Use Tablestore SDK for Java to delete mapping tables - Tablestore

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.

Note

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 mapping tables for tables.

Usage notes

Tablestore SDK for Java V5.13.0 or later supports the SQL query feature. Before you use the SQL query feature, make sure that Tablestore SDK for Java V5.13.0 or later is obtained. For more information about the version history of Tablestore SDK for Java, see Version history of Tablestore SDK for Java.

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:

private static void dropMappingTable(SyncClient client) {
    // Create an SQL request. If you want to delete multiple mapping tables, separate the mapping tables with commas (,). 
    SQLQueryRequest request = new SQLQueryRequest("drop mapping table test_table");

    client.sqlQuery(request);
}

References

If an attribute column of a data table changes, 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.