docs/topics/impala_copy_testcase.xml

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<!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
<concept id="impala_copy_testcase" rev="4.3.0 IMPALA-11901">
  <title>Copy Testcase Statements</title>
  <prolog>
    <metadata>
      <data name="Category" value="Impala"/>
      <data name="Category" value="SQL"/>
      <data name="Category" value="Copy Testcase"/>
      <data name="Category" value="Data Analysts"/>
      <data name="Category" value="Developers"/>
      <data name="Category" value="Tables"/>
      <data name="Category" value="ETL"/>
      <data name="Category" value="Ingest"/>
    </metadata>
  </prolog>
  <conbody>
    <p>The <codeph>COPY TESTCASE</codeph> statement allows users to export table or view metadata
      involved in a query, allowing developers to replay the metadata in a local cluster for testing
      and debugging purposes.</p>
  </conbody>
  <concept id="concept_erz_l3j_wdc">
    <title>Exporting Metadata to a File</title>
    <conbody>
      <p>Use the following syntax to dump
        metadata:<codeblock id="codeblock_bzf_g3j_wdc">COPY TESTCASE TO &lt;hdfs/s3 dirpath> &lt;query stmt></codeblock></p>
      <p><b>Example:</b><codeblock id="codeblock_e4t_p3j_wdc">COPY TESTCASE TO '/tmp' SELECT * FROM functional_parquet.alltypes;
</codeblock></p>
      <p><b>Output:</b><codeblock id="codeblock_u44_r3j_wdc">
+--------------------------------------------------------------------------------------+
| Test case data output path                                                           |
+--------------------------------------------------------------------------------------+
| hdfs://localhost:20500/tmp/impala-testcase-data-f41f7b14-dfc8-408b-ac3b-ef49fc3e0a83 |
+--------------------------------------------------------------------------------------+
</codeblock></p>
    </conbody>
  </concept>
  <concept id="concept_d1v_3sp_wdc">
    <title>Loading Metadata into a Target Cluster</title>
    <conbody>
      <p>To load the previously exported metadata, use the following
        syntax:<codeblock id="codeblock_hkg_ksp_wdc">COPY TESTCASE FROM &lt;hdfs/s3 testcase file path></codeblock></p>
      <p><b>Example:</b><codeblock id="codeblock_hrq_lsp_wdc">COPY TESTCASE FROM '/tmp/impala-testcase-data-f41f7b14-dfc8-408b-ac3b-ef49fc3e0a83';</codeblock></p>
      <p><b>Output:</b><codeblock id="codeblock_oqg_nsp_wdc">
+----------------------------------------------------------------------------------------------------------------+
| summary                                                                                                        |
+----------------------------------------------------------------------------------------------------------------+
| Testcase generated using Impala version 4.5.0-SNAPSHOT. 1 db(s), 1 table(s) and 0 view(s) imported for query:  |
|                                                                                                                |
| SELECT * FROM functional_parquet.alltypes                                                                      |
+----------------------------------------------------------------------------------------------------------------+
</codeblock></p>
    </conbody>
  </concept>
  <concept id="concept_tvd_psp_wdc">
    <title>Using the Imported Metadata</title>
    <conbody>
      <p>To use the imported metadata in query planning, enable the planner testcase
        mode:<codeblock id="codeblock_rzj_rsp_wdc">SET PLANNER_TESTCASE_MODE=true;</codeblock></p>
      <p>You can now interact with the metadata using commands
        like:<codeblock id="codeblock_g1r_ssp_wdc">SHOW COLUMN STATS functional_parquet.alltypes;</codeblock></p>
    </conbody>
  </concept>
</concept>