本文整理汇总了Java中com.taobao.tddl.optimizer.core.ast.query.JoinNode.getJoinStrategy方法的典型用法代码示例。如果您正苦于以下问题：Java JoinNode.getJoinStrategy方法的具体用法？Java JoinNode.getJoinStrategy怎么用？Java JoinNode.getJoinStrategy使用的例子？那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类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个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Java代码示例。
示例1: estimate
import com.taobao.tddl.optimizer.core.ast.query.JoinNode; //导入方法依赖的package包/类
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开销
if (rightCost.isOnFly()) {
cost.setDiskIO(leftCost.getDiskIO() + rightCost.getDiskIO());
} else {
cost.setDiskIO(leftCost.getDiskIO() + leftCost.getRowCount());
}
// 估算行数
// 现在假定join后的行数为较小表的行数，这个假设对于大多数场景都是成立的
if (leftCost.getRowCount() < rightCost.getRowCount()) {
rowCount = (leftCost.getRowCount());
} else {
rowCount = (rightCost.getRowCount());
}
// 估算网络开销
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，则数据还在磁盘上
if (join.getJoinStrategy() == JoinStrategy.INDEX_NEST_LOOP) {
cost.setDiskIO(leftCost.getRowCount());
isOnFly = false;
scanRowCount = leftCost.getScanCount() + rightCost.getScanCount();
} else {
// sort merge
// 右边的先要拿出数据
// 再要将符合的数据插到临时表
// 所以等于是两次
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; //导入方法依赖的package包/类
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开销
if (rightCost.isOnFly()) {
cost.setDiskIO(leftCost.getDiskIO() + rightCost.getDiskIO());
} else {
cost.setDiskIO(leftCost.getDiskIO() + leftCost.getRowCount());
}
// 估算行数
// 现在假定join后的行数为较小表的行数，这个假设对于大多数场景都是成立的
if (leftCost.getRowCount() < rightCost.getRowCount()) {
rowCount = (leftCost.getRowCount());
} else {
rowCount = (rightCost.getRowCount());
}
// 估算网络开销
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，则数据还在磁盘上
if (join.getJoinStrategy() == JoinStrategy.INDEX_NEST_LOOP) {
cost.setDiskIO(leftCost.getRowCount());
isOnFly = false;
scanRowCount = leftCost.getScanCount() + rightCost.getScanCount();
} else {
// sort merge
// 右边的先要拿出数据
// 再要将符合的数据插到临时表
// 所以等于是两次
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;
}