Add Exasol connector

.github/workflows/ci.yml

@@ -355,6 +355,7 @@ jobs:
             !:trino-docs,
             !:trino-druid,
             !:trino-elasticsearch,
+            !:trino-exasol,
             !:trino-faulttolerant-tests,
             !:trino-filesystem,
             !:trino-filesystem-azure,
@@ -466,6 +467,7 @@ jobs:
             - { modules: plugin/trino-delta-lake, profile: fte-tests }
             - { modules: plugin/trino-druid }
             - { modules: plugin/trino-elasticsearch }
+            - { modules: plugin/trino-exasol }
             - { modules: plugin/trino-google-sheets }
             - { modules: plugin/trino-hive }
             - { modules: plugin/trino-hive, profile: fte-tests }
@@ -527,7 +529,7 @@ jobs:
         timeout-minutes: 10
         with:
           cache: restore
-          cleanup-node: ${{ format('{0}', matrix.modules == 'plugin/trino-singlestore') }}
+          cleanup-node: ${{ format('{0}', matrix.modules == 'plugin/trino-singlestore' || matrix.modules == 'plugin/trino-exasol') }}
           java-version: ${{ matrix.jdk != '' && matrix.jdk || '22' }}
       - name: Maven Install
         run: |

core/trino-server/src/main/provisio/trino.xml

@@ -89,6 +89,12 @@
         </artifact>
     </artifactSet>
 
+    <artifactSet to="plugin/exasol">
+        <artifact id="${project.groupId}:trino-exasol:zip:${project.version}">
+            <unpack />
+        </artifact>
+    </artifactSet>
+
     <artifactSet to="plugin/exchange-filesystem">
         <artifact id="${project.groupId}:trino-exchange-filesystem:zip:${project.version}">
             <unpack />

docs/src/main/sphinx/connector.md

@@ -15,6 +15,7 @@ ClickHouse      <connector/clickhouse>
 Delta Lake      <connector/delta-lake>
 Druid           <connector/druid>
 Elasticsearch   <connector/elasticsearch>
+Exasol          <connector/exasol>
 Google Sheets   <connector/googlesheets>
 Hive            <connector/hive>
 Hudi            <connector/hudi>

docs/src/main/sphinx/connector/exasol.md

@@ -0,0 +1,195 @@
+---
+myst:
+  substitutions:
+    default_domain_compaction_threshold: '`32`'
+---
+
+# Exasol connector
+
+```{raw} html
+<img src="../_static/img/exasol.png" class="connector-logo">
+```
+
+The Exasol connector allows querying an [Exasol](https://www.exasol.com/) database.
+
+## Requirements
+
+To connect to Exasol, you need:
+
+* Exasol database version 7.1 or higher.
+* Network access from the Trino coordinator and workers to Exasol.
+  Port 8563 is the default port.
+
+## Configuration
+
+To configure the Exasol connector as the ``example`` catalog, create a file
+named ``example.properties`` in ``etc/catalog``. Include the following
+connection properties in the file:
+
+```text
+connector.name=exasol
+connection-url=jdbc:exa:exasol.example.com:8563
+connection-user=user
+connection-password=secret
+```
+
+The ``connection-url`` defines the connection information and parameters to pass
+to the JDBC driver. See the
+[Exasol JDBC driver documentation](https://docs.exasol.com/db/latest/connect_exasol/drivers/jdbc.htm#ExasolURL)
+for more information.
+
+The ``connection-user`` and ``connection-password`` are typically required and
+determine the user credentials for the connection, often a service user. You can
+use {doc}`secrets </security/secrets>` to avoid using actual values in catalog
+properties files.
+
+:::{note}
+If your Exasol database uses a self-signed TLS certificate you must
+specify the certificate's fingerprint in the JDBC URL using parameter
+``fingerprint``, e.g.: ``jdbc:exa:exasol.example.com:8563;fingerprint=ABC123``.
+:::
+
+```{include} jdbc-authentication.fragment
+```
+
+```{include} jdbc-common-configurations.fragment
+```
+
+```{include} jdbc-domain-compaction-threshold.fragment
+```
+
+```{include} jdbc-case-insensitive-matching.fragment
+```
+
+(exasol-type-mapping)=
+## Type mapping
+
+Because Trino and Exasol each support types that the other does not, this
+connector {ref}`modifies some types <type-mapping-overview>` when reading data.
+Data types may not map the same way in both directions between
+Trino and the data source. Refer to the following sections for type mapping in
+each direction.
+
+### Exasol to Trino type mapping
+
+Trino supports selecting Exasol database types. This table shows the Exasol to
+Trino data type mapping:
+
+```{eval-rst}
+.. list-table:: Exasol to Trino type mapping
+  :widths: 25, 25, 50
+  :header-rows: 1
+
+  * - Exasol database type
+    - Trino type
+    - Notes
+  * - ``BOOLEAN``
+    - ``BOOLEAN``
+    -
+  * - ``DOUBLE PRECISION``
+    - ``REAL``
+    -
+  * - ``DECIMAL(p, s)``
+    - ``DECIMAL(p, s)``
+    -  See :ref:`exasol-number-mapping`
+  * - ``CHAR(n)``
+    - ``CHAR(n)``
+    -
+  * - ``VARCHAR(n)``
+    - ``VARCHAR(n)``
+    -
+  * - ``DATE``
+    - ``DATE``
+    -
+```
+
+No other types are supported.
+
+(exasol-number-mapping)=
+### Mapping numeric types
+
+An Exasol `DECIMAL(p, s)` maps to Trino's `DECIMAL(p, s)` and vice versa
+except in these conditions:
+
+- No precision is specified for the column (example: `DECIMAL` or
+  `DECIMAL(*)`).
+- Scale (`s`) is greater than precision.
+- Precision (`p`) is greater than 36.
+- Scale is negative.
+
+(exasol-character-mapping)=
+### Mapping character types
+
+Trino's `VARCHAR(n)` maps to `VARCHAR(n)` and vice versa if `n` is no greater
+than 2000000. Exasol does not support longer values.
+If no length is specified, the connector uses 2000000.
+
+Trino's `CHAR(n)` maps to `CHAR(n)` and vice versa if `n` is no greater than 2000.
+Exasol does not support longer values.
+
+```{include} jdbc-type-mapping.fragment
+```
+
+(exasol-sql-support)=
+## SQL support
+
+The connector provides {ref}`globally available <sql-globally-available>` and
+{ref}`read operation <sql-read-operations>` statements to access data and
+metadata in the Exasol database.
+
+## Table functions
+
+The connector provides specific {doc}`table functions </functions/table>` to
+access Exasol.
+
+(exasol-query-function)=
+### `query(varchar) -> table`
+
+The `query` function allows you to query the underlying database directly. It
+requires syntax native to Exasol, because the full query is pushed down and
+processed in Exasol. This can be useful for accessing native features which are
+not available in Trino or for improving query performance in situations where
+running a query natively may be faster.
+
+```{include} query-passthrough-warning.fragment
+```
+
+As a simple example, query the `example` catalog and select an entire table::
+
+```sql
+SELECT
+  *
+FROM
+  TABLE(
+    example.system.query(
+      query => 'SELECT
+        *
+      FROM
+        tpch.nation'
+    )
+  );
+```
+
+As a practical example, you can use the
+[WINDOW clause from Exasol](https://docs.exasol.com/db/latest/sql_references/functions/analyticfunctions.htm#AnalyticFunctions):
+
+```sql
+SELECT
+  *
+FROM
+  TABLE(
+    example.system.query(
+      query => 'SELECT
+        id, department, hire_date, starting_salary,
+        AVG(starting_salary) OVER w2 AVG,
+        MIN(starting_salary) OVER w2 MIN_STARTING_SALARY,
+        MAX(starting_salary) OVER (w1 ORDER BY hire_date)
+      FROM employee_table
+      WINDOW w1 as (PARTITION BY department), w2 as (w1 ORDER BY hire_date)
+      ORDER BY department, hire_date'
+    )
+  );
+```
+
+```{include} query-table-function-ordering.fragment
+```