Use Tablestore SDK for Go to retrieve time series based on specific conditions - Tablestore

If you are unsure about the time series information to query, such as the measurement name or data source, or if you need to list time series based on specific conditions, you can use the QueryTimeseriesMeta operation to retrieve time series by specifying conditions such as the measurement name, data source, tag, attribute, and update time.

Prerequisites

Time series data is written to the time series table. For more information, see Write time series data.
A TimeseriesClient instance is initialized. For more information, see Initialize a Tablestore client.

Parameters

The metaQueryCondition parameter specifies the conditions for a time series retrieval. The conditions include compositeMetaQueryCondition, measurementMetaQueryCondition, dataSourceMetaQueryCondition, tagMetaQueryCondition, attributeMetaQueryCondition, and updateTimeMetaQueryCondition. The following table describes the parameters.

Parameter	Required	Description
compositeMetaQueryCondition	No	The composite condition, which includes the following content: operator: the logical operator. Valid logical operators: AND, OR, and NOT. subConditions: the subconditions that can be combined by using operators for complex queries.
measurementMetaQueryCondition	Yes. You must specify one of the parameters.	The metric name condition, which includes the following content: operator: the relational operator or prefix match condition. Valid relational operators: `=`, `>`, `>=`, `<`, and `<=`. value: the name of the metric of the time series that you want to query. Type: STRING.
dataSourceMetaQueryCondition		The data source condition, which includes the following content: operator: the relational operator or prefix match condition. Valid relational operators: `=`, `>`, `>=`, `<`, and `<=`. value: the data source of the time series that you want to query. Type: STRING.
tagMetaQueryCondition		The tag condition, which includes the following content: operator: the relational operator or prefix match condition. Valid relational operators: `=`, `>`, `>=`, `<`, and `<=`. value: the value of the tag of the time series that you want to query. Type: STRING.
attributeMetaQueryCondition		The attribute condition for the metadata of the time series. The attribute condition includes the following content: operator: the relational operator or prefix match condition. Valid relational operators: `=`, `>`, `>=`, `<`, and `<=`. attributeName: the name of the attribute. Type: STRING. value: the value of the attribute. Type: STRING.
updateTimeMetaQueryCondition		The update time condition for the metadata of the time series. The update time condition includes the following content: operator: the relational operator. Valid relational operators: `=`, `>`, `>=`, `<`, and `<=`. timeInUs: the timestamp when the time series metadata was updated. Unit: microseconds.

Examples

The following sample code provides an example on how to query the metric name, data source, and tags of the time series based on the specified condition. The specified condition can be a composite condition.

func QueryTimeseriesMetaSample(client *tablestore.TimeseriesClient , timeseriesTableName string) {
    fmt.Println("[Info]: Begin to query timeseries table meta!")

    // Construct multiple query conditions. 
    measurementMetaQueryCondition := tablestore.NewMeasurementQueryCondition(tablestore.OP_GREATER_EQUAL , "")
    datasourceMetaQueryCondition := tablestore.NewDataSourceMetaQueryCondition(tablestore.OP_GREATER_EQUAL , "")
    tagMetaQueryCondition := tablestore.NewTagMetaQueryCondition(tablestore.OP_GREATER_THAN , "City" , "")

    // Construct a composite condition. 
    compsiteMetaQueryCondition := tablestore.NewCompositeMetaQueryCondition(tablestore.OP_AND)
    compsiteMetaQueryCondition.AddSubConditions(measurementMetaQueryCondition)
    compsiteMetaQueryCondition.AddSubConditions(datasourceMetaQueryCondition)
    compsiteMetaQueryCondition.AddSubConditions(tagMetaQueryCondition)

    // Construct the query request. 
    queryTimeseriesMetaRequest := tablestore.NewQueryTimeseriesMetaRequest(timeseriesTableName)
    queryTimeseriesMetaRequest.SetCondition(compsiteMetaQueryCondition)
    queryTimeseriesMetaRequest.SetLimit(-1)

    // Call the time series client-related operation to execute the query request. 
    queryTimeseriesTableResponse , err := client.QueryTimeseriesMeta(queryTimeseriesMetaRequest)
    if err != nil {
        fmt.Println("[Error]: Query timeseries table meta failed with error: " , err)
        return
    }
    fmt.Println("[Info]: Query timeseries table meta succeed: ")
    for i := 0; i < len(queryTimeseriesTableResponse.GetTimeseriesMetas()); i++ {
        curTimeseriesMeta := queryTimeseriesTableResponse.GetTimeseriesMetas()[i]
        fmt.Println("[Info]: Meta_" , i , ": " , "Measurement: " , curTimeseriesMeta.GetTimeseriesKey().GetMeasurementName() ,
            "Source: " , curTimeseriesMeta.GetTimeseriesKey().GetDataSource() ,
            "Tags: " , curTimeseriesMeta.GetTimeseriesKey().GetTags(),
            "Attrs: " , curTimeseriesMeta.GetAttributeSlice())
    }
    fmt.Println("[Info]: QueryTimeseriesMetaSample finished !")
}

FAQ

References

For more information about the API operation, see QueryTimeseriesMeta.
If the attributes in the metadata of a time series do not meet your business requirements, you can update or delete time series metadata. For more information, see Update time series metadata and Delete time series metadata.
After you retrieve the required time series, you can query time series data based on the time series. For more information, see Query time series data.