#110: Added overview table with supported features (#124)

README.md

@@ -30,7 +30,6 @@ Exasol Cloud Storage Extension provides [Exasol][exasol] user-defined functions
 For more information please check out the following guides.
 
 * [User Guide](doc/user_guide/user_guide.md)
-* [Delta Format Import](doc/user_guide/delta_format.md)
 * [Changelog](doc/changes/changelog.md)
 
 ## Information for Contributors

doc/changes/changes_1.0.0.md

@@ -20,6 +20,7 @@
 ## Documentation
 
 * #89: Increased the default number of characters for file path (PR #105).
+* #110: Added overview table with supported features (PR #124).
 
 ## Dependency Updates
 

doc/user_guide/user_guide.md

@@ -19,15 +19,100 @@ Parquet, Avro or Orc.
 - [Azure Blob Storage](#azure-blob-storage)
 - [Azure DataLake Gen1 Storage](#azure-data-lake-gen1-storage)
 - [Azure DataLake Gen2 Storage](#azure-data-lake-gen2-storage)
+- [Delta Format](#delta-format)
+
+## Overview
+
+Here an overview of the supported features.
+
+<table>
+  <tr>
+    <th rowspan="2">Import</th>
+    <th rowspan="2"></th>
+    <th colspan="4"></th>
+  </tr>
+  <tr>
+    <th>Parquet</th>
+    <th>Avro</th>
+    <th>Orc</th>
+    <th>Delta</th>
+  </tr>
+  <tr>
+    <td>AWS</td>
+    <td>S3</td>
+    <td rowspan="1" align="center">&#10003;</td>
+    <td rowspan="1" align="center">&#10003;</td>
+    <td rowspan="1" align="center">&#10003;</td>
+    <td rowspan="1" align="center">&#10003;</td>
+  </tr>
+  <tr>
+    <td>GCP</td>
+    <td>Google Cloud Storage</td>
+    <td rowspan="1" align="center">&#10003;</td>
+    <td rowspan="1" align="center">&#10003;</td>
+    <td rowspan="1" align="center">&#10003;</td>
+    <td rowspan="1" align="center"></td>
+  </tr>
+  <tr>
+    <td rowspan="3" align="center">Azure</td>
+    <td>Blob Storage</td>
+    <td rowspan="3" align="center">&#10003;</td>
+    <td rowspan="3" align="center">&#10003;</td>
+    <td rowspan="3" align="center">&#10003;</td>
+    <td rowspan="3" align="center">&#10003;</td>
+  </tr>
+  <tr>
+    <td>Data Lake (Gen1) Storage</td>
+  </tr>
+  <tr>
+    <td>Data Lake (Gen2) Storage</td>
+  </tr>
+  <tr></tr>
+  <tr>
+    <th rowspan="2">Export</th>
+    <th rowspan="2"></th>
+    <th colspan="4"></th>
+  </tr>
+  <tr>
+    <th>Parquet</th>
+    <th>Avro</th>
+    <th>Orc</th>
+    <th>Delta</th>
+  </tr>
+  <tr>
+    <td>AWS</td>
+    <td>S3</td>
+    <td rowspan="6" align="center">&#10003;</td>
+    <td rowspan="6" align="center"></td>
+    <td rowspan="6" align="center"></td>
+    <td rowspan="6" align="center"></td>
+  </tr>
+  <tr>
+    <td>GCP</td>
+    <td>Google Cloud Storage</td>
+  </tr>
+  <tr>
+  	<td rowspan="4">Azure</td>
+  </tr>
+  <tr>
+    <td>Blob Storage</td>
+  </tr>
+  <tr>
+    <td>Data Lake (Gen1) Storage</td>
+  </tr>
+  <tr>
+    <td>Data Lake (Gen2) Storage</td>
+  </tr>
+</table>
 
 ## Getting Started
 
-We assume you have an Exasol cluster running with a version `6.0` or above.
+The `cloud-storage-extension` works for all the supported Exasol versions.
 
 ### Supported Data Formats
 
 We support the Parquet, Avro and Orc formats when importing data from cloud
-storages into an Exasol table.  However, we export Exasol tables only as Parquet
+storages into an Exasol table. However, we export Exasol tables only as Parquet
 data to storage systems.
 
 ### Supported Cloud Storage Systems
@@ -871,3 +956,60 @@ INTO SCRIPT CLOUD_STORAGE_EXTENSION.EXPORT_PATH WITH
 ```
 
 The bucket path should start with an `abfs` or `abfss` URI scheme.
+
+## Delta Format
+
+[Delta format][delta-io] is an open-source storage layer that brings ACID
+transaction properties to Apache Spark and other blob storage systems.
+
+Using the Exasol Cloud Storage Extension, it is now possible to import data from
+the Delta format.
+
+### Import Delta Formatted Data
+
+Like other cloud storage systems, you can run the Exasol IMPORT SQL statement to
+import the data from the Delta format.
+
+Here is an example of import delta formatted data from Amazon S3:
+
+```sql
+CREATE OR REPLACE CONNECTION S3_CONNECTION
+TO ''
+USER ''
+IDENTIFIED BY 'S3_ACCESS_KEY=<AWS_ACCESS_KEY>;S3_SECRET_KEY=<AWS_SECRET_KEY>';
+
+IMPORT INTO <schema>.<table>
+FROM SCRIPT CLOUD_STORAGE_EXTENSION.IMPORT_PATH WITH
+  BUCKET_PATH     = 's3a://<S3_PATH>/import/delta/data/*'
+  DATA_FORMAT     = 'DELTA'
+  S3_ENDPOINT     = 's3.<REGION>.amazonaws.com'
+  CONNECTION_NAME = 'S3_CONNECTION'
+  PARALLELISM     = 'nproc()*<MULTIPLIER>';
+```
+
+### Supported Cloud Storage Systems
+
+Currently, cloud-storage-extension supports importing delta formatted data from
+Amazon S3, Azure Blob Storage and Azure Data Lake Storage Gen1 and Gen2 storage
+systems.
+
+You can read more about the supported storage requirements and configuration on
+the [delta.io/delta-storage.html][delta-storage] page.
+
+### Delta Snapshot
+
+When running the import SQL statement, we first query the [latest
+snapshot][delta-history] of the Delta format and only import the data from the
+latest snapshot version. Thus, each import from the Delta format will import the
+snapshot data to the Exasol table.
+
+### Schema Evolution
+
+Delta format supports schema evolution and the import statement queries the
+latest schema defined in the Delta format. Therefore, users should update the
+Exasol table schema manually before the import if the schema in the delta format
+changes.
+
+[delta-io]: https://delta.io/
+[delta-storage]: https://docs.delta.io/latest/delta-storage.html
+[delta-history]: https://docs.delta.io/latest/delta-utility.html#history