Author: jolee Date: 2012-09-10 15:24:46 -0400 (Mon, 10 Sep 2012) New Revision: 4421 Modified: branches/7.7.x/engine/src/main/java/org/teiid/query/tempdata/TempTable.java Log: TEIID-2185 correcting cost estimation for index selection Modified: branches/7.7.x/engine/src/main/java/org/teiid/query/tempdata/TempTable.java =================================================================== --- branches/7.7.x/engine/src/main/java/org/teiid/query/tempdata/TempTable.java 2012-09-10 18:40:32 UTC (rev 4420) +++ branches/7.7.x/engine/src/main/java/org/teiid/query/tempdata/TempTable.java 2012-09-10 19:24:46 UTC (rev 4421) @@ -324,9 +324,9 @@ int startIndex = 0; if (primaryKeyLength == 0) { startIndex = 1; - ElementSymbol id = new ElementSymbol("rowId"); //$NON-NLS-1$ - id.setType(DataTypeManager.DefaultDataClasses.INTEGER); - columns.add(0, id); + ElementSymbol rid = new ElementSymbol("rowId"); //$NON-NLS-1$ + rid.setType(DataTypeManager.DefaultDataClasses.INTEGER); + columns.add(0, rid); rowId = new AtomicInteger(); tree = bm.createSTree(columns, sessionID, 1); } else { @@ -444,10 +444,10 @@ if (indexTables != null && (condition != null || orderBy != null) && ii.valueSet.size() != 1) { LogManager.logDetail(LogConstants.CTX_DQP, "Considering indexes on table", this, "for query", projectedCols, condition, orderBy); //$NON-NLS-1$ //$NON-NLS-2$ int rowCost = this.tree.getRowCount(); - int bestCost = estimateCost(orderBy, ii, rowCost); + long bestCost = estimateCost(orderBy, ii, rowCost); for (TempTable table : this.indexTables.values()) { IndexInfo secondary = new IndexInfo(table, projectedCols, condition, orderBy, false); - int cost = estimateCost(orderBy, secondary, rowCost); + long cost = estimateCost(orderBy, secondary, rowCost); if (cost < bestCost) { ii = secondary; bestCost = cost; @@ -521,25 +521,36 @@ * to compute them, since it minimizes page loads, and is a random sample. * TODO: this should also factor in the block size */ - private int estimateCost(OrderBy orderBy, IndexInfo ii, int rowCost) { - int initialCost = rowCost; + private long estimateCost(OrderBy orderBy, IndexInfo ii, long rowCost) { + long initialCost = rowCost; + long additionalCost = 0; if (ii.valueSet.size() != 0) { int length = ii.valueSet.get(0).size(); - rowCost = ii.valueSet.size() * (ii.table.getPkLength() - length + 1); + rowCost = ii.valueSet.size(); + additionalCost = rowCost * (64 - Long.numberOfLeadingZeros(initialCost - 1)); if (ii.table.uniqueColIndex != length) { - rowCost *= 3; + rowCost *= 3*(ii.table.uniqueColIndex - length); } + if (rowCost > initialCost) { + additionalCost = rowCost - initialCost; + rowCost = initialCost; + } } else if (ii.upper != null) { + additionalCost = (64 - Long.numberOfLeadingZeros(initialCost - 1)); rowCost /= 3; } else if (ii.lower != null) { + additionalCost = (64 - Long.numberOfLeadingZeros(initialCost - 1)); rowCost /= 3; } - int additionalCost = Math.max(0, initialCost - rowCost); - int cost = Math.min(initialCost, Math.max(1, rowCost)); - if (cost > 1 && (!ii.covering || (orderBy != null && ii.ordering == null))) { - cost *= (32 - Integer.numberOfLeadingZeros(cost - 1)); + if (rowCost > 1 && (!ii.covering || (orderBy != null && ii.ordering == null))) { + //pk order or non-covered ordering + rowCost *= (64 - Long.numberOfLeadingZeros(rowCost - 1)); + if (!ii.covering) { + //primary lookup + rowCost *= 2; + } } - return cost + additionalCost; + return rowCost + additionalCost; } private TupleBrowser createTupleBrower(Criteria condition, boolean direction) throws TeiidComponentException {