String lockMode, String relop,
						double rowCount, int threshold)
	{
		return
			"Lock mode set to " + lockMode + 
			" because estimated row count of " + rowCount +
			" " + relop + " than threshold of " + threshold;
	}

	private String costIncluding(
					String selectivityType, Object objectParam1, int intParam1)
	{
		return
			"Cost including extra " + selectivityType +
			" start/stop selectivity is : " +
			costForTable(objectParam1, intParam1);
	}

	private String dumpConglomerateDescriptor(ConglomerateDescriptor cd)
	{
		if (SanityManager.DEBUG)
		{
			return cd.toString();
		}

		String		keyString = "";
		String[]	columnNames = cd.getColumnNames();

		if (cd.isIndex() && columnNames != null )
		{
			IndexRowGenerator irg = cd.getIndexDescriptor();

			int[] keyColumns = irg.baseColumnPositions();

			keyString = ", key columns = {" + columnNames[keyColumns[0] - 1];
			for (int index = 1; index < keyColumns.length; index++)
			{
				keyString = keyString + ", " + columnNames[keyColumns[index] - 1];
			}
			keyString = keyString + "}";
		}

		return "CD: conglomerateNumber = " + cd.getConglomerateNumber() +
			   " name = " + cd.getConglomerateName() +
			   " uuid = " + cd.getUUID() +
			   " indexable = " + cd.isIndex() +
			   keyString;
	}
}