If you no longer require a mapping table, you can execute the DROP MAPPING TABLE statement to delete the mapping table. You can delete multiple mapping tables in a single request.
For more information about the DROP MAPPING TABLE statement, see Delete mapping tables.
Prerequisites
An OTSClient instance is initialized. For more information, see Initialize an OTSClient instance.
A mapping table is created. For more information, see Create a mapping table.
Parameters
Parameter | Description |
query | The SQL statement. Configure the parameter based on the required feature. |
Examples
The following sample code provides an example on how to execute the drop mapping table test_table statement to delete mapping tables that are created for the table named test_table:
func dropMappingTable(client *tablestore.TableStoreClient) {
// Create an SQL request.
request := &tablestore.SQLQueryRequest{Query: "drop mapping table test_table"}
// Obtain the response to the SQL request.
res, err := client.SQLQuery(request)
if err != nil {
fmt.Println(err.Error())
} else {
fmt.Println(res.ResponseInfo.RequestId)
}
}
References
If an attribute column of a data table is changed, you can execute the
ALTER TABLE
statement to modify the mapping table that is created for the data table. For more information, see Update attribute columns of mapping tables.If you want to accelerate data queries and computing by executing SQL statements, you can create a secondary index or a search index. For more information, see Index selection policy and Computing pushdown.
You can also use computing engines, such as MaxCompute, Spark, Hive, HadoopMR, Function Compute, Flink, and PrestoDB, to compute and analyze data in tables. For more information, see Overview.
If your business requires multi-dimensional queries and data analysis, you can create a search index and specify the required attributes as the fields of the search index. Then, you can use the search index to query and analyze data. For example, you can use a search index to perform queries based on non-primary key columns, Boolean queries, and fuzzy queries. You can also use a search index to obtain the maximum and minimum values, collect statistics about the number of rows, and group query results. For more information, see Search indexes.