9:24 p.m.
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 {