如何访问BigQuery结果集的cacheHit属性?

问题描述

显然，当使用BigQuery API时，BigQuery结果有一个cacheHit属性.我尝试找到此属性，但不确定如何访问它.这是我使用BigQuery API的Java代码. cacheHit不是我得到的TableResult tr的属性:

Apparently, when using the BigQuery API, there is a cacheHit property of a BigQuery result. I've tried finding this property and I'm not sure how I need to access it. Here's my Java code that uses the BigQuery API. cacheHit isn't a property of the TableResult tr that I get:

try
{
    QueryJobConfiguration queryJobConfiguration =

        QueryJobConfiguration.newBuilder(
                "mySQLqueryText"
        )
        .setUseLegacySql(false)
        .setAllowLargeResults(false)
        .setUseQueryCache(true)
        .build();

    try {
        TableResult tr = bigQuery.query(queryJobConfiguration);

        Iterable<FieldValueList> rowList = tr.getValues();

        ....
    }
    catch (BigQueryException e) {
        // do stuff
    }
} catch (InterruptedException e) {
    e.printStackTrace();
}

我看了这个问题- BigQuery cacheHit属性

...但是那不是Java，而且我还没有找到我可以使用的任何results()属性，如该问题所示.

... but that's not Java, and I haven't found any results() property I can use, as suggested in that question.

这里有一些有关 JobStatistics2 的文档.对象，显然具有cacheHit属性.

There's some documentation here about the JobStatistics2 object, that apparently has a cacheHit property.

我可以得到一个JobStatistics(不是一个JobStatistics2对象)，像这样:

I can get a JobStatistics (not a JobStatistics2 object), like this:

QueryJobConfiguration queryJobConfiguration =

    QueryJobConfiguration.newBuilder(
            "myQueryString"
    )
    .setUseLegacySql(false)
    .setAllowLargeResults(false)
    .setUseQueryCache(true)
    .build();

    JobId jobId = JobId.of(UUID.randomUUID().toString());
    Job queryJob = bigQuery.create(JobInfo.newBuilder(queryJobConfiguration).setJobId(jobId).build());

try {

    queryJob = queryJob.waitFor();

    if (queryJob != null) {

        JobStatistics js = queryJob.getStatistics();

    Iterable<FieldValueList> rowList = bigQuery.query(queryJobConfiguration).getValues();

...但是我在js上看不到任何cacheHit属性.当我尝试创建JobStatistics2时，通过更改实例化JobStatistics的行，如下所示:

... but I don't see any cacheHit property on js. When I try creating a JobStatistics2 instead, by changing the line where I'm instantiating JobStatistics, like this:

JobStatistics2 js = queryJob.getStatistics();

我收到错误Type parameter S has incompatible upper bounds: JobStatistics and JobStatistics2.这并不意味着什么，当我搜索Google错误时，没有任何有用的结果.

I get an error Type parameter S has incompatible upper bounds: JobStatistics and JobStatistics2. This doesn't mean much, and when I Google the error there are no useful results.

我觉得Google文档没有太大用处.如何访问cacheHit属性，并仍然获得代码示例中所示的rowList?

I'm not finding the Google documentation too useful. How can I access the cacheHit property, and still obtain my rowList as shown in the code example?

推荐答案

QueryStatistics是JobStatistics的嵌套类之一，可以看到此处，并且具有 getCacheHit() 方法:

QueryStatistics is one of the nested classes of JobStatistics as can be seen here and has a getCacheHit() method:

import com.google.cloud.bigquery.JobStatistics.QueryStatistics;

...

QueryStatistics js = queryJob.getStatistics();

System.out.println(js.getCacheHit());

请参见完整代码此处用于我的测试.

See full code here for my test.

关于JobStatistics2，这是针对com.google.api.services.bigquery库而不是com.google.cloud.bigquery.在这种情况下，您可以使用 getQuery() 从JobStatistics获取一个JobStatistics2对象，然后使用"> .

Regarding JobStatistics2 this is for com.google.api.services.bigquery library and not com.google.cloud.bigquery. In that case you could use getQuery() from JobStatistics to get a JobStatistics2 object and then use getCacheHit().

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