Staging for SingleStore - DSS 6 | Data Source Solutions Documentation

Documentation: Staging for SingleStore - DSS 6 | Data Source Solutions Documentation

Staging for SingleStore

While running Burst Integrate and Bulk Refresh, Data Source Solutions DSS can stream data into a target database straight over the network into a bulk loading interface specific for each DBMS (e.g. direct-path-load in Oracle), or else DSS put data into a temporary directory (‘staging file') before loading data into a target database.

For best performance, DSS performs Burst Integrate and Bulk Refresh into SingleStore location using staging files. DSS implements the file staging in SingleStore by using either of the following methods:

Server File Staging - The SingleStore Server directly reads the staging files and ingest them into the target tables.
1. DSS first writes data into the local staging directory on the machine where DSS is installed.
2. DSS then uses the SQL command <b>load data</b> to ingest the data into the SingleStore target tables. Here, the SingleStore Server will directly read the staging files from the staging folder and load them into the target tables.

The following conditions should be satisfied to use this method:

-   The DSS database **User** should have **FILE** permission.
-   The system variable (of SingleStore server) **secure_file_priv** should be set to "" (blank).

Client File Staging - The SingleStore Client directly reads the staging files and pass them to the SingleStore Server, which then ingest them into the target tables.
- Use case 1: DSS and SingleStore Server are installed on separate machines.

In this use case, the SingleStore Client must be installed on the same machine where DSS is installed.

    1.  DSS first writes data into the local staging directory on the machine where DSS is installed.
    2.  DSS then uses the SQL command `<b>load data local</b>` to ingest the data into SingleStore target tables. Here, the SingleStore Client will directly read the staging files from the staging folder and copy them into the machine where SingleStore Server is installed. The SingleStore Server will read the staging files received from the MySQL Client and load them into the target tables.

-   **Use case 2**: If you do not want to give the **FILE** privilege to the DSS database **User**.

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In this use case, the SingleStore Server, and SingleStore Client must be installed on the same machine.

    1.  DSS first writes data into the staging directory on the machine where DSS is installed.
    2.  DSS then uses the SQL command `<b>load data local</b>` to ingest the data into SingleStore target tables. Here, the SingleStore Client will directly read the staging files from the staging folder and pass them to the SingleStore Server, which will then read the staging files received from the SingleStore Client and load them into the target tables.

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The following condition should be satisfied to use this method:

-   The system variable (of SingleStore client and server) **local_infile** should be enabled.

Configuring Staging

DSS must be configured to stage data on the local directory before loading it into SingleStore. For staging the data on local directory and perform Burst Integrate and Bulk Refresh into SingleStore, the following are required:

Depending on the Staging method used, the following must be configured in SingleStore:
- Server Based Staging,
  1. The database User must have FILE privilege.
  2. The system variable (of SingleStore server) secure_file_priv should be set to "" (blank).
- Client Based Staging
  1. The system variable (of SingleStore client and server) local_infile should be enabled.
Define the following location properties (while creating a location or by editing the existing location's source and target properties) for the SingleStore location:

The Location Property equivalent to the UI field is shown inside (bracket) below.

1.  **Staging Directory Is Local** ([**Staging_Directory_Is_Local**](/docs/dss6-property-reference-location-properties#stagingdirectoryislocal)): Indicates that staging files are created in the local directory. This field is automatically selected by default and it cannot be unselected.

2.  **STAGING DIRECTORY** ([**Staging_Directory**](/docs/dss6-property-reference-location-properties#stagingdirectory)): Local directory path where DSS will create the temporary staging files (e.g. **/my_staging_dir**).

3.  **STAGING DIRECTORY AS VISIBLE FROM THE DATABASE** ([**Staging_Directory_Database**](/docs/dss6-property-reference-location-properties#stagingdirectorydatabase)): Directory path from where SingleStore will access the temporary staging files (e.g. **/my_staging_dir**). This field must be left blank if the staging method is **Client Based Staging**.

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If the staging method is Client Based Staging, then only the STAGING DIRECTORY must be specified.
- If the staging method is Server Based Staging, then both STAGING DIRECTORY and STAGING DIRECTORY AS VISIBLE FROM THE DATABASE must be specified.