## Clearing and Initializing the Graph Store

There are two aspects to clearing the system: flushing the data and clearing the schema definitions in the catalog. Two different commands are available.

### CLEAR GRAPH STORE

The `CLEAR GRAPH STORE` command flushes all the data out of the graph store (database). By default, the system asks the user to confirm that you really want to discard all the graph data. To force the clear operation and bypass the confirmation question, use the `-HARD` option,

``CLEAR GRAPH STORE -HARD``

Clearing the graph store does not affect the schema.

 Use the `-HARD` option with extreme caution. There is no undo option. `-HARD` must be in all capital letters. `CLEAR GRAPH STORE` stops all the TigerGraph servers (GPE, GSE, RESTPP, Kafka, and Zookeeper). Loading jobs and queries are aborted.

`DROP ALL` clears both the data and the schema.

`RUN LOADING JOB` syntax for concurrent loading
``````RUN LOADING JOB [-noprint] [-dryrun] [-n [i],j] job_name [
USING file_var [="file_path_string"][, file_var [="file_path_string"]]*
[, CONCURRENCY="cnum"][,BATCH_SIZE="bnum"]
]``````

When a concurrent loading job is submitted, it is assigned a job ID number, which is displayed on the GSQL console. The user can use this job ID to refer to the job, for a status update, to abort the job, or to restart the job. These operations are described later in this section.

### Options

#### `-noprint`

By default, the command will print several lines of status information while the loading is running.
If the -noprint option is included, the output will omit the progress and summary details, but it will still display the job id and the location of the log file.

Example of minimal output when `-noprint` option is used
``````Kick off the following job:
JobName: load_videoE, jobid: gsql_demo_m1.1525091090494

#### `-dryrun`

If -dryrun is used, the system will read the data files and process the data as instructed by the job, but will NOT load any data into the graph. This option can be a useful diagnostic tool.

#### `-n [i], j`

The `-n` option limits the loading job to processing only a range of lines of each input data file. The -n flag accepts one or two arguments.

For example, `-n 50` means read lines 1 to 50. `-n 10, 50` means read lines 10 to 50. The special symbol `$` is interpreted as "last line", so `-n 10,$` means reads from line 10 to the end.

### Parameters

Below are the parameters available for the `RUN QUERY` command introduced by the `USING` clause.

#### `filevar` list

The optional `USING` clause may contain a list of file variables. Each file variable may optionally be assigned a `filepath_string`, obeying the same format as in the `CREATE LOADING JOB`. This list of file variables determines which parts of a loading job are run and what data files are used.

• When a loading job is compiled, it generates one RESTPP endpoint for each `filevar` and `filepath_string`. As a consequence, a loading job can be run in parts. When `RUN LOADING JOB` is executed, only those endpoints whose `filevar` or file identifier (`__GSQL_FILENAME_n__`) is mentioned in the `USING` clause will be used. However, if the `USING` clause is omitted, then the entire loading job will be run.

• If a `filepath_string` is given, it overrides the `filepath_string` defined in the loading job. If a particular `filevar` is not assigned a `filepath_string` either in the loading job or in the `RUN LOADING JOB` statement, then an error is reported and the job exits.

#### `CONCURRENCY`

The `CONCURRENCY` parameter sets the maximum number of concurrent requests that the loading job may send to the GPE. The default is 256.

#### `BATCH_SIZE`

The `BATCH_SIZE` parameter sets the number of data lines included in each concurrent request sent to the GPE. The default is 8192.

### Running Loading Jobs as REST Requests

Another way to run a loading job is through the `POST /ddl/{graph_name}` endpoint of the REST++ server. Since the REST++ server has more direct access to the graph processing engine, this can execute more quickly than a `RUN LOADING JOB` statement in GSQL. For details on how to use the endpoint, please see Run a loading job.