title: Column separator mismatch when reading Parquet dataset into H2OFrame after conversion from Delta to Parquet
body: <p>I am attempting to read a multi-file Parquet dataset into an H2OFrame and it results in a column mismatch error:</p>
  <pre><code>H2OResponseError: Server error water.exceptions.H2OIllegalArgumentException:
    Error: Column separator mismatch. One file seems to use &quot;&quot; and the other uses &quot; &quot;.
  </code></pre>
  <p>The dataset is initially converted from Delta to Parquet since H2O doesn't support Delta tables as data sources:</p>
  <pre class="lang-py prettyprint-override"><code># convert from Delta to Parquet
  delta_uri = 's3://my_bucket/path/to/delta/folder/'
  df = spark.read.format('delta').load(delta_uri)
  parquet_uri = 's3://my_bucket/path/to/parquet/folder/'
  df.write.parquet(parquet_uri)
  
  # extract Parquet into H2OFrame (this line is where the error happens)
  data = h2o.import_file(path=parquet_uri)
  </code></pre>
  <p>Is there a way to enforce a single column separator across all Parquet files when making the conversion from Delta to Parquet?</p>
  <p>The H2O cluster is running version 3.34.0.3 of H2O. The code above is being run within a Databricks notebook.</p>