Configuring Delete Operation Service
Use the
Delete Operation template to configure an adapter service that deletes a specific row, column family, or column qualifier completely from a selected table. For more information about adapter services, see
Using Adapter Services.
Be sure to review the section
Before Configuring or Managing Adapter Services, before you configure adapter services.
HBase client API provides delete feature at following three levels:
Column Qualifier level :- If you enter any column qualifier in the Columns tab, then the values of that column qualifier are deleted for all the input row ids provided during runtime.
Column Family level: - If you do not enter a value for column qualifier in Columns tab, and if you select a column family in Schema tab, then the values of that column family are deleted for all the input row ids provided during runtime.
Complete Row: - If you do not enter a column qualifier and column family in the table, then the entire records of the input row ids are deleted.
To configure an adapter service using the Delete Operation template
1. In Designer, right-click the package in which the service should be contained and select New > Adapter Service.
2. Select the parent namespace, type a name for the adapter service, and click Next.
3. Select Adapter for Apache HBase as the adapter type and click Next.
4. Select the appropriate Adapter Connection Name and click Next.
5. From the list of available templates, select the Delete Operation template and click Finish
The adapter service editor for the adapter service appears. You can select the Adapter Settings tab at any time to confirm adapter service properties such as the Adapter Name, Adapter Connection Name, and Adapter Service Template as necessary.
6. Select the Schema tab to configure the database table, using the following fields:
Field | Description/Action |
HBase Table | Select a table name from the list of tables. |
Column Family | Displays the list of column families for the selected table name. |
Select | Select the check box for the corresponding column family to query. |
Sampling Range | Specify the number of records to be scanned to get a minimum set of column qualifiers. These column qualifiers are listed in the Columns tab. Value can be entered in the following formats: Input value can be an integer and it should be greater than 0. For example, if you provide Sampling Range: 10, then the service will scan initial 10 records of the selected table. Input value can be the range between two row ids separated by hyphen (-). The start row id and the end row id should be valid row ids, present in the selected table. The start Row Id should be lexicographically smaller than the end Row Id. For example, if you provide Sampling Range: row100-row1000, then the service will scan all the records which contain row ids between row100 to row1000. Note: Sampling is not performed for the values which do not contain the above formats, and the list of column qualifier under Columns tab will remain empty. |
Timestamp Operator | Used along with the Timestamp field. You can select a Timestamp Operator, which can either be EQUAL or LESS_OR_EQUAL. If you select LESS_OR_EQUAL, then all the records whose Timestamp value is less than or equal to the entered Timestamp value gets deleted. The default is EQUAL. |
7. Use the Columns tab to define the column qualifiers using the following fields:
Use the
icon to create a new row as needed. You can use the
icon to fill in all column families to the table.
Use the following fields:
Field | Description/Action |
Row ID Data Type | Select the data type to retrieve the required row id. |
Column Family | Provides the list of column families based on the selection made in the Schema tab. |
Select Column Qualifier | Select the column qualifier which can be retrieved for the corresponding column family. The Select Column Qualifier field is displayed as a drop down list. These values are retrieved based on the sampling range provided in the Schema tab. |
Column Qualifier Type | The Select Column Qualifier field supports the following data types: java.lang.String byte array |
Enter Column Qualifier | Specify the column qualifiers which are not listed in the Select Column Qualifier field. |
Note:
If you change the values of Table Name and Column Family of Schema tab then, the following fields for Columns tab changes:
The values of
Column Family and
Select Column Qualifier changes automatically.
The
Column Family changes automatically, but you need to manually change the values of
Enter Column Qualifier.
8. To verify input or output information for the service, use the Input/Output tab as required.
The below fields are auto generated under input section of Input/Output tab:
Field | Description/Action |
Row Ids | Specify the list of Row Ids to delete the corresponding records. Note: It is mandatory to provide Row Ids as input to delete the records. |
Timestamp | Enter the timestamp to delete a particular version of the records. Note: It works along with Timestamp Operator. |
9. From the File menu, select Save.