本文整理匯總了Java中com.taobao.tddl.optimizer.core.ast.query.JoinNode.getJoinStrategy方法的典型用法代碼示例。如果您正苦於以下問題：Java JoinNode.getJoinStrategy方法的具體用法？Java JoinNode.getJoinStrategy怎麽用？Java JoinNode.getJoinStrategy使用的例子？那麽, 這裏精選的方法代碼示例或許可以為您提供幫助。您也可以進一步了解該方法所在類com.taobao.tddl.optimizer.core.ast.query.JoinNode的用法示例。
在下文中一共展示了JoinNode.getJoinStrategy方法的2個代碼示例，這些例子默認根據受歡迎程度排序。您可以為喜歡或者感覺有用的代碼點讚，您的評價將有助於係統推薦出更棒的Java代碼示例。
示例1: estimate
import com.taobao.tddl.optimizer.core.ast.query.JoinNode; //導入方法依賴的package包/類
public Cost estimate(QueryTreeNode query) {
JoinNode join = (JoinNode) query;
Cost leftCost = CostEsitimaterFactory.estimate(join.getLeftNode());
Cost rightCost = CostEsitimaterFactory.estimate(join.getRightNode());
Cost cost = new Cost();
cost.setIsOnFly(true);
long rowCount = 0;
long networkCost = 0;
long scanRowCount = 0;
boolean isOnFly = true;
// 估算IO開銷
if (rightCost.isOnFly()) {
cost.setDiskIO(leftCost.getDiskIO() + rightCost.getDiskIO());
} else {
cost.setDiskIO(leftCost.getDiskIO() + leftCost.getRowCount());
}
// 估算行數
// 現在假定join後的行數為較小表的行數，這個假設對於大多數場景都是成立的
if (leftCost.getRowCount() < rightCost.getRowCount()) {
rowCount = (leftCost.getRowCount());
} else {
rowCount = (rightCost.getRowCount());
}
// 估算網絡開銷
if (join.getDataNode() != null) {
if (!join.getDataNode().equals(join.getLeftNode().getDataNode())) {
networkCost += leftCost.getRowCount();
}
if (!join.getDataNode().equals(join.getRightNode().getDataNode())) {
networkCost += rightCost.getRowCount();
}
}
// 如果是IndexNestLoop，則數據還在磁盤上
if (join.getJoinStrategy() == JoinStrategy.INDEX_NEST_LOOP) {
cost.setDiskIO(leftCost.getRowCount());
isOnFly = false;
scanRowCount = leftCost.getScanCount() + rightCost.getScanCount();
} else {
// sort merge
// 右邊的先要拿出數據
// 再要將符合的數據插到臨時表
// 所以等於是兩次
scanRowCount = leftCost.getScanCount() + rightCost.getScanCount() * 2 + rightCost.getRowCount();
}
if (query.getLimitFrom() != null && query.getLimitTo() != null) {
Object from = query.getLimitFrom();
if (from instanceof IBindVal) {
from = ((IBindVal) from).getValue();
}
Object to = query.getLimitTo();
if (to instanceof IBindVal) {
to = ((IBindVal) from).getValue();
}
if (from instanceof Long && to instanceof Long) {
rowCount = ((Long) query.getLimitTo() - (Long) query.getLimitFrom());
}
} else if (query.getLimitFrom() != null || query.getLimitTo() != null) {
rowCount = rowCount / 2;
}
cost.setNetworkCost(networkCost);
cost.setRowCount(rowCount);
cost.setIsOnFly(isOnFly);
cost.setScanCount(scanRowCount);
return cost;
}
示例2: estimate
import com.taobao.tddl.optimizer.core.ast.query.JoinNode; //導入方法依賴的package包/類
public Cost estimate(QueryTreeNode query) throws StatisticsUnavailableException {
JoinNode join = (JoinNode) query;
Cost leftCost = CostEsitimaterFactory.estimate(join.getLeftNode());
Cost rightCost = CostEsitimaterFactory.estimate(join.getRightNode());
Cost cost = new Cost();
cost.setIsOnFly(true);
long rowCount = 0;
long networkCost = 0;
long scanRowCount = 0;
boolean isOnFly = true;
// 估算IO開銷
if (rightCost.isOnFly()) {
cost.setDiskIO(leftCost.getDiskIO() + rightCost.getDiskIO());
} else {
cost.setDiskIO(leftCost.getDiskIO() + leftCost.getRowCount());
}
// 估算行數
// 現在假定join後的行數為較小表的行數，這個假設對於大多數場景都是成立的
if (leftCost.getRowCount() < rightCost.getRowCount()) {
rowCount = (leftCost.getRowCount());
} else {
rowCount = (rightCost.getRowCount());
}
// 估算網絡開銷
if (join.getDataNode() != null) {
if (!join.getDataNode().equals(join.getLeftNode().getDataNode())) {
networkCost += leftCost.getRowCount();
}
if (!join.getDataNode().equals(join.getRightNode().getDataNode())) {
networkCost += rightCost.getRowCount();
}
}
// 如果是IndexNestLoop，則數據還在磁盤上
if (join.getJoinStrategy() == JoinStrategy.INDEX_NEST_LOOP) {
cost.setDiskIO(leftCost.getRowCount());
isOnFly = false;
scanRowCount = leftCost.getScanCount() + rightCost.getScanCount();
} else {
// sort merge
// 右邊的先要拿出數據
// 再要將符合的數據插到臨時表
// 所以等於是兩次
scanRowCount = leftCost.getScanCount() + rightCost.getScanCount() * 2 + rightCost.getRowCount();
}
if (query.getLimitFrom() != null
&& (query.getLimitFrom() instanceof Long || query.getLimitFrom() instanceof Long)
&& (Long) query.getLimitFrom() != 0 && query.getLimitTo() != null
&& (query.getLimitTo() instanceof Long || query.getLimitTo() instanceof Long)
&& (Long) query.getLimitTo() != 0) {
rowCount = ((Long) query.getLimitTo() - (Long) query.getLimitFrom());
} else if (query.getLimitFrom() != null || query.getLimitTo() != null) {
rowCount = rowCount / 2;
}
cost.setNetworkCost(networkCost);
cost.setRowCount(rowCount);
cost.setIsOnFly(isOnFly);
cost.setScanCount(scanRowCount);
return cost;
}