This topic describes how to use HoloWeb to create, edit, and delete an internal table. This topic also describes how to preview the data and the Data Definition Language (DDL) statement of the internal table.

Prerequisites

  • An Alibaba Cloud account is created.
  • Real-name verification is completed.
  • A Hologres instance is purchased. For more information, see Purchase a Hologres instance.

Create an internal table

  1. Connect the purchased Hologres instance to HoloWeb. For more information, see Manage a connection.
  2. In the top navigation bar of the HoloWeb console, choose Connection Management > Table.
    You can also go to the New internal table tab by performing the following steps:
    1. In the left-side navigation pane, choose Connection Management > My connection. All the configured connections are displayed.
    2. Click the required connection and then click Database. All the created databases are displayed.
    3. Click the required database and then click Mode. All the available modes are displayed.
    4. Right-click the required schema and select New internal table.
  3. On the New internal table tab, set the parameters as required.New internal table
    Category Parameter Description
    Basic information Connection name The name of the required connection.
    Database The name of the Hologres database.
    Table name The name of the Hologres internal table.
    Description The description of the Hologres internal table.
    Mode The name of the schema.

    Default value: public. You can also select a custom schema.

    Field Field name The name of the field in the internal table.
    Date type The data type of the field.
    Primary key Specifies whether to use the field as the primary key for the internal table.
    Nullable Specifies whether the field can be left empty.
    Array Specifies whether the field is an ordered array of elements.
    Description The description of the field.
    Operation You can click Delete to delete the field and click Move up or Move down to move the field up or down.
    Attribute Storage mode Valid values: Column storage and Row deposit.

    Default value: Column storage.

    Life Cycle (seconds) If a record is not updated within the specified period, the system deletes the record.

    By default, the system retains records permanently.
    Clustered index The index that is used to sort columns.

    The type of index determines the order of fields. By using clustered indexes, Hologres can accelerate range and filter queries on index fields.

    Segment Key The fields that is used for segmenting. If the specified fields are involved in the query conditions, Hologres can find the storage location of data based on the fields.
    Dictionary encoding column The fields based on whose values a dictionary mapping is built.

    Dictionary encoding can convert string comparisons to numeric comparisons to accelerate queries such as GROUP BY and FILTER.

    By default, the system selects all the fields of the text type for this parameter.

    Bitmap columns Hologres allows you to build bit codes on bit fields.

    You can filter the data that meets the query conditions based on the specified fields by using Hologres.

    By default, the system selects all the fields of the text type for this parameter.

    Partition Table N/A The partition fields of the internal table.
  4. Click Submit form.
    On the configuration tab of the internal table, you can click Query table in the upper-right corner to go to the SQL query window, and query data by using SQL statements.

Edit an internal table

  1. In the left-side navigation pane, click My connection. All the configured connections are displayed.
  2. Click the required connection and then click Database. All the created databases are displayed.
  3. Click the required database and then click Mode. All the available modes are displayed.
  4. Click the required mode and then click Table. All the created internal tables are displayed.
  5. Right-click the required internal table and select Edit table.
  6. Click Add Field. In the section that appears, add a field to the internal table in visualized mode. You can also view the corresponding SQL statements and operational logs in the Run Log section when you submit the internal table.Edit
    Note You cannot delete a submitted field in an internal table when you edit the table.
  7. Click Submit form.

Delete an internal table

  1. In the left-side navigation pane, click My connection. Then, find the required internal table.
    For more information about how to find the required internal table, see Step 1 to Step 4 in Edit an internal table.
  2. Right-click the required internal table and select Delete table.
  3. Click OK.

Preview the table data

  1. In the left-side navigation pane, click My connection. Then, find the required internal table.
    For more information about how to find the required internal table, see Step 1 to Step 4 in Edit an internal table.
  2. Double-click the required internal table and click Data preview on the configuration tab of the table.
    Preview the table data, as shown in the following figure.Data preview

Preview the DDL statement

  1. In the left-side navigation pane, click My connection. Then, find the required internal table.
    For more information about how to find the required internal table, see Step 1 to Step 4 in Edit an internal table.
  2. Double-click the required internal table and click DDL statement on the configuration tab of the table.
    Preview the DDL statement of the internal table, as shown in the following figure.DDL