Exploring the BULKLOAD Option with SAS/ACCESS to Hadoop

Attention : This code requires administrator privileges.

The script illustrates the use of `PROC APPEND` with the `SAS^©/ACCESS to Hadoop` interface. It executes three distinct tests. The first uses `BULKLOAD=YES` for a fast load of the `sashelp.cars` table. The second performs the same operation without `BULKLOAD` for comparison. The third test shows how to load data while specifying an underlying storage format, here `Parquet`, in Hadoop. Each test is followed by a cleanup step via `PROC SQL` to drop the created table, making the script re-executable.

Data Analysis

Type : MIXTE

The data source is the `sashelp.cars` table, which is an internal SAS example table. The destination is an external Hadoop database, connected via a `libname`. The script does not read external data; it writes to it.

1 Code Block

LIBNAME

Explanation :
Defines a connection to a Hadoop server via the SAS/ACCESS to Hadoop interface. It also enables tracing options (`sastrace`) to record detailed information about the interaction with the database in the SAS log.

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1	LIBNAME mycdh hadoop server="quickstart.cloudera" user=cloudera password=cloudera;
2	options sastrace=',,,d' sastraceloc=saslog nostsuffix;
3

2 Code Block

PROC APPEND Data

Explanation :
This block loads data from the `sashelp.cars` table into a new `cars` table on the Hadoop server. The `bulkload=yes` option activates bulk loading mode, optimized for large volume data transfers. The table is then dropped with `PROC SQL` to clean up the environment.

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1	PROC APPEND base=mycdh.cars (bulkload=yes)
2	DATA=sashelp.cars;
3	RUN;
4
5	PROC SQL;
6	drop TABLE mycdh.cars;
7	QUIT;

3 Code Block

PROC APPEND Data

Explanation :
This block performs the same load as the previous one but without the `bulkload=yes` option. This allows comparison of the performance difference between a standard load (potentially row-by-row) and a bulk load. The table is then dropped.

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1	PROC APPEND base=mycdh.cars
2	DATA=sashelp.cars;
3	RUN;
4
5	PROC SQL;
6	drop TABLE mycdh.cars;
7	QUIT;

4 Code Block

PROC APPEND Data

Explanation :
This block loads the data again, but uses the `dbcreate_table_opts` option to pass a specific instruction to Hadoop when creating the table. Here, it requests that the table be stored in 'Parquet' file format, a highly performant columnar storage format. The table is finally dropped.

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1	PROC APPEND base=mycdh.cars (dbcreate_table_opts='stored as parquetfile')
2	DATA=sashelp.cars;
3	RUN;
4
5	PROC SQL;
6	drop TABLE mycdh.cars;
7	QUIT;

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