Hologres:Manage internal tables

Create an internal table

1. Log on to the Hologres management console.

2. In the top navigation bar, select a region.

3. Click Go to HoloWeb to open the HoloWeb developer page.

4. On the HoloWeb development page, in the top menu bar, click Metadata Management. Then, choose one of the following methods to create an internal table.

   • Method 1: Click Create Table to create an internal table directly.

   • Method 2: Right-click the target schema or Table under the schema, then select Create Internal Table.

   

5. On the Create Internal Table page, configure the parameters.

   Category	Parameter	Description
   Basic properties	Schema	The schema name. You can select the default public schema or a new schema name.
   	Table name	The name of the new Hologres internal table.
   	Description	The description of the new Hologres internal table.
   Fields	Field name	The identifier for each column in the table.
   	Data type	The data type of the field.
   	Primary key	The unique identifier for each data entry in the table.
   	Nullable	Indicates whether the field can be set to null.
   	Array	An ordered sequence of elements.
   	Description	The description of the field.
   	Operations	Includes Delete, Up, and Down.
   Properties	Storage mode	Includes three storage modes: Column-oriented Storage, Row-oriented Storage, and Row-column Storage. The default is Column-oriented Storage.
   	Table data time to live (seconds)	Calculated from the first data write. After the time to live expires, the table data is purged within a certain period (no fixed timeframe). The default time to live is Permanent.
   	Binlog	Indicates whether binary logging (Binlog) is enabled for the table. For more information, see Subscribe to Hologres Binlog.
   	Binlog time to live	The time to live for Binlog. For more information, see Subscribe to Hologres Binlog. The default time to live is Permanent.
   	Distribution column	distribution_key. For more information, see Distribution Key.
   	Segment column	event_time_column . For more information, see Event Time Column (Segment Key).
   	Clustering column	clustering_key. For more information, see Clustering Key.
   	Dictionary encoding column	dictionary_encoding_columns. For more information, see Dictionary Encoding.
   	Bitmap column	bitmap_columns. For more information, see Bitmap Index.
   Partitioned table	N/A	Select a partition field.

6. In the upper-right corner of the page, click Submit. After submission, refresh the corresponding schema on the left to display the new internal table.

   Click Query Table in the upper-right corner of the table editing page to jump to the SQL query window and query using SQL statements.

Edit an internal table

1. In the navigation pane on the left, click Logged-on Instances to display all logged-on instance names.

2. Click Database under the target instance to display all created databases.

3. Click Schema under the target database, then click Table to display all created internal tables.

4. Right-click the target internal table, then select Open Table.

5. In the upper-right corner of the page, click Edit Table.

6. At the bottom of the page, click Add Field to add table fields visually. You can also obtain the corresponding SQL statements in the Operational Logs editing box to view task operational information.

   Note

   Edit TableDeleting existing table fields is not currently supported.

7. Click Commit Table to complete editing the current internal table.

Delete an internal table

1. In the navigation pane on the left, query the target internal table on the Logged-on Instances page.

   For steps to query the target internal table, see steps 1 to 3 in Edit an internal table.

2. Right-click the target internal table, then select Delete Table.

3. Click OK.

Data preview

1. In the navigation pane on the left, query the target internal table on the Logged-on Instances page.

   For steps to query the target internal table, see steps 1 to 3 in Edit an internal table.

2. Double-click the target internal table. On the table editing page, click Data Preview.

   The following image shows an example of internal table data preview.

DDL preview

1. In the navigation pane on the left, query the target internal table on the Logged-on Instances page.

   For steps to query the target internal table, see steps 1 to 3 in Edit an internal table.

2. Double-click the target internal table. On the table editing page, click DDL Statements.

   The following image shows an example of a DDL statement preview.

References

You can also create, modify, and delete internal tables using SQL statements. For more information, see:

• CREATE TABLE

• CREATE TABLE AS

• CREATE TABLE LIKE

• ALTER TABLE

• DROP TABLE

• Physical Partitioned Table