You can call the CreateSearchIndex operation to create one or more search indexes for a data table.

Prerequisites

  • A Tablestore client is initialized. For more information, see Initialization.
  • A data table is created for which the value of the timeToLive parameter is set to -1 and the value of the maxVersions parameter is set to 1.

Parameters

When you create a search index, you must configure the tableName, indexName, and indexSchema parameters. You must also configure the fieldSchemas, indexSetting, indexSort, and timeToLive parameters in indexSchema. The following table describes the parameters.
Parameter Description
tableName The name of the data table.
indexName The name of the search index.
fieldSchemas The list of field schemas. Each field schema contains the following parameters:
  • fieldName: This parameter is required and specifies the name of the field in the search index. The value is used as a column name. Type: String.

    A field in a search index can be a primary key column or an attribute column.

  • fieldType: This parameter is required and specifies the type of the field. Use FieldType.XXX to set the type. For more information, see Data types of column values.
  • array: This parameter is optional and specifies whether the value is an array. Type: Boolean.

    If you set this parameter to true, the column stores data as an array. Data written to the column must be a JSON array. Example: ["a","b","c"].

    The values of fields of the Nested type are arrays. If you set fieldType to Nested, skip this parameter.

  • index: This parameter is optional and specifies whether to enable indexing for the column. Type: Boolean.

    Default value: true. A value of true indicates that Tablestore indexes the column with an inverted indexing schema or a spatio-temporal indexing schema. A value of false indicates that Tablestore does not enable indexing for the column.

  • analyzer: This parameter is optional and specifies the type of the analyzer that you want to use. If fieldType is set to Text, you can configure this parameter. Otherwise, the default analyzer type single-word tokenization is used. For more information about tokenization, see Tokenization.
  • enableSortAndAgg: This parameter is optional and specifies whether to enable sorting and aggregation. Type: Boolean.
    Sorting can be enabled only for fields for which enableSortAndAgg is set to true. For more information about sorting, see Sorting and pagination.
    Notice Fields of the Nested type do not support sorting and aggregation, but subcolumns of fields of the Nested type support sorting and aggregation.
  • store: This parameter is optional and specifies whether to store the value of the field in the search index. Type: Boolean.

    If you set store to true, you can read the value of the field from the search index without querying the data table. This improves query performance.

  • isVirtualField: This parameter is optional and specifies whether the field is a virtual column. Type: Boolean. Default value: false. This parameter is required only when you use virtual columns. For more information about virtual columns, see Virtual columns.
  • sourceFieldName: This parameter is optional and specifies the name of the source field to which the virtual column is mapped in the data table. Type: String. This parameter is required when isVirtualField is set to true.
indexSetting The settings of the search index, including routingFields.

routingFields: This parameter is optional and specifies custom routing fields. You can specify some primary key columns as routing fields. Tablestore distributes data that is written to a search index across different partitions based on the specified routing fields. The data whose routing field values are the same is distributed to the same partition.

indexSort The presorting settings of the search index, including sorters. If no value is specified for the indexSort parameter, field values are sorted by primary key by default.
Note You can skip the presorting settings for search indexes that contain fields of the Nested type.
sorters: This parameter is required and specifies the presorting method for the search index. PrimaryKeySort and FieldSort are supported. For more information about sorting, see Sorting and pagination.
  • PrimaryKeySort: Data is sorted by primary key. You can configure the following parameter for PrimaryKeySort:

    order: the sort order. Data can be sorted in ascending or descending order. Default value: SortOrder.ASC.

  • FieldSort: Data is sorted by field value. You can configure the following parameters for FieldSort:

    Only fields for which indexing is enabled and enableSortAndAgg is set to true can be presorted.

    • fieldName: the name of the field that is used to sort data.
    • order: the sort order. Data can be sorted in ascending or descending order. Default value: SortOrder.ASC.
    • mode: the sorting method that is used when the field contains multiple values.
timeToLive This parameter is optional and specifies the retention period of data in the search index. Unit: seconds. Default value: -1.

When the retention period exceeds the timeToLive value, Tablestore automatically deletes expired data.

The minimum timeToLive value is 86400, which is equal to one day. A value of -1 specifies that data never expires.

Examples

  • Create a search index
    The following sample code shows how to create a search index that consists of the Col_Keyword and Col_Long columns. Set the type of data in Col_Keyword to String and Col_Long to Long.
    
    private static void createSearchIndex(SyncClient client) {
        CreateSearchIndexRequest request = new CreateSearchIndexRequest();
        request.setTableName(tableName); // Specify the name of the data table. 
        request.setIndexName(indexName); // Specify the name of the search index. 
        IndexSchema indexSchema = new IndexSchema();
        indexSchema.setFieldSchemas(Arrays.asList(
                new FieldSchema("Col_Keyword", FieldType.KEYWORD) // Specify the name and type of the field. 
                        .setIndex(true) // Enable indexing. 
                        .setEnableSortAndAgg(true) // Enable sorting and aggregation. 
                        .setStore(true), // Specify that the value of the field is stored in the search index. 
                new FieldSchema("Col_Long", FieldType.LONG)
                        .setIndex(true)
                        .setEnableSortAndAgg(true)
                        .setStore(true)));
        request.setIndexSchema(indexSchema);
        client.createSearchIndex(request); // Call a client to create the search index. 
    }
  • Create a search index with indexSort specified
    private static void createSearchIndexWithIndexSort(SyncClient client) {
        CreateSearchIndexRequest request = new CreateSearchIndexRequest();
        request.setTableName(tableName);
        request.setIndexName(indexName);
        IndexSchema indexSchema = new IndexSchema();
        indexSchema.setFieldSchemas(Arrays.asList(
                new FieldSchema("Col_Keyword", FieldType.KEYWORD).setIndex(true).setEnableSortAndAgg(true).setStore(true),
                new FieldSchema("Col_Long", FieldType.LONG).setIndex(true).setEnableSortAndAgg(true).setStore(true),
                new FieldSchema("Col_Text", FieldType.TEXT).setIndex(true).setStore(true),
                new FieldSchema("Timestamp", FieldType.LONG).setIndex(true).setEnableSortAndAgg(true).setStore(true)));
        // Presort data by the Timestamp column. You must enable indexing and set enableSortAndAgg to true for the Timestamp column. 
        indexSchema.setIndexSort(new Sort(
                Arrays.<Sort.Sorter>asList(new FieldSort("Timestamp", SortOrder.ASC))));
        request.setIndexSchema(indexSchema);
        client.createSearchIndex(request);
    }
  • Create a search index with the TTL specified
    Notice Make sure that updates to the data table are prohibited.
    // Use Tablestore SDK for Java V5.12.0 or later to create a search index. 
    public void createIndexWithTTL() {
        int days = 7;
        CreateSearchIndexRequest createRequest = new CreateSearchIndexRequest();
        createRequest.setTableName(tableName);
        createRequest.setIndexName(indexName);
        createRequest.setIndexSchema(indexSchema);
        // Specify the TTL for the search index. 
        createRequest.setTimeToLiveInDays(days);
        client.createSearchIndex(createRequest);
    }
  • Create a search index with virtual columns specified
    The following sample code shows how to create a search index that contains columns Col_Keyword and Col_Long. Each of the columns has a virtual column. The virtual column of the Col_Keyword column is Col_Keyword_Virtual_Long and that of the Col_Long column is Col_Long_Virtual_Keyword. The Col_Keyword_Virtual_Long column is mapped to the Col_Keyword column in the data table, and the Col_Long_Virtual_Keyword column is mapped to the Col_Long column in the data table.
    private static void createSearchIndex(SyncClient client) {
        CreateSearchIndexRequest request = new CreateSearchIndexRequest();
        request.setTableName(tableName); // Specify the name of the data table. 
        request.setIndexName(indexName); // Specify the name of the search index. 
        IndexSchema indexSchema = new IndexSchema();
        indexSchema.setFieldSchemas(Arrays.asList(
            new FieldSchema("Col_Keyword", FieldType.KEYWORD) // Specify the name and type of the field. 
                .setIndex(true) // Enable indexing. 
                .setEnableSortAndAgg(true) // Enable sorting and aggregation. 
                .setStore(true),
            new FieldSchema("Col_Keyword_Virtual_Long", FieldType.LONG) // Specify the name and type of the field. 
                .setIndex(true)
                .setEnableSortAndAgg(true)
                .setStore(true)
                .setVirtualField(true) // Specify whether the field is a virtual column. 
                .setSourceFieldName("Col_Keyword"), // Specify name of the source field to which the virtual column is mapped in the data table. 
            new FieldSchema("Col_Long", FieldType.LONG)
                .setIndex(true)
                .setEnableSortAndAgg(true)
                .setStore(true),
            new FieldSchema("Col_Long_Virtual_Keyword", FieldType.KEYWORD)
                .setIndex(true)
                .setEnableSortAndAgg(true)
                .setStore(true)
                .setVirtualField(true)
                .setSourceFieldName("Col_Long")));
        request.setIndexSchema(indexSchema);
        client.createSearchIndex(request); // Call a client to create the search index. 
    }